Testing the Canon R5 for Astrophotography


In a format similar to my other popular camera tests, I put the 45-megapixel Canon R5 mirrorless camera through its paces for the demands of astrophotography. 

In a sequel to my popular post from September 2021 where I reviewed the Canon R6 mirrorless camera, here is a similar test of its higher-megapixel companion, the Canon R5. Where the R6 has a modest 20-megapixel sensor with relatively large 6.6-micron pixels, the R5 is (at present) Canon’s highest megapixel camera, with 45 megapixels. Each pixel is only 4.4 microns across, providing higher resolution but risking more noise. 

Is the higher noise noticeable? If so, does that make the R5 less than ideal for astrophotography? To find out, I tested an R5 purchased locally in Calgary from The Camera Store in May 2022. 

NOTE: CLICK orTAP on any image to bring it up full screen for closer inspection. The blog contains a lot of high-res images, so they may take a while to all load. Patience! Thanks! 

All images are © 2022 by Alan Dyer/AmazingSky.com. Use without permission is prohibited.


The Canon R5 uses a full-frame sensor offering 45 megapixels, producing images with 8192 x 5464 pixels, and making 8K video possible.

TL;DR Summary

The Canon R5 proved to be surprisingly low in noise, and has worked very well for nightscape, lunar and deep-sky photography (as shown below), where its high resolution does produce a noticeable improvement to image detail, with minimal penalty from higher noise. Its 8K video capability has a place in shooting the Moon, Sun and solar eclipses. It was not so well suited to shooting videos of auroras. 

This is a stack of 12 x 5-minute exposures with a Sharpstar 94EDPH refractor at f/4.5 and the Canon R5 at ISO 800, taken as a test of the R5 for deep-sky imaging. No filters were employed. Close-ups of sub-frames from this shoot with the R5, and also with the R6 and Ra, are used throughout the review.

R5 Pros

The Canon R5 is superb for its:

  • High resolution with relatively low noise
  • ISO invariant sensor performance for good shadow recovery 
  • Good live view display with ISO boost in Movie mode 
  • 8K video has its attraction for eclipse photography
  • Good top LCD information screen missing in the R6
  • No magenta edge “amp glow” that the R6 shows
  • Higher 6x and 15x magnifications for precise manual focusing
  • Good battery life 
  • Pro-grade Type N3 remote port

R5 Cons

The Canon R5 is not so superb for its:

  • Noise in stills and movies is higher than in the R6
  • Propensity for thermal-noise hot pixels in shadows
  • Not so suitable for low-light video as the R6
  • Overheating in 8K video
  • Live View image is not as bright as in the R6’s Movie mode
  • High cost! 

The flip-out screen of the R5 (and all recent Canon cameras) requires an L-bracket with a notch in the side (a Small Rig unit is shown here) to accommodate the tilting screen.  

CHOOSING THE R5

Since late 2019 my main camera for all astrophotography has been the Canon Ra, a limited-edition version of the original R, Canon’s first full-frame mirrorless camera that started the R series. The Ra had a special infra-red cutoff filter in front of the sensor that passed a higher level of visible deep-red light, making it more suitable for deep-sky astrophotography than a standard DSLR or DSLM (mirrorless) camera. The Ra was discontinued after two years on the market, a lifetime similar to Canon’s previous astronomical “a” models, the 20Da and 60Da. 

I purchased the Canon R6 in late 2021, primarily to use it as a low-light video camera for aurora photography, replacing the Sony a7III I had used for several years and reviewed here. Over the last year, I sold all my non-Canon cameras, as well as the Canon 6D MkII DSLR (reviewed here), to consolidate my camera gear to just Canon mirrorless cameras and lenses. 

The R6 has proven to be an able successor to the Sony for me, with the R6’s modest megapixel count and larger pixels making it excellent for low-light video. But the higher resolution of the R5 was still attractive. So I have now added it to my Canon stable. Since doing so, I have put it through several of my standard tests to see how suitable it is for the demands of astrophotography, both stills and video. 

Here are my extensive results, broken down by various performance criteria. I hope you will find my review useful in helping you make a purchase decision.


LIVE VIEW FRAMING

This compares the back-of-camera views of the R5 vs. the R6, with both set to their highest ISO in Movie mode for the brightest preview image.

First, why go mirrorless at all? For astrophotography, the big difference compared to even a high-end DSLR, is how much brighter the “Live View” image is when shooting at night. DSLM cameras are always in Live View – even the eye-level viewfinder presents a digital image supplied by the sensor. 

And that image is brighter, often revealing more than what a DSLR’s optical viewfinder can show, a great advantage for framing nightscape scenes, and deep-sky fields at the telescope.

The R5 certainly presents a good live view image. However, it is not as bright nor as detailed as what the R6 can provide when placed in its Movie mode and with the ISO bumped up to the R6’s highest level of ISO 204,800, where the Milky Way shows up, live! 

The R5 only goes as high as ISO 51,200, and so as I expected it does not provide as bright or detailed a preview at night as the R6 can. However, the R5 is better than the original R for live-view framing, and better than any Canon DSLR I’ve used. 


LIVE VIEW FOCUSING

As with other Canon mirrorless cameras, the R5 offers a Focus Assist overlay (top) to aid manual focusing. It works on bright stars. It also has a 6x and 15x magnifications for even more precise focusing.

Like the R6, the R5 can autofocus accurately on bright stars and planets. By comparison, while the Ra can autofocus on distant bright lights, it fails on bright stars or planets. 

Turning on Focus Peaking makes stars turn red, yellow or blue (your choice of colours) when they are in focus, as a reassuring confirmation. 

Turning on Focus Guide provides the arrowed overlays shown above.

In manual focus, an additional Focus Aid overlay, also found in the R6, provides arrows that close up and turn green when in focus on a bright star or planet. 

Or, as shown above, you can zoom in by 6x or 15x to focus by eye the old way by examining the star image. These are magnification levels higher than the 5x and 10x of the R6 and most other Canon cameras, and are a great aid to precise focusing, necessary to make full use of the R5’s high resolution, and the sharpness of Canon’s RF lenses. The 15x still falls short of the Ra’s 30x for ultra-precise focusing on stars, but it’s a welcome improvement nonetheless. 

In all, while the R5 is not as good as the R6 for framing in low light, it is better for precise manual focusing using its higher 15x magnification. 


NOISE PERFORMANCE — NIGHTSCAPES

The key camera characteristic for astrophoto use is noise. There is no point in having lots of resolution if, at the high ISOs we use for most astrophotography, the detail is lost in noise. But I was pleasantly surprised that proved not to be the case with the R5.

As I show below, noise is well controlled, making the R5 usable for nightscapes at ISOs up to 3200, if not 6400 when needed in a pinch. 

This compares the noise on a dark nightscape at the typical ISOs used for such scenes. A level of noise reduction shown has been applied in Camera Raw. 

With 45 megapixels, at the upper end of what cameras offer today, the R5 has individual pixels, or more correctly “photosites,” that are each 4.4 microns in size, the “pixel pitch.” 

This is still larger than the 3.7-micron pixels in a typical 24-megapixel cropped-frame camera like the Canon R10, or the 3.2-micron pixels found in a 32-megapixel cropped-frame camera like the Canon R7. Both are likely to be noisier than the R5, though will provide even higher resolution, as well as greater magnification with any given lens or telescope. 

By comparison, the 30-megapixel full-frame R (and Ra) has a pixel pitch of 5.4 microns, while the 20-megapixel R6’s pixel pitch is a generous 6.6 microns. Only the 12-megapixel Sony a7SIII has larger 8.5-micron pixels, making it the low-light video champ.

The bigger the photosites (i.e. the larger the pixel pitch), the more photons each photosite can collect in a given amount of time – and the more photons they can collect, period, before they overfill and clip highlights. More photons equals more signal, and therefore a better signal-to-noise ratio, while the greater “full-well depth” yields higher dynamic range. 

However, each generation of camera improves the signal-to-noise ratio by suppressing noise via its sensor design and improved signal processing hardware and firmware. The R5 and R6 each use Canon’s latest DIGIC X processor. 

This compares the R5 to the R6 and Ra cameras at the high ISOs of 3200 and 6400 often used for Milky Way nightscapes. 

In nightscapes the R5 did show more noise at high ISOs, especially at ISO 6400, than the R6 and Ra, but the difference was not large, perhaps one stop at most, if that. What was noticeable was the presence in the R5 of more hot pixels from thermal noise, as described later. 

This compares the R5 to the R6 and Ra cameras at the more moderate ISOs of 800 and 1600 used for brighter nightscapes. 

At slower ISOs the R5 showed a similar level of noise as the R6 and Ra, but a finer-grained noise than the R6, in keeping with the R5’s smaller pixels. In this test set, the R5 did not exhibit noticeably more noise than the other two cameras. This was surprising.

NOTE: In these comparisons I have not resampled the R5 images down to the megapixel count of the R6 to equalize them, as that’s not what you would do if you bought an R5. Instead, I have magnified the R6 and Ra’s smaller images so we examine the same area of each camera’s images. 

As with the R6, I also saw no “magic ISO” setting where the R5 performed better than at other settings. Noise increased in proportion to the ISO speed. The R5 proved perfectly usable up to ISO 3200, with ISO 6400 acceptable for stills when necessary. But I would not recommend the R5 for those who like to shoot Milky Way scenes at ISO 12,800. 

For nightscapes, a good practice that would allow using lower ISO speeds would be to shoot the sky images with a star tracker, then take separate long untracked exposures for the ground.

NOTE: In my testing I look first and foremost at actual real-world results. For those interested in more technical tests and charts, I refer you to DxOMark’s report on the Canon R5.  


NOISE PERFORMANCE — DEEP-SKY

This compares the R5 at the typical ISO settings used for deep-sky imaging, with no noise reduction applied to the raw files for this set. The inset shows the portion of the frame contained in the blow-ups.

Deep-sky imaging with a tracking mount is more demanding, due to its longer exposures of up to several minutes for each “sub-frame.” 

On a series of deep-sky exposures through a telescope, above, the R5 again showed quite usable images up to ISO 1600 and 3200, with ISO 6400 a little too noisy in my opinion unless a lot of noise reduction was applied or many images were shot to stack later.  

This compares the R5 to the R6 and Ra cameras at ISO 6400, higher than typically used for deep-sky imaging. No noise reduction was applied to the raw files.

As with the nightscape set, at high ISOs, such as at ISO 6400, the R5 did show more noise than the R6 and Ra, as well as more colour splotchiness in the dark sky, and lower contrast. The lower dynamic range of the R5’s smaller pixels is evident here. 

Just as with nightscapes, the lesson with the R5 is to keep the ISO low if at all possible. That means longer exposures with good auto-guiding, but that’s a best practice with any camera.

This compares the R5 to the R6 and Ra cameras at the lower ISOs of 800 and 1600 best for deep-sky imaging, for better dynamic range. No noise reduction was applied to the raw files. 

At lower ISOs that provide better dynamic range, shown above, the difference in noise levels between the three cameras was not that obvious. Each camera presented very similar images, with the R6 having a coarser noise than the Ra and R5. 

In all, I was surprised the R5 performed as well as it did for deep-sky imaging. See my comments below about its resolution advantage. 


ISO INVARIANCY

The flaw in many Canon DSLRs, one documented in my 2017 review of the 6D Mark II, was their poor dynamic range due to the lack of an ISO invariant sensor design. 

Canon R-series mirrorless cameras have largely addressed this weakness. As with the R and R6, the sensor in the R5 appears to be nicely ISO invariant. 

Where ISO invariancy shows itself to advantage is on nightscapes where the starlit foreground is often dark and underexposed. Bringing out detail in the shadows in raw files requires a lot of Shadow Recovery or increasing the Exposure slider. Images from an ISO invariant sensor can withstand the brightening “in post” far better, with minimal noise increase or degradations such as a loss of contrast, added banding, or horrible discolourations. 

This shows the same scene with the R5 progressively underexposed by shooting at a lower ISO then boosted in exposure in Adobe Camera Raw.

As I do for such tests, I shot sets of images at the same shutter speed, one well-exposed at a high ISO, then several at successively lower ISOs to underexpose by 1 to 4 stops. I then brightened the underexposed images by increasing the Exposure in Camera Raw by the same 1 to 4 stops. In an ideal ISO invariant sensor, all the images should look the same. 

The R5 performed well in images underexposed by up to 3 stops. Images underexposed by 4 stops started to fall apart with low contrast and a magenta cast. This was worse performance than the R6, which better withstood underexposure by as much as 4 stops, and fell apart at 5 stops of underexposure. 

While it can withstand underexposure, the lesson with the R5 is to still expose nightscapes as well as possible, likely requiring a separate longer exposure for the dark ground. Expose to the right! Don’t depend on being able to save the image by brightening “in post.” But again, that’s a best practice with any camera. 


THERMAL NOISE

Here I repeat some of the background information from my R6 review. But it bears repeating, as even skilled professional photographers often misunderstand the various forms of noise and how to mitigate them.

All cameras will exhibit thermal noise in long exposures, especially on warm nights. This form of heat-induced noise peppers the shadows with bright or “hot” pixels, often brightly coloured. 

This is not the same as the shot and read noise that adds graininess to high-ISO images and that noise reduction software can smooth out later in post. 

Thermal noise is more insidious and harder to eliminate in processing without harming the image. However, Monika Deviat offers a clever method here at her website

This shows a long-exposure nightscape scene both without and with Long Exposure Noise Reduction turned on. LENR eliminated most, though not all, of the hot pixels in the shadows. 

I found the R5 was prone to many hot pixels in long nightscape exposures where they show up in dark, underexposed shadows. I did not find a prevalence of hot pixels in well-exposed deep-sky images. 


LONG EXPOSURE NOISE REDUCTION

With all cameras a setting called Long Exposure Noise Reduction (LENR) eliminates this thermal noise by taking a “dark frame” and subtracting it in-camera to yield a raw file largely free of hot pixels, and other artifacts such as edge glows. 

The LENR option on the R5 did eliminate most hot pixels, though sometimes still left, or added, a few (or they might be cosmic ray hits). LENR is needed more on warm nights, and with longer exposures at higher ISOs. So the extent of thermal noise in any camera can vary a lot from shoot to shoot, and season to season.

This compares a long exposure of nothing (with the lens cap on), both without LENR (left) and with LENR (right), to show the extent of just the thermal noise.

The comparison above shows just thermal noise in long exposures with and without LENR, to show its effectiveness. However, bear in mind in this demo the raw files have been boosted a lot in exposure and contrast (using DxO PhotoLab with the settings shown) to exaggerate the visibility of the noise. 

Like the R6, when LENR is actively taking a dark frame, the R5’s rear screen indicates “Busy,” which is annoyingly bright at night, exactly when you would be employing LENR. To hide this display, the only option is to close the screen. Instead, the unobtrusive top LCD screen alone should be used to indicate a dark frame is in progress. It does with the Ra, though Busy also displays on its rear screen as well, which is unnecessary.

As with all mirrorless cameras, the R5 lacks the “dark frame buffer” present in Canon full frame DSLRs that allows several exposures to be taken in quick succession even with LENR on.

Long Exposure Noise Reduction is useful when the gap in time between exposures it produces is not critical.

With all Canon R cameras, turning on LENR forces the camera to take a dark frame after every light frame, doubling the time it takes to finish every exposure. That’s a price many photographers aren’t willing to pay, but on warm nights I find it can be essential, and a best practice, for the reward of cleaner images out of camera. I found it is certainly a good practice with the R5. 

TIP: If you find hot pixels are becoming more obvious over time, try this trick: turn on the Clean Manually routine for 30 seconds to a minute. In some cameras this can remap the hot pixels so the camera can better eliminate them. 


STAR QUALITY 

Using LENR with the R5 did not introduce any oddities such as oddly-coloured, green or wiped-out stars. Even without LENR I saw no evidence of green stars, a flaw that plagues some Sony cameras at all times, or Nikons when using LENR. 

This is a single developed raw frame from the stack of four minute exposures used to create the final image shown at the top. It shows sharp and nicely coloured stars, with no odd green stars. 

Canons have always been known for their good star colours, and the R5 maintains the tradition. According to DPReview the R5 has a mild low-pass anti-alias filter in front of its sensor. Cameras which lack such a sensor filter do produce sharper images, but stars that occupy only one or two pixels might not de-Bayer properly into the correct colours. I did not find that an issue with the R5.

As in the R6, I also saw no evidence of “star-eating,” a flaw Nikons and Sonys have been accused of over the years, due to aggressive in-camera noise reduction even on raw files. Canons have largely escaped charges of star-eating. 


RED SENSITIVITY 

The R5 I bought was a stock “off-the-shelf” model. It is Canon’s now-discontinued EOS Ra that was “filter-modified” to record a greater level of the deep-red wavelength from red nebulas in the Milky Way. As I show below, compared to the Ra, the R5 did well, but could not record the depth of nebulosity the Ra can, to be expected for a stock camera. 

However, bright nebulas will still be good targets for the R5. But if it’s faint nebulosity you are after, both in wide-field Milky Way images and telescopic close-ups, consider getting an R5 “spectrum modified” by a third-party supplier. Or modifying an EOS R.  

This compares identically processed four-minute exposures at ISO 800 with the R5 vs. the red-sensitive Ra. 

EDGE ARTIFACTS and EDGE GLOWS

DSLRs are prone to vignetting along the top and bottom of the frame from shadowing by the upraised mirror and mirror box. Not having a mirror, and a sensor not deeply recessed in the body, largely eliminates this edge vignetting in mirrorless cameras. 

While the Ra shows a very slight vignetting along the bottom of the frame (visible in the example above), the R5 was clean and fully illuminated to the edges, as it should be.

I was also pleased to see the R5 did not exhibit any annoying “amp glows” — dim, often magenta glows at the edge of the frame in long exposures, created by heat emitted from sensor electronics adding infrared (IR) glows to the image. 

I saw noticeable amp glows in the Canon R6 which could only be eliminated by taking LENR dark frames. It’s a flaw that has yet to be eliminated with firmware updates. Taking LENR darks is not required with the R5, except to reduce thermal hot pixels as noted above.

With a lack of IR amp glows, the R5 should work well when filter-modified to record either more visible Hydrogen-alpha red light, or deeper into the infrared spectrum. 


Resolution — Nightscapes 

Now we come to the very reason to get an R5, its high resolution. Is the difference visible in typical astrophotos? In a word, yes. If you look closely. 

If people only see your photos on Facebook or Instagram, no one will ever see any improvement in your images! But if your photos are seen as large prints, or you are simply a stickler for detail, then you will be happy with the R5’s 45 megapixels. (Indeed, you might wish to wait for the rumoured even higher megapixel Canon 5S!)

This compares identically processed four-minute exposures at ISO 800 with the R5 vs. the red-sensitive Ra. 

Nightscapes, and indeed all landscape photos by day or by night, is where you will see the benefit of more megapixels. Finer details in the foreground show up better. Images are less pixelated. In test images with all three cameras, the R5 did provide sharper images to be sure. But you do have to zoom in a lot to appreciate the improvement. 


Resolution — lunar imaging

This compares blow-ups of images of the Moon taken through a 5-inch f/6 refractor (780mm focal length) with the R6 and R5. 

The Moon through a telescope is another good test of resolution. The above comparison shows how the R5’s smaller 4.4-micron pixels do provide much sharper details and less pixelation than the R6. 

Of course, one could shoot at an even longer focal length to increase the “plate scale” with the R6. But at that same longer focal length the R5 will still provide better resolution, up to the point where its pixels are sampling more than what the atmospheric seeing conditions permit to be resolved. For lunar and planetary imaging, smaller pixels are always preferred, as they allow you to reach the seeing limit with shorter and often faster optical systems. 


Resolution — deep sky

This compares extreme blow-ups of images of the North America Nebula used for the other tests, shot with a 94mm f/4.5 refractor with the three cameras.

On starfields, the difference is not so marked. As I showed in my review of the R6, with “only” 20 megapixels the R6 can still provide detailed deep-sky images. 

However, in comparing the three cameras above, with images taken at a focal length of 420mm, the R5 does provide sharper stars, with faint stars better recorded, and with less blockiness (i.e. “square stars”) on all the star images. At that focal length the plate scale with the R5 is 2.1 arc seconds per pixel. With the R6 it is 3.2 arc seconds per pixel. 

This is dim green Comet PanSTARRS C/2017 K2, at top, passing above the star clusters IC 4756 at lower left and NGC 6633 at lower right on May 25-26, 2022. This is a stack of ten 5-minute exposures with a William Optics RedCat 51 at f/4.9 and the Canon R5 at ISO 800. 

The R5 is a good choice for shooting open and globular star clusters, or any small targets such as planetary nebulas, especially with shorter focal length telescopes. Bright targets will allow using lower ISOs, mitigating any of the R5’s extra noise. 

With an 800mm focal length telescope, the plate scale with the R5 will be 1.1 arc seconds per pixel, about the limit most seeing conditions will permit resolving. With even longer focal length telescopes, the R5’s small pixels would be oversampling the image, with little gain in resolution, at least for deep-sky subjects. Lunar and planetary imaging can benefit from plate scales of 0.5 arc seconds per pixel or smaller. 


CAN YOU CreatE resolution?

This compares an original R6 image with the same image rescaled 200% in ON1 Resize AI and Topaz Gigapixel AI, and with those three compared to an original R5 image. 

Now, one can argue that today’s AI-driven scaling programs such as ON1 Resize AI and Topaz Gigapixel AI can do a remarkable job up-sizing images while enhancing and sharpening details. Why buy a higher-megapixel camera when you can just sharpen images from a lower-resolution model? 

While these AI programs can work wonders on regular images, I’ve found their machine-learning seems to know little about stars, and can often create unwanted artifacts. 

In scaling up an R6 image by 200%, ON1 Resize AI 2022 made a mess of the stars and sky background. Topaz Gigapixel AI did a much better job, leaving few artifacts. But using it to double the R6 image in pixel count still produced an image that does not look as sharp as an original R5 image, despite the latter having fewer pixels than the upsized R6 image. 

Yes, we are definitely pixel-peeping! But I think this shows that it is better to have the pixels to begin with in the camera, and to not depend on software to generate sharpness and detail. 


VIDEO Resolution 

The R5’s 45-megapixel sensor also makes possible its headline selling point when it was released in 2020: 8K movie recording, with movies sized 8192 x 4320 (DCI standard) or 7680 x 4320 (UHD standard) at 29.97 frames per second, almost IMAX quality.

Where the R6’s major selling point for me was its low-light video capability, the R5’s 8K video prowess was less important. Or so I thought. With testing, I can see it will have its place in astrophotography, especially solar eclipses. 

The R5 offers the options of 8K and 4K movies each in either the wider DCI Digital Cinema standard (8K-D and 4K-D) or more common Ultra-High Definition standard (8K-U and 4K-U), as well as conventional 1080 HD.
This shows the Moon shot with the same 460mm-focal length telescope, with full-width frame grabs from movies shot in 8K, 4K, and 4K Movie Crop modes.

Unlike the original Canon R and Rp, the R5 and R6 can shoot 4K movies sampled from the full width of their sensors, so there is no crop factor in the field of view recorded with any lens. 

However, like the R6, the R5 also offers the option of a Movie Crop mode which samples a 4K movie from the central 4096 (4K-D) or 3840 (4K-U) pixels of the sensor. As I show above, this provides a “zoomed-in” image with no loss of resolution, useful when wide field of view is not so important as is zooming into small targets, such as for lunar and solar movies. 

This compares close-ups of frame grabs of the Moon movies shown in full-frame above, as well as a frame from an R6 movie, to compare resolutions.

So what format produces the best resolution when shooting movies? As I show above, magnified frame grabs of the Moon demonstrate that shooting at 8K provides a much less pixelated and sharper result than either the 4K-Fine HQ (which creates a “High-Quality” 4K movie downsampled from 8K) or a standard 4K movie. 

Shooting a 4K movie with the R6 also produced a similar result to the 4K movies from the R5. The slightly softer image in the R5’s 4K frame can, I think, be attributed more to atmospheric seeing. 


Solar eclipse use

Shooting the highest resolution movies of the Moon will be of prime interest to astrophotographers when the Moon happens to be passing in front of the Sun! 

That will happen along a narrow path that crosses North America on April 8, 2024. Capturing the rare total eclipse of the Sun in 8K video will be a goal of many. At the last total solar eclipse in North America, on August 21, 2017, I was able to shoot it in 4K by using a then state-of-the-art top-end Canon DSLR loaned to me by an IMAX movie production company! 

And who knows, by 2024 we might have 100-megapixel cameras capable of shooting and recording the firehose of data from 12K video! But for now, even 8K can be a challenge.

This compares the R5 at 8K with it in the best quality 4K Fine HQ vs. the R5 and R6 in their 4K Movie Crop modes.

However, do you need to shoot 8K to get sharp Moon, Sun or eclipse movies? The above shows the 8K frame-grab compared to the R5’s best quality full-frame 4K Fine, and the R5’s and R6’s 4K Movie Crop mode that doesn’t resample or bin pixels from the larger sensor to create a 4K movie. The Cropped movies look only slightly softer than the R5 at 8K, with less pixelation than the 4K Fine HQ movie. 

When shooting the Sun or Moon through a telescope or long telephoto lens, the wide field of a full-frame movie might not be required, even to take in the two- or three-degree-wide solar corona around the eclipsed Sun. 

However, if a wide field for the maximum extent of the outer corona, combined with sharp resolution is the goal, then a camera like the Canon R5 capable of shooting 8K movies will be the ticket. 

And 8K will be ideal for wide-angle movies of the passage of the Moon’s shadow during any eclipse, or for moderate fields showing the eclipsed Sun flanked by Jupiter and Venus on April 8, 2024.


Canon CLOG3

This shows the difference (using frame grabs from 4K movies) between shooting in Canon C-Log3 and shooting with normal “in-camera” colour grading. The exposures were the same. 

Like the R6, the R5 offers the option of shooting movies in Canon’s C-Log3 profile, which records internally in 10-bit, preserving more dynamic range in movies, up to 12 stops. The resulting movie looks flat, but when “colour graded” later in post, the movie records much more dynamic range, as I show above. Without C-Log3, the bright sunlit lunar crescent is blown out, as will be the Sun’s inner corona. 

The bright crescent Moon with dim Earthshine is a good practice-run stand-in for the eclipsed Sun with its wide range of brightness from the inner to the outer corona. 

Sample Moon Movies

For the full comparison of the R5 and R6 in my test shoot of the crescent Moon, see this narrated demo movie on Vimeo for the 4K movies, shot in various modes, both full-frame and cropped, with C-Log3 on and off. 

Keep in mind that video compression in the on-line version may make it hard to see the resolution difference between shooting modes. 

A “private link” 10-minute video on Vimeo demonstrating 4K video clips with the R5 and R6.

For a movie of the 8K footage, though downsized to 4K for the Vimeo version (the full sized 8K file was 29 Gigs!), see this sample movie below on Vimeo. 

A “private link” video on Vimeo demonstrating 8K video clips with the R5.


LOw-Light VIDEO 

Like the R6, the R5 can shoot at a dragged shutter speed as slow as 1/8-second. That slow shutter, combined with a fast f/1.4 to f/2 lens, and ISOs as high as 51,200 are the keys to shooting movies of the night sky. 

Especially auroras. Only when auroras get shadow-casting bright can we shoot at the normal 1/30-second shutter speed of movies and at lower ISOs. 

This compares frame grabs of aurora movies shot the same night with the R5 at 8K and 4K with the Canon R6 at 4K, all at ISO 51,200.

I was able to shoot a decent aurora one night from home with both the R5 and R6, and with the same fast TTArtisan 21mm f/1.5 RF lens. The sky and aurora changed in brightness from the time I shot with the R6 first to the R5 later. But even so, the movies serve as a look at how the two cameras perform for real-time aurora movies. 

Auroras are where we need to shoot full-frame, for the maximum field of view, and at high ISOs. The R5’s maximum ISO is 51,200, while the R6 goes up to 204,800, though it is largely unusable at that speed for actual shooting, just for previewing scenes.

As expected, the R6 was much less noisy than the R5, by about two stops. The R5 is barely usable at ISO 51,200, while the R6 works respectably well at that speed. If auroras get very bright, then slower ISOs can be used, making the R5 a possible camera for low-light use, but it would not be a first choice, unless 8K auroras are a must-have. 

 Sample aurora Movies

For a narrated movie comparing the R5 and R6 at 4K on the aurora, stepping both through a range of ISO speeds, see this movie at Vimeo.

A “private link” video on Vimeo demonstrating 4K aurora clips with the R5 and R6.

For a movie showing the same aurora shot with the R5 at 8K, see this movie. However, it has been down-sized to 4K for on-line viewing, so you’ll see little difference between it and the 4K footage. Shooting at 8K did not improve or smooth noise performance. 

A “private link” video on Vimeo demonstrating 8K aurora clips with the R5.


BATTERY LIFE — Stills and video

Canon’s new LP-E6NH battery supports charging through the USB-C port and has a higher 2130mAh capacity than the 1800mAh LP-E6 batteries. However, the R5 is compatible with the older batteries.

Like the R6, the R5 comes with a new version of Canon’s standard LP-E6 battery, the LP-E6NH. 

On mild nights, I found the R5 ran fine on one battery for the 3 to 4 hours needed to shoot a time-lapse sequence, or set of deep-sky images, with power to spare. Now, that was with the camera in “Airplane Mode,” which I always use regardless, to turn off the power-consuming WiFi and Bluetooth, which I never use on cameras.

As I noted with the R6, for demanding applications, especially in winter, the R5 can be powered by an outboard USB power bank that has Power Delivery or “PD” capability.

The exception for battery use is when shooting videos, especially 8K. That can drain a battery after an hour of recording, though it takes only 10 to 12 minutes of 8K footage to fill a 128 gigabyte card. While less than half that length will be needed to capture any upcoming total eclipse from diamond ring to diamond ring, the result is still a massive file.


OVERHEATING

More critically, the R5 is also infamous for overheating and shutting down when shooting 8K movies, after a time that depends on how hot the environment is. I found the R5 shot 8K or 4K Fine HQ for about 22 minutes at room temperature before the overheat warning first came on, then shut off recording two or three minutes later. Movie recording cannot continue until the R5 cools off sufficiently, which takes at least 10 to 15 minutes. 

That deficiency might befoul unwary eclipse photographers in 2024. The answer for “no-worry” 8K video recording is the Canon R5C, the video-centric version of the R5, with a built-in cooling fan. 


Features and usability

While certainly not designed with astrophotography in mind, the R5 has several hardware and firmware features that are astrophoto friendly. 

The R5’s Canon-standard flip screen

Like all Canon cameras made in the last few years, the R5 has Canon’s standard articulated screen, which can be angled up for convenient viewing when on a telescope. It is also a full touch screen, with all important camera settings and menus adjustable on screen, good for use at night. 

With 2.1 million dots, the R5’s rear screen has a higher resolution than the 1.62-million-dot screen of the R6, and much higher than the 1 million pixels of the Rp’s screen, but is the same resolution as in the R and Ra. 

The R5’s top-mounted backlit LCD screen

The R5, like the original R, has a top backlit LCD screen for display of current camera settings, battery level and Bulb timer. The lack of a top screen was one of my criticisms of the R6. 

Yes, the hardware Mode dial of the R6 and Rp does make it easier to switch shooting modes, such as quickly changing from Stills to Movie. However, for astrophotography the top screen provides useful information during long exposures, and is handy to check when the camera is on a telescope or tripod aimed up to the sky, without spoiling dark adaptation. I prefer to have one. 

The R5’s front-mounted N3-style remote port

The R5’s remote shutter port, used for connecting external intervalometers or time-lapse motion controllers, is Canon’s professional-grade three-pronged N3 connector. It’s sturdier than the 2.5mm mini-phono plug used by the Rp, R and R6. It’s a plus for the R5. 

As with all new cameras, the R5’s USB port is a USB-C type. A USB-C cable is included.

The R5’s back panel buttons and controls

Like the R6, the R5 has a dedicated magnification button on the back panel for zooming in when manually focusing or inspecting images. In the R and Ra, that button is only on the touch panel rear screen, where it has to be called up by paging to that screen, an inconvenience. While virtual buttons on a screen are easier to see and operate at night than physical buttons, I find a real Zoom button handy as it’s always there.

The R5’s twin cards, a CFexpress Type B and an SD UHS-II 

To handle the high data rates of 8K video and also 4K video when set to the high frame rate option of 120 fps, one of the R5’s memory card slots requires a CFexpress Type B card, a very fast but more costly format. 

As I had no card reader for this format, I had to download movies via a USB cable directly from the camera to my computer, using Canon’s EOS Utility software, as Adobe Downloader out of Adobe Bridge refused to do the job. Plan to buy a card reader.

Allocating memory card use

In the menus, you can choose to record video only to the CFexpress, and stills only to the SD card, or both stills and movies to each card for a backup, with the limitation that 8K and 4K 120fps won’t record to the SD card, even very fast ones. 


FIRMWARE FEATURES

Setting the Interval Timer

Unlike the Canon R and Ra (which both annoyingly lack a built-in intervalometer), but like the R6, the R5 has an Interval Timer in its firmware. This can be used to set up a time-lapse sequence, but with exposures only up to the maximum of 30 seconds allowed by the camera’s shutter speed settings, true of most in-camera intervalometers. Even so, this is a useful function for simple time-lapses.

Setting the Bulb Timer

As with most recent Canon DSLRs and DSLMs, the R5 also includes a built-in Bulb Timer. This allows setting an exposure of any length (many minutes or hours) when the camera is in Bulb mode. However, it cannot be combined with the Interval Timer for multiple exposures; it is good only for single shots. Nevertheless, I find it useful for shooting long exposures for the ground component of nightscape scenes. 

Custom button functions

While Canon cameras don’t have Custom Function buttons per se (unlike Sonys), the R5’s various buttons and dials can be custom programmed to functions other than their default assignments. I assign the * button to turning on and off the Focus Peaking display and, as shown, the AF Point button to a feature only available as a custom function, one that temporarily brightens the rear screen to full, good for quickly checking framing at night. 

Assigning Audio Memos to the Rate button

A handy feature of the R5 is the ability to add an audio notation to images. You shoot the image, play it back, then use the Rate button (if so assigned) to record a voice memo of up to 30 seconds, handy for making notes in the field about an image or a shoot. The audio notes are saved as WAV files with the same file number as the image. 

The infamous Release Shutter Without Lens command

Like other EOS R cameras, the R5 has this notorious “feature” that trips up every new user who attaches their Canon camera to a telescope or manual lens, only to find the shutter suddenly doesn’t work. The answer is to turn ON “Release Shutter w/o Lens” found buried under Custom Functions Menu 4. Problem solved! 

OTHER FEATURES

I provide more details of other features and settings of the R5, many of which are common to the R6, in my review of the R6 here

Multi-segment panoramas with the R5, like this aurora scene, yield superb resolution but can become massive in size, pressing the ability of software and hardware to process them. 

CONCLUSION

No question, the Canon R5 is costly. Most buyers would need to have very good daytime uses to justify its purchase, with astrophotography a secondary purpose. 

That said, other than low-light night sky videos, the R5 does work very well for all forms of astrophotography, providing a level of resolution that lesser cameras simply cannot. 

Nevertheless, if it is just deep-sky imaging that is of interest, then you might be better served with a dedicated cooled-sensor CMOS camera, such as one of the popular ZWO models, and the various accessories that need to accompany such a camera. 

But for me, when it came time to buy another premium camera, I still preferred to have a model that could be used easily, without computers, for many types of astro-images, particularly nightscapes, tracked wide-angle starfields, as well as telescopic images. 

Since buying the R5, after first suspecting it would prove too noisy to be practical, it has in fact become my most used camera, at least for all images where the enhanced red sensitivity of the EOS Ra is not required. But for low-light night videos, the R6 is the winner.

However, to make use of the R5’s resolution, you do have to match it with sharp, high-quality lenses and telescope optics, and have the computing power to handle its large files, especially when stitching or stacking lots of them. The R5 can be just the start of a costly spending spree! 

— Alan, June 23, 2022 / © 2022 Alan Dyer / AmazingSky.com  


Testing the Canon R6 for Astrophotography


In an extensive technical blog, I put the Canon R6 mirrorless camera through its paces for the demands of astrophotography. 

Every major camera manufacturer, with the lone exception of stalwart Pentax, has moved from producing digital lens reflex (DSLR) cameras, to digital single lens mirrorless (DSLM) cameras. The reflex mirror is gone, allowing for a more compact camera, better movie capabilities, and enhanced auto-focus functions, among other benefits. 

But what about for astrophotography? I reviewed the Sony a7III and Nikon Z6 mirrorless cameras here on my blog and, except for a couple of points, found them excellent for the demands of most astrophotography. 

For the last two years I’ve primarily used Canon’s astro-friendly and red-sensitive EOS Ra mirrorless, a model sadly discontinued in September 2021 after just two years on the market. I reviewed that camera in the April 2020 issue of Sky & Telescope magazine, with a quick first look here on my blog

The superb performance of the Ra has prompted me to stay with the Canon mirrorless R system for future camera purchases. Here I test the mid-priced R6, introduced in August 2020.

CLICK or TAP on an image to bring it up full screen for closer inspection. All images are © 2021 by Alan Dyer/AmazingSky.com. Use without permission is prohibited.

M31, the spiral galaxy in Andromeda, with the Canon R6 mirrorless camera. It is a stack of 8 x 8-minute exposures at ISO 800, blended with a stack of 8 x 2-minute exposures at ISO 400 for the core, to prevent it from overexposing too much, all with a SharpStar 76mm apo refractor at f/4.5 with its field flattener/reducer.

TL;DR SUMMARY

The Canon R6 has proven excellent for astrophotography, exhibiting better dynamic range and shadow recovery than most Canon DSLRs, due to the ISO invariant design of the R6 sensor. It is on par with the low-light performance of Nikon and Sony mirrorless cameras. 

The preview image is sensitive enough to allow easy framing and focusing at night. The movie mode produces usable quality up to ISO 51,200, making 4K movies of auroras possible. Canon DSLRs cannot do this. 

Marring the superb performance are annoying deficiencies in the design, and one flaw in the image quality – an amp glow – that particularly impacts deep-sky imaging.

R6 pros

The Canon R6 is superb for its:

  • Low noise, though not exceptionally so
  • ISO invariant sensor performance for good shadow recovery 
  • Sensitive live view display with ultra-high ISO boost in Movie mode 
  • Relatively low noise Movie mode with full frame 4K video
  • Low light auto focus and accurate manual focus assist  
  • Good battery life 

R6 cons

The Canon R6 is not so superb for its:

Design Deficiencies 

  • Lack of a top LCD screen
  • Bright timer display in Bulb on the rear screen
  • No battery level indication when shooting 
  • Low grade R3-style remote jack, same as on entry-level Canon DSLRs 

Image Quality Flaw

  • Magenta edge “amp glow” in long exposures 
The Canon Ra on the left with the 28-70mm f/2 RF lens and the Canon R6 on the right with the 70-200mm f/2/8 RF lens, two superb but costly zooms for the R system cameras.

CHOOSING THE R6

Canon’s first full-frame mirrorless camera, the 30-megapixel EOS R, was introduced in late 2018 to compete with Sony. As of late-2021 the main choices in a Canon DSLM for astrophotography are either the original R, the 20-megapixel R6, the 26-megapixel Rp, or the 45-megapixel R5. 

The new 24-megapixel Canon R3, while it has impressive low-noise performance, is designed primarily for high-speed sports and news photography. It is difficult to justify its $6,000 cost for astro work. 

I have not tested Canon’s entry-level, but full-frame Rp. While the Rp’s image quality is likely quite good, its small battery and short lifetime on a single charge will be limiting factors for astrophotography. 

Nor have I tested the higher-end R5. Friends who use the R5 for nightscape work love it, but with smaller pixels the R5 will be noisier than the R6, which lab tests at sites such as DPReview.com seem to confirm. 

Meanwhile, the original EOS R, while having excellent image quality and features, is surely destined for replacement in the near future – with a Canon EOS R Mark II? The R’s successor might be a great astrophoto camera, but with the Ra gone, I feel the R6 is currently the prime choice from Canon, especially for nightscapes.

I tested an R6 purchased in June 2021 and updated in August with firmware v1.4. I’ll go through its performance and functions with astrophotography in mind. I’ve ignored praised R6 features such as eye tracking autofocus, in-body image stabilization, and high speed burst rates. They are of limited or no value for astrophotography. 

Along the way, I also offer a selection of user tips, some of which are applicable to other cameras. 

LIVE VIEW FOCUSING AND FRAMING

“Back-of-the-camera” views of the R6 in its normal Live View mode (upper left) and its highly-sensitive Movie Mode (upper right), compared to views with four other cameras. Note the Milky Way visible with the R6 in its Movie mode, similar to the Sony in Bright Monitoring mode.

The first difference you will see when using any new mirrorless camera, compared to even a high-end DSLR, is how much brighter the “Live View” image is when shooting at night. DSLM cameras are always in Live View – even the eye-level viewfinder presents a digital image supplied by the sensor. 

As such, whether on the rear screen on in the viewfinder, you see an image that closely matches the photo you are about to take, because it is the image you are about to take. 

To a limit. DSLMs can do only so much to simulate what a long 30-second exposure will look like. But the R6, like many DSLMs, goes a long way in providing a preview image bright enough to frame a dark scene and focus on bright stars. Turn on Exposure Simulation to brighten the live image, and open the lens as wide as possible. 

The Canon R6 in its Movie Mode at ISO 204,800 and with a lens wide open.

But the R6 has a trick up its sleeve for framing nightscapes. Switch the Mode dial to Movie, and set the ISO up to 204,800 (or at night just dial in Auto ISO), and with the lens wide open and shutter on 1/8 second (as above), the preview image will brighten enough to show the Milky Way and dark foreground, albeit in a noisy image. But it’s just for aiming and framing.

This is similar to the excellent, but well-hidden Bright Monitoring mode on Sony Alphas. This high-ISO Movie mode makes it a pleasure using the R6 for nightscapes. The EOS R and Ra do not have this ability. While their live view screens are good, they are not as sensitive as the R6’s, with the R and Ra’s Movie modes able to go up to only ISO 12,800. The R5 can go up to “only” ISO 51,200 in its Movie mode, good but not quite high enough for live framing on dark nights. 

Comparing Manual vs. Auto Focus results with the R6.

The R6 will also autofocus down to a claimed EV -6.5, allowing it to focus in dim light for nightscapes, a feat impossible in most cameras. In practice with the Canon RF 15-35mm lens at f/2.8, I found the R6 can’t autofocus on the actual dark landscape, but it can autofocus on bright stars and planets (provided, of course, the camera is fitted with an autofocus lens). 

Autofocusing on bright stars proved very accurate. By comparison, while the Ra can autofocus on distant bright lights, it fails on bright stars or planets. 

Turning on Focus Peaking makes stars turn red, yellow or blue (your choice of colours) when they are in focus, as a reassuring confirmation. 

The Focus Peaking and Focus Guide menu.
The R6 live view display with Focus Guide arrows on and focused on a star, Antares.

In manual focus, an additional Focus Aid overlay provides arrows that close up and turn green when in focus on a bright star or planet. Or you can zoom in by 5x or 10x to focus by eye the old way by examining the star image. I wish the R6 had a 15x or 20x magnification; 5x and 10x have long been the Canon standards. Only the Ra offered 30x for ultra-precise focusing on stars. 

In all, the ease of framing and focusing will be the major improvement you’ll enjoy by moving to any mirrorless, especially if your old camera is a cropped-frame Canon Rebel or T3i! But the R6 particularly excels at ease of focusing and framing. 

NOISE PERFORMANCE

The key camera characteristic for astrophoto use is noise. I feel it is more important than resolution. There’s little point in having lots of fine detail if it is lost in a blizzard of high-ISO noise. And for astro work, we are almost always shooting at high ISOs.

Comparing the R6’s noise at increasingly higher ISO speeds on a starlit nightscape.

With just 20 megapixels, low by today’s standards, the R6 has individual pixels, or more correctly “photosites,” that are each 6.6 microns in size, the “pixel pitch.” 

By comparison, the 30-megapixel R (and Ra) has a pixel pitch of 5.4 microns, the 45-megapixel R5’s pixel pitch is 4.4 microns, while the acclaimed low-light champion in the camera world, the 12-megapixel Sony a7sIII, has large 8.5-micron photosites. 

The bigger the photosites (i.e. the larger the pixel pitch), the more photons each photosite can collect in a given amount of time – and the more photons they can collect, period, before they overfill and clip highlights. More photons equals more signal, and therefore a better signal-to-noise ratio, while the greater “full-well depth” yields higher dynamic range. 

Each generation of camera also improves the signal-to-noise ratio by suppressing noise via its sensor design and improved signal processing hardware and firmware. The R6 uses Canon’s latest DIGIC X processor shared by the company’s other mirrorless cameras. 

Comparing the R6 noise with the 6D MkII and EOS Ra on a deep-sky subject, galaxies.

In noise tests comparing the R6 against the Ra and Canon 6D Mark II, all three cameras showed a similar level of noise at ISO settings from 400 up to 12,800. But the 6D Mark II performed well only when properly exposed. Both the R6 and Ra performed much better for shadow recovery in underexposed scenes. 

Comparing the R6 noise with with the 6D MkII and EOS Ra on a shadowed nightscape.
Comparing the R6 noise with the EOS Ra on the Andromeda Galaxy at typical deep-sky ISO speeds.

In nightscapes and deep-sky images the R6 and Ra looked nearly identical at each of their ISO settings. This was surprising considering the Ra’s smaller photosites, which perhaps attests to the low noise of the astronomical “a” model. 

Or it could be that the R6 isn’t as low noise as it should be for a 20 megapixel camera. But it is as good as it gets for Canon cameras, and that’s very good indeed.

I saw no “magic ISO” setting where the R6 performed better than at other settings. Noise increased in proportion to the ISO speed. It proved perfectly usable up to ISO 6400, with ISO 12,800 acceptable for stills when necessary. 

ISO INVARIANCY

The flaw in many Canon DSLRs, one documented in my 2017 review of the 6D Mark II, was their poor dynamic range due to the lack of an ISO invariant sensor design. 

The R6, as with Canon’s other R-series cameras, has largely addressed this weakness. The sensor in the R6 appears to be nicely ISO invariant and performs as well as the Sony and Nikon cameras I have used and tested, models praised for their ISO invariant behaviour. 

Where this trait shows itself to advantage is on nightscapes where the starlit foreground is often dark and underexposed. Bringing out detail in the shadows in raw files requires a lot of Shadow Recovery or increasing the Exposure slider. Images from an ISO invariant sensor can withstand the brightening “in post” far better, with minimal noise increase or degradations such as a loss of contrast, added banding, or horrible discolourations. 

Comparing the R6 for ISO Invariancy on a starlit nightscape.

To test the R6, I shot sets of images at the same shutter speed, one well-exposed at a high ISO, then several at successively lower ISOs to underexpose by 1 to 5 stops. I then brightened the underexposed images by increasing the Exposure in Camera Raw by the same 1 to 5 stops. In an ideal ISO invariant sensor, all the images should look the same. 

The R6 did very well in images underexposed by up to 4 stops. Images underexposed by 5 stops started to fall apart, but I’ve seen that in Sony and Nikon images as well. 

Comparing the R6 for ISO Invariancy on a moonlit nightscape.

This behaviour applies to images underexposed by using lower ISOs than what a “normal” exposure might require. Underexposing with lower ISOs can help maintain dynamic range and avoid highlight clipping. But with nightscapes, foregrounds can often be too dark even when shot at an ISO high enough to be suitable for the sky. Foregrounds are almost always underexposed, so good shadow recovery is essential for nightscapes, and especially time-lapses, when blending in separate longer exposures for the ground is not practical.

With its improved ISO invariant sensor, the R6 will be a fine camera for nightscape and time-lapse use, which was not true of the 6D Mark II. 

For those interested in more technical tests and charts, I refer you to DxOMark’s report on the Canon R6.  

Comparing R6 images underexposed in 1-stop increments by using shorter shutter speeds.
Comparing R6 images underexposed in 1-stop increments by using smaller apertures.

However, to be clear, ISO invariant behaviour doesn’t help you as much if you underexpose by using too short a shutter speed or too small a lens aperture. I tested the R6 in series of images underexposed by keeping ISO the same but decreasing the shutter speed then the aperture in one-stop increments. 

The underexposed images fell apart in quality much sooner, when underexposed more than 3 stops. Again, this is behaviour similar to what I’ve seen in Sonys and Nikons. For the best image quality I feel it is always a best practice to expose well at the camera. Don’t count on saving images in post. 

An in-camera image fairly well exposed with an ETTR histogram.

TIP: Underexposing by using too short an exposure time is the major mistake astrophotographers make, who then wonder why their images are riddled with odd artifacts and patten noise. Always Expose to the Right (ETTR), even with ISO invariant cameras. The best way to avoid noise is to give your sensor more signal, by using longer exposures or wider apertures. Use settings that push the histogram to the right. 

LONG EXPOSURE NOISE REDUCTION

All cameras will exhibit thermal noise in long exposures, especially on warm nights. This form of noise peppers the shadows with hot pixels, often brightly coloured. 

This is not the same as the shot and read noise that adds graininess to high-ISO images and that noise reduction software can smooth out. This is a common misunderstanding, even among professional photographers who should know better! 

Thermal noise is more insidious and harder to eliminate in post without harming the image. However, Monika Deviat offers a clever method here at her website

The standard Canon LENR menu.

Long Exposure Noise Reduction (LENR) eliminates this thermal noise by taking a “dark frame” and subtracting it in-camera to yield a raw file free of hot pixels. 

And yes, LENR does apply to raw files, another fact even many professional photographers don’t realize. It is High ISO Noise Reduction that applies only to JPGs, along with Color Space and Picture Styles.

Comparing a dark nightscape without and with LENR on a warm night. Hot pixels are mostly gone at right.

The LENR option on the R6 did eliminate most hot pixels, though sometimes still left, or added, a few. LENR is needed more on warm nights, and with longer exposures at higher ISOs. So the extent of thermal noise in any camera can vary a lot from shoot to shoot.

When LENR is active, the R6’s rear screen lights up with “Busy,” which is annoyingly bright. To hide this display, the only option is to close the screen. 

As with the EOS Ra, and all mirrorless cameras, the R6 has no “dark frame buffer” that allows several exposures to be taken in quick succession even with LENR on. Canon’s full-frame DSLRs have this little-known buffer that allows 3, 4, or 5 “light frames” to be taken in a row before the LENR dark frame kicks in a locks up the camera on Busy. 

Comparing long exposure images with the lens cap on (dark frames), to show just thermal noise. The right edge of the frame is shown, blown up, to reveal the amp glow, which LENR removes.

With all Canon R cameras, and most other DSLRs, turning on LENR forces the camera to take a dark frame after every light frame, doubling the time it takes to finish every exposure. That’s a price many photographers aren’t willing to pay, but on warm nights it can be necessary, and a best practice, for the reward of cleaner images.

The standard Canon Sensor Cleaning menu.

TIP: If you find hot pixels are becoming more obvious over time, try this trick: turn on the Clean Manually routine for 30 seconds to a minute. In some cameras this can remap the hot pixels so the camera can better eliminate them.  

STAR QUALITY 

Using LENR with the R6 did not introduce any oddities such as oddly-coloured, green or wiped-out stars. Even without LENR I saw no evidence of green stars, a flaw that plagues some Sony cameras at all times, or Nikons when using LENR. 

Comparing the R6 for noise and star colours at typical deep-sky ISOs and exposure times.

Canons have always been known for their good star colours, and the R6 is no exception. According to DPReview the R6 has a low-pass anti-alias filter in front of its sensor. Cameras which lack such a sensor filter do produce sharper images, but stars that occupy only one or two pixels might not de-Bayer properly into the correct colours. That’s not an issue with the R6.

I also saw no “star-eating,” a flaw Nikons and Sonys have been accused of over the years, due to aggressive in-camera noise reduction even on raw files. Canons have always escaped charges of star-eating. 

VIGNETTING/SHADOWING

DSLRs are prone to vignetting along the top and bottom of the frame from shadowing by the upraised mirror and mirror box. Not having a mirror, and a sensor not deeply recessed in the body, largely eliminates this edge vignetting in mirrorless cameras. 

This illustrates the lack of edge shadows but magenta edge glows in a single Raw file boosted for contrast.

That is certainly true of the R6. Images boosted a lot in contrast, as we do with deep-sky photos, show not the slightest trace of vignetting along the top or bottom edges There were no odd clips or metal bits intruding into the light path, unlike in the Sony a7III I tested in 2018. 

The full frame of the R6 can be used without need for cropping or ad hoc edge brightening in post. Except …

EDGE ARTIFACTS/AMP GLOWS

The R6 did exhibit one serious and annoying flaw in long-exposure high-ISO images – a magenta glow along the edges, especially the right edge and lower right corner. 

Comparing a close-up of a nightscape, without and with LENR, to show the edge glow gone with LENR on.

Whether this is the true cause or not, it looks like “amplifier glow,” an effect caused by heat from circuitry illuminating the sensor with infra-red light. It shows itself when images are boosted in contrast and brightness in processing. It’s the sort of flaw revealed only when testing for the demands of astrophotography. It was present in images I took through a telescope, so it is not IR leakage from an auto-focus lens. 

I saw this type of amp glow with the Sony a7III, a flaw eventually eliminated in a firmware update that, I presume, turned off unneeded electronics in long exposures. 

Amp glow is something I have not seen in Canon cameras for many years. In a premium camera like the R6 it should not be there. Period. Canon needs to fix this with a firmware update.

UPDATE AUGUST 1, 2022: As of v1.6 of the R6 firmware, released in July 2022, the amp glow issue remains and has not been fixed. It may never be at this point.

It is the R6’s only serious image flaw, but it’s surprising to see it at all. Turning on LENR eliminates the amp glow, as it should, but using LENR is not always practical, such as in time-lapses and star trails.

For deep-sky photography high-ISO images are pushed to extremes of contrast, revealing any non-uniform illumination or colour. The usual practice of taking and applying calibration dark frames should also eliminate the amp glow. But I’d rather it not be there in the first place!

RED SENSITIVITY

The R6 I bought was a stock “off-the-shelf” model. It is Canon’s now-discontinued EOS Ra model that is (or was) “filter-modified” to record a greater level of the deep red wavelength from red nebulas in the Milky Way. Compared to the Ra, the R6 did well, but could not record the depth of nebulosity the Ra can, to be expected for a stock camera. 

Comparing the stock R6 with the filter-modified Ra on Cygnus nebulosity.

In wide-field images of the Milky Way, the R6 picked up a respectable level of red nebulosity, especially when shooting through a broadband light pollution reduction filter, and with careful processing. 

Comparing the stock R6 with the filter-modified Ra on the Swan Nebula with a telescope with minimal processing to the Raw images.
Comparing the stock R6 with the filter-modified Ra on the Swan Nebula with a telescope with a dual narrowband filter and with colour correction applied to the single Raw images.

However, when going after faint nebulas through a telescope, even the use of a narrowband filter did not help bring out the target. Indeed, attempting to correct the extreme colour shift introduced by such a filter resulted in a muddy mess and accentuated edge glows with the R6, but worked well with the Ra. 

While the R6 could be modified by a third party, the edge amp glow might spoil images, as a filter modification can make a sensor even more sensitive to IR light, potentially flooding the image with unwanted glows. 

TIP: Buying a used Canon Ra (if you can find one) might be one choice for a filter-modified mirrorless camera, one much cheaper than a full frame cooled CMOS camera such as a ZWO ASI2400MC. Or Spencer’s Camera sells modified versions of all the R series cameras with a choice of sensor filters. But I have not used any of their modded cameras.

RESOLUTION 

A concern of prospective buyers is whether the R6’s relatively low 20-megapixel sensor will be sharp enough for their purposes. R6 images are 5472 by 3648 pixels, much less than the 8000+ pixel-wide images from high-resolution cameras like the Canon R5, Nikon Z7II or Sony a1.

Unless you sell your astrophotos as very large prints, I’d say don’t worry. In comparisons with the 30-megapixel Ra I found it difficult to see a difference in resolution between the two cameras. Stars were nearly as well resolved in the R6, and only under the highest pixel-peeping magnification did stars look a bit more pixelated in the R6 than in the Ra. Faint stars were equally well recorded. 

Comparing resolution of the R6 vs. Ra with a blow-up of wide-field 85mm images
Comparing resolution of the R6 vs. Ra on blow-ups of the Andromeda Galaxy with a 76mm apo refractor. The R6 is more pixellated but it takes pixel peeping to see it!

The difference between 20 and 30 megapixels is not as great as you might think for arc-second-per-pixel plate scale. I think it would take going to the R5 with its 45 megapixel sensor to provide enough of a difference in resolution over the R6 to be obvious in nightscape scenes, or when shooting small, detailed deep-sky subjects such as globular clusters. 

If landscape or wildlife photography by day is your passion, with astrophotography a secondary purpose, then the more costly but highly regarded R5 might be the better choice. 

Super Resolution menu in Adobe Lightroom.

TIP: Adobe now offers (in Lightroom and in Camera Raw) a Super Resolution option, that users might think (judging by the rave reviews on-line) would be the answer to adding resolution to astro images from “low-res” cameras like the R6. 

Comparing a normal R6 image with the same image upscaled with Super Resolution.

Sorry! In my tests on astrophotos I’ve found Super Resolution results unsatisfactory. Yes, stars were less pixelated, but they became oddly coloured in the AI-driven up-scaling. Green stars appeared! The sky background also became mottled and uneven. 

I would not count on such “smart upscaling” options to add more pixels to astro-images from the R6. Then again, I don’t think there’s a need to. 

RAW vs. cRAW

Canon now offers the option of shooting either RAW or cRAW files, the latter being the same megapixel count but compressed in file size by almost a factor of two. This allows shooting twice as many images before card space runs out, perhaps useful for shooting lots of time-lapses on extended trips away from a computer. 

The R6 Image Quality menu with the cRAW Option.
Comparing an R6 cRAW with a RAW image.

However, the compression is not lossless. In high-ISO test images purposely underexposed, then brightened in post, I could see a slight degradation in cRAW images – the noise background looked less uniform and exhibited a blocky look, like JPG artifacts. 

The R6’s dual SD card slots.

TIP: With two SD card slots in the R6 (the second card can be set to record either a backup of images on card one, or serve as an overflow card) and the economy of large SD cards, there’s not the need to conserve card space as there once was. I would suggest always shooting in the full RAW format. Why accept any compression and loss of image quality? 

BATTERY LIFE

The R6 uses a new version of Canon’s standard LP-E6 battery, the LP-E6NH, that supports charging through the USB-C port and has a higher 2130mAh capacity than the 1800mAh LP-E6 batteries. However, the R6 is compatible with older batteries.

On warm nights, I found the R6 ran fine on one battery for the 3 to 4 hours needed to shoot a time-lapse sequence, with power to spare. However, as noted below, the lack of a top LCD screen means there’s no ongoing display of battery level, a deficiency for time-lapse and deep-sky work. 

For demanding applications, especially in winter, the R6 can be powered by an outboard USB power bank that has “Power Delivery” capability. That’s a handy feature. There’s no need to install a dummy battery leading out to a specialized power source. 

The R6’s Connection menu with Airplane mode to turn off battery-eating WiFi and Bluetooth.

TIP: Putting the camera into Airplane mode (to turn off WiFi and Bluetooth), turning off the viewfinder, and either switching off or closing the rear screen all helps conserve power. The R6 does not have GPS built in. Tagging images with location data requires connecting to your phone.

VIDEO USE

A major selling point for me was the R6’s low-light video capability. It replaces my Sony A7III, which had been my “go to” camera for real-time 4K movies of auroras. 

As best I can tell (from the dimmer auroras I’ve shot to date), the R6 performs equally as well as the Sony. It is able to record good quality (i.e. acceptably noise-free) 4K movies at ISO 25,600 to ISO 51,200. While it can shoot at up to ISO 204,800, the excessive noise makes the top ISO an emergency-use only setting. 

The R6’s Movie size and quality options, with 4K and Full HD formats and frame rates.
Comparing the R6 on a dim aurora at various high ISO speeds. Narrated at the camera — excuse the wind noise! Switch to HD mode for the best video playback quality. This was shot in 4K but WordPress plays back only in HD.

The R6 can shoot at a dragged shutter speed as slow as 1/8-second – good, though not as slow as the Sony’s 1/4-second slowest shutter speed in movie mode. That 1/8-second shutter speed and a fast f/1.4 to f/2 lens are the keys to shooting movies of the night sky. Only when auroras get shadow-casting bright can we shoot at the normal 1/30-second shutter speed and at lower ISOs.

As with Nikons (but not Sonys), the Canon R6 saves its movie settings separately from its still settings. When switching to Movie mode you don’t have to re-adjust the ISO, for example, to set it higher than it might have been for stills, very handy for taking both stills and movies of an active aurora, where quick switching is often required. 

Unlike the R and Rp, the R6 captures 4K movies from the full width of the sensor, preserving the field of view of wide-angle lenses. This is excellent for aurora shooting. 

The R6’s Movie Cropping menu option
A 4K movie of the Moon in full-frame and copped-frame modes, narrated at the camera. Again, this was shot in 4K but WordPress plays back only in HD.
Comparing blow-ups of frame-grabbed stills from a full-frame 4K vs. Cropped frame 4K. The latter is less pixellated.

However, the R6 offers the option of a “Movie Crop” mode. Rather than taking the 4K movie downsampled from the entire sensor, this crop mode records from a central 1:1 sampled area of the sensor. That mode can be useful for high-magnification lunar and planetary imaging, for ensuring no loss of resolution. It worked well, producing videos with less pixelated fine details in test movies of the Moon. 

Though of course I have yet to test it on one, the R6 should be excellent for movies of total solar eclipses. It can shoot 4K up to 60 frames per second in both full frame and cropped frame. It cannot shoot 6K (buy the R3!) or 8K (buy the R5!). 

The R6’s Canon Log settings menu for video files.

Shooting in the R6’s Canon cLog3 profile records internally in 10-bit, preserving more dynamic range in movies, up to 12 stops. During eclipses, that will be a benefit for recording totality, with the vast range of brightness in the Sun’s corona. It should also aid in shooting auroras which can vary over a huge range in brightness. 

Grading a cLog format movie in Final Cut under Camera LUT.

TIP: Processing cLog movies, which look flat out of camera, requires applying a cLog3 Look Up Table, or LUT, to the movie clips in editing, a step called “colour grading.” This is available from Canon, from third-party vendors or, as it was with my copy of Final Cut Pro, might be already installed in your video editing software. When shooting, turn on View Assist so the preview looks close to what the final graded movie will look like.

EXPOSURE TRACKING IN TIME-LAPSES

In one test, I shot a time-lapse from twilight to darkness with the R6 in Aperture Priority auto-exposure mode, of a fading display of noctilucent clouds. I just let the camera lengthen the shutter speed on its own. It tracked the darkening sky very well, right down to the camera’s maximum exposure time of 30 seconds, using a fish-eye lens at f/2.8. This demonstrated that the light meter in the R6 was sensitive enough to work well in dim light.

Other cameras I have used cannot do this. The meter fails at some point and the exposure stalls at 5 or 6 seconds long, resulting in most frames after that being underexposed. By contrast, the R6 showed excellent performance, negating the need for special bulb ramping intervalometers for some “holy grail” scenes. Here’s the resulting movie.

A time-lapse of 450 frames from 0.4 seconds to 30 seconds, with the R6 in Av mode. Set to 1080P for the best view!
A screenshot from LRTimelapse showing the smoothness of the exposure tracking (the blue line) through the sequence,

In addition, the R6’s exposure meter tracked the darkening sky superbly, with nary a flicker or variation. Again, few cameras can do this. Nikons have an Exposure Smoothing option in their Interval Timers which works well.

The R6 has no such option but doesn’t seem to need it. The exposure did fail at the very end, when the shutter reached its maximum of 30 seconds. If I had the camera on Auto ISO, it might have started to ramp up the ISO to compensate, a test I have yet to try. Even so, this is impressive time-lapse performance in auto-exposure.

MISSING FEATURES

The R6, like the low-end Rp, lacks a top LCD screen for display of camera settings and battery level. In its place we get a traditional Mode dial, which some daytime photographers will prefer. But for astrophotography, a backlit top LCD screen provides useful information during long exposures. 

The R6 top and back of camera view.

Without it, the R6 provides no indication of battery level while a shoot is in progress, for example, during a time-lapse. A top screen is also useful for checking ISO and other settings by looking down at the camera, as is usually the case when it’s on a tripod or telescope. 

The lack of a top screen is an inconvenience for astrophotography. We are forced to rely on looking at the brighter rear screen for all information. It is a flip-out screen, so can be angled up for convenient viewing on a telescope.

The R6’s flip screen, similar to most other new Canon cameras.

The R6 has a remote shutter port for an external intervalometer, or control via a time-lapse motion controller. That’s good! 

However, the port is Canon’s low-grade 2.5mm jack. It works, and is a standard connector, but is not as sturdy as the three-pronged N3-style jack used on Canon’s 5D and 6D DSLRs, and on the R3 and R5. Considering the cost of the R6, I would have expected a better, more durable port. The On/Off switch also seems a bit flimsy and easily breakable under hard use. 

The R6’s side ports, including the remote shutter/intervalometer port.

These deficiencies provide the impression of Canon unnecessarily “cheaping out” on the R6. You can forgive them with the Rp, but not with a semi-professional camera like the R6.

INTERVAL TIMER

Unlike the Canon R and Ra (which still mysteriously lack a built-in interval timer, despite firmware updates), the R6 has one in its firmware. Hurray! This can be used to set up a time-lapse sequence, but on exposures only up to the maximum of 30 seconds allowed by the camera’s shutter speed settings, true of most in-camera intervalometers. 

The Interval Timer menu page.

For 30-second exposures taken in succession as quickly as possible the interval on the R6 has to be set to 34 seconds. The reason is that the 30-second exposure is actually 32 seconds, true of all cameras. With the R6, having a minimum gap in time between shots requires an Interval not of 33 seconds as with some cameras, but 34 seconds. Until you realize this, setting the intervalometer correctly can be confusing. 

Like all Canon cameras, the R6 can be set to take only up to 99 frames, not 999. That seems a dumb deficiency. Almost all time-lapse sequences require at least 200 to 300 frames. What could it possibly take in the firmware to add an extra digit to the menu box? It’s there at in the Time-lapse Movie function that assembles a movie in camera, but not here where the camera shoots and saves individual frames. It’s another example where you just can’t fathom Canon’s software decisions.

Setting the Interval Timer for rapid sequence shots with a 30-second exposure.

TIP: If you want to shoot 100 or more frames, set the Number of Frames to 00, so it will shoot until you tell the camera to stop. But awkwardly, Canon says the way to stop an interval shoot is to turn off the camera! That’s crude, as doing so can force you to refocus if you are using a Canon RF lens. Switching the Mode dial to Bulb will stop an interval shoot, an undocumented feature. 

BULB TIMER

As with most recent Canon DSLRs and DSLMs, the menu also includes a Bulb Timer. This allows setting an exposure of any length (many minutes or hours) when the camera is in Bulb mode. This is handy for single long shots at night. 

The Bulb Timer menu page. Bulb Timer only becomes an active choice when the camera is on Bulb.

However, it cannot be used in conjunction with the Interval Timer to program a series of multi-minute exposures, a pity. Instead, a separate outboard intervalometer has to be used for taking an automatic set of any exposures longer than 30 seconds, true of all Canons. 

In Bulb and Bulb Timer mode, the R6’s rear screen lights up with a bright Timer readout. While the information is useful, the display is too bright at night and cannot be dimmed, nor turned red for night use, exactly when you are likely to use Bulb. The power-saving Eco mode has no effect on this display, precisely when you would want it to dim or turn off displays to prolong battery life, another odd deficiency in Canon’s firmware. 

The Bulb Timer screen active during a Bulb exposure. At night it is bright!

The Timer display can only be turned off by closing the flip-out screen, but now the viewfinder activates with the same display. Either way, a display is on draining power during long exposures. And the Timer readout lacks any indication of battery level, a vital piece of information during long shoots. The Canon R, R3 and R5, with their top LCD screens, do not have this annoying “feature.” 

TIP: End a Bulb Timer shoot prematurely by hitting the Shutter button. That feature is documented. 

IN-CAMERA IMAGE STACKING

The R6 offers a menu option present on many recent Canon cameras: Multiple Exposure. The camera can take and internally stack up to 9 images, stacking them by using either Average (best for reducing noise) or Bright mode (best for star trails). An Additive mode also works for star trails, but stacking 9 images requires reducing the exposure of each image by 3 stops, say from ISO 1600 to ISO 200, as I did in the example below. 

The Multiple Exposure menu page.

The result of the internal stacking is a raw file, with the option of also saving the component raws. While the options work very well, in all the cameras I’ve owned that offer such functions, I’ve never used them. I prefer to do any stacking needed later at the computer. 

Comparing a single image with a stack of 9 exposures with 3 in-camera stacking methods.

TIP: The in-camera image stacking options are good for beginners wanting to get advanced stacking results with a minimum of processing fuss later. Use Average to stack ground images for smoother noise. Use Bright for stacking sky images for star trails. Activate one of those modes, then control the camera with a separate intervalometer to automatically shoot and internally stack several multi-minute exposures. 

SHUTTER OPERATION

Being a mirrorless camera, there is no reflex mirror to introduce vibration, and so no need for a mirror lockup function. The shutter can operate purely mechanically, with physical metal curtains opening and closing to start and end the exposure. 

However, the default “out of the box” setting is Electronic First Curtain, where the actual exposure, even when on Bulb, is initiated electronically, but ended by the mechanical shutter. That’s good for reducing vibration, perhaps when shooting the Moon or planets through a telescope at high magnification. 

R6 Shutter Mode options.

In Mechanical, the physical curtains both start and end the exposure. It’s the mode I usually prefer, as I like to hear the reassuring click of the shutter opening. I’ve never found shutter vibration a problem when shooting deep sky images on a telescope mount of any quality. 

In Mechanical mode the shutter can fire at up to 12 frames a second, or up to 20 frames a second in Electronic mode where both the start and end of the exposure happen without the mechanical shutter. That makes for very quiet operation, good for weddings and golf tournaments! 

Electronic Shutter Mode is for fastest burst rates but has limitations.

Being vibration free, Electronic shutter might be great during total solar eclipses for rapid-fire bursts at second and third contacts when shooting through telescopes. Maximum exposure time is 1/2 second in this mode, more than long enough for capturing fleeting diamond rings.

Longer exposures needed for the corona will require Mechanical or Electronic First Curtain shutter. Combinations of shutter modes, drive rates (single or continuous), and exposure bracketing can all be programmed into the three Custom Function settings (C1, C2 and C3) on the Mode dial, for quick switching at an eclipse. It might not be until April 8, 2024 until I have a chance to test these features. And by then the R6 Mark II will be out! 

TIP: While the R6’s manual doesn’t state it, some reviews mention (including at DPReview) that when the shutter is in fully Electronic mode the R6’s image quality drops from 14-bit to 12-bit, true of most other mirrorless cameras. This reduces dynamic range. I would suggest not using Electronic shutter for most astrophotography, even for exposures under 1/2 second. For longer exposures, it’s a moot point as it cannot be used. 

The menu option that fouls up all astrophotographers using an R-series camera.

TIP: The R6 has the same odd menu item that befuddles many a new R-series owner, found on Camera Settings: Page 4. “Release Shutter w/o Lens” defaults to OFF, which means the camera will not work if it is attached to a manual lens or telescope it cannot connect to electronically. Turn it ON and all will be solved. This is a troublesome menu option that Canon should eliminate or default to ON. 

OTHER MENU FEATURES

The rear screen is fully touch sensitive, allowing all settings to be changed on-screen if desired, as well as by scrolling with the joystick and scroll wheels. I find going back to an older camera without a touchscreen annoying – I keep tapping the screen expecting it to do something! 

The Multi-Function Button brings up an array of 5 settings to adjust. This is ISO.

The little Multi-Function (M-Fn) button is a worth getting used to, as it allows quick access to a choice of five important functions such as ISO, drive mode and exposure compensation. However, the ISO, aperture and shutter speed are all changeable by the three scroll wheels. 

The Q button brings up the Quick Menu for displaying and adjusting key functions.

There’s also the Quick menu activated by the Q button. While the content of the Quick menu screen can’t be edited, it does contain a good array of useful functions, adjustable with a few taps. 

Under Custom settings, the Dials and Buttons can be re-assigned to other functions.

Unlike Sonys, the R6 has no dedicated Custom buttons per se. However, it does offer a good degree of customization of its buttons, by allowing users to re-assign them to other functions they might find more useful than the defaults. For example ….

This shows the AF Point button being re-assigned to the Maximize Screen Brightness (Temporary) command.
  • I’ve taken the AF Point button and assigned it to the Maximize Screen Brightness function, to temporarily boost the rear screen to full brightness for ease of framing. 
  • The AE Lock button I assigned to switch the Focus Peaking indicators on and off, to aid manual focusing when needed. 
  • The Depth of Field Preview button I assigned to switching between the rear screen and viewfinder, through that switch does happen automatically as you put your eye to the viewfinder.
  • The Set button I assigned to turning off the Rear Display, though that doesn’t have any effect when the Bulb Timer readout is running, a nuisance. 

While the physical buttons are not illuminated, having a touch screen makes it less necessary to access buttons in the dark. It’s a pity the conveniently positioned but mostly unused Rate button can’t be re-programmed to more useful functions. It’s a waste of a button. 

Set up the Screen Info as you like it by turning on and off screen pages and deciding what each should show.

TIP: The shooting screens, accessed by the Info button (one you do need to find in the dark!), can be customized to show a little, a lot, or no information, as you prefer. Take the time to set them up to show just the information you need over a minimum of screen pages. 

LENS AND FILTER COMPATIBILITY

The new wider RF mount accepts only Canon and third-party RF lenses. However, all Canon and third-party EF mount lenses (those made for DSLRs) will fit on RF-mount bodies with the aid of the $100 Canon EF-to-RF lens adapter. 

The Canon ER-to-RF lens adapter will be needed to attach R cameras to most telescope camera adapters and Canon T-rings made for older DSLR cameras.

This adapter will be necessary to attach any Canon R camera to a telescope equipped with a standard Canon T-ring. That’s especially true for telescopes with field flatterers where maintaining the standard 55mm distance between the flattener and sensor is critical for optimum optical performance. 

The shallower “flange distance” between lens and sensor in all mirrorless cameras means an additional adapter is needed not just for the mechanical connection to the new style of lens mount, but also for the correct scope-to-sensor spacing. 

The extra spacing provided by a mirrorless camera has the benefit of allowing a filter drawer to be inserted into the light path. Canon offers a $300 lens adapter with slide-in filters, though the choice of filters useful for astronomy that fit Canon’s adapter is limited. AstroHutech offers a few IDAS nebula filters.

Clip-in filters made for the EOS R, such as those offered by Astronomik, will also fit the R6. Though, again, most narrowband filters will not work well with an unmodified camera.

The AstroHutech adapter allows inserting filters into the light path on telescopes.

TIP: Alternatively, AstroHutech also offers its own lens adapter/filter drawer that goes from a Canon EF mount to the RF mount, and accepts standard 52mm or 48mm filters. It is a great way to add interchangeable filters to any telescope when using an R-series camera, while maintaining the correct back-focus spacing. I use an AstroHutech drawer with my Ra, where the modified camera works very well with narrowband filters. Using such filters with a stock R6 won’t be as worthwhile, as I showed above. 

A trio of Canon RF zooms — all superb but quite costly.

As of this writing, the selection of third-party lenses for the Canon RF mount is limited, as neither Canon or Nikon have “opened up” their system to other lens makers, unlike Sony with their E-mount system. For example, we have yet to see much-anticipated RF-mount lenses from Sigma, Tamron and Tokina. 

A trio of third party RF lenses — L to R: the TTArtisan 7.5mm f/2 and 11mm f/2.8 fish-eyes and the Samyang/Rokinon AF 85mm f/1.4.

Samyang offers 14mm and 85mm auto-focus RF lenses, but now only under their Rokinon branding. I tested the Samyang RF 85mm f/1.4 here at AstroGearToday

The few third-party lenses that are available, from TTArtisan, Venus Optics and other boutique Chinese lens companies, are usually manual focus lenses with reverse-engineered RF mounts offering no electrical contact with the camera. Some of these wide-angle lenses are quite good and affordable. (I tested the TTArtisan 11mm fish-eye here.)

Until other lens makers are “allowed in,” if you want lenses with auto-focus and camera metadata connections, you almost have to buy Canon. Their RF lenses are superb, surpassing the quality of their older EF-mount equivalents. But they are costly. I sold off a lot of my older lenses and cameras to help pay for the new Canon glass! 

I also have reviews of the superb Canon RF 15-35mm f/2.8, as well as the unique Canon RF 28-70mm f/2 and popular Canon RF 70-200mm f/2.8 lenses (a trio making up the  “holy trinity” of zooms) at AstroGearToday.com.

CONTROL COMPATIBILITY 

Astrophotographers often like to operate their cameras at the telescope using computers running specialized control software. I tested the R6 with two popular Windows programs for controlling DSLR and now mirrorless cameras, BackyardEOS (v3.2.2) and AstroPhotographyTool (v3.88). Both recognized and connected to the R6 via its USB port. 

Both programs recognized the Canon R6.

Another popular option is the ASIair WiFi controller from ZWO. It controls cameras via one of the ASIair’s USB ports, and not (confusingly) through the Air’s remote shutter jack marked DSLR. Under version 1.7 of its mobile app, the ASIair now controls Canon R cameras and connected to the R6 just fine, allowing images to be saved both to the camera and to the Air’s own MicroSD card. 

With an update in 2021, the ZWO ASIair now operates Canon R-series cameras.

The ASIair is an excellent solution for both camera control and autoguiding, with operation via a mobile device that is easier to use and power in the field than a laptop. I’ve not tried other hardware and software controllers with the R6. 

TIP: While the R6, like many Canon cameras, can be controlled remotely with a smartphone via the CanonConnect mobile app, the connection process is complex and the connection can be unreliable. The Canon app offers no redeeming features for astrophotography, and maintaining the connection via WiFi or Bluetooth consumes battery power. 

A dim red and green aurora from Dinosaur Provincial Park, Alberta, on August 29/30, 2021. This is a stack of 4 exposures for the ground to smooth noise and one exposure for the sky, all 30 seconds at f/2.8 with the Canon 15-35mm RF lens at 25mm and the Canon R6 at ISO 4000.

SUGGESTIONS TO CANON

To summarize, in firmware updates, Canon should:

  • Fix the low-level amp glow. No camera should have amp glow. 
  • Allow either dimming the Timer readout, turning it red, or just turning it off!
  • Add a battery display to the Timer readout. 
  • Expand the Interval Timer to allow up to 999 frames, as in the Time-Lapse Movie. 
  • Allow the Rate button to be re-assigned to more functions.
  • Default the Release Shutter w/o Lens function to ON.
  • Revise the manual to correctly describe how to stop an Interval Timer shoot.
  • Allow programming multiple long exposures by combining Interval and Bulb Timer, or by expanding the shutter speed range to longer than 30 seconds, as some Nikons can do.
The Zodiacal Light in the dawn sky, September 14, 2021, from home in Alberta, with the winter sky rising. This is a stack of 4 x 30-second exposures for the ground to smooth noise, and a single 30-second exposure for the sky, all with the TTArtisan 7.5mm fish-eye lens at f/2 and on the Canon R6 at ISO 1600.

CONCLUSION

The extended red sensitivity of the Canon EOS Ra makes it better suited for deep-sky imaging. But with it now out of production (Canon traditionally never kept its astronomical “a” cameras in production for more than two years), I think the R6 is now Canon’s best camera (mirrorless or DSLR) for all types of astrophotography, both stills and movies. 

However, I cannot say how well it will work when filter-modified by a third-party. But such a modification is necessary only for recording red nebulas in the Milky Way. It is not needed for other celestial targets and forms of astrophotography. 

A composite showing about three dozen Perseid meteors accumulated over 3 hours of time, compressed into one image showing the radiant point of the meteor shower in Perseus. All frames were with the Canon R6 at ISO 6400 and with the TTArtisan 11mm fish-eye lens at f/2.8.

The low noise and ISO invariant sensor of the R6 makes it superb for nightscapes, apart from the nagging amp glow. That glow will also add an annoying edge gradient to deep-sky images, best dealt with when shooting by the use of LENR or dark frames. 

As the image of the Andromeda Galaxy, M31, at the top of the blog attests, with careful processing it is certainly possible to get fine deep-sky images with the R6. 

For low-light movies the R6 is Canon’s answer to the Sony alphas. No other Canon camera can do night sky movies as well as the R6. For me, it was the prime feature that made the R6 the camera of choice to complement the Ra. 

Alan, September 22, 2021 / © 2021 Alan Dyer / AmazingSky.com  

How to Photograph the Great Conjunction


On December 21 we have a chance to see and shoot a celestial event that no one has seen since the year 1226. 

As Jupiter and Saturn each orbit the Sun, Jupiter catches up to slower moving Saturn and passes it every 20 years. For a few days the two giant planets appear close together in our sky. The last time this happened was in 2000, but with the planets too close to the Sun to see. 

Back on February 18, 1961 the two planets appeared within 14 arc minutes or 0.23° (degrees) of each other low in the dawn sky. 

But on December 21 they will pass each other only 6 arc minutes apart. To find a conjunction that close and visible in a darkened sky you have to go all the way back to March 5, 1226 when Jupiter passed only 3 arc minutes above Saturn at dawn. Thus the media headlines of a “Christmas Star” no one has seen for 800 years! 

Photographing the conjunction will be a challenge precisely because the planets will be so close to each other. Here are several methods I can suggest, in order of increasing complexity and demands for specialized gear. 


Easy — Shooting Nightscapes with Wide Lenses

This shows the field of view of various lenses on full-frame cameras (red outlines) and a 200mm lens with 1.4x tele-extender on a cropped frame camera (blue outline). The date is December 17 when the waxing crescent Moon also appears near the planet pair for a bonus element in a nightscape image.

Conjunctions of planets in the dusk or dawn twilight are usually easy to capture. Use a wide-angle (24mm) to short telephoto (85mm) lens to frame the scene and exposures of no more than a few seconds at ISO 200 to 400 with the lens at f/2.8 to f/4. 

The sky and horizon might be bright enough to allow a camera’s autoexposure and autofocus systems to work. 

Indeed, in the evenings leading up to and following the closest approach date of December 21 that’s a good method to use. Capture the planet pair over a scenic landscape or urban skyline to place them in context. 

For most locations the planets will appear no higher than about 15° to 20° above the southwestern horizon as it gets dark enough to see and shoot them, at about 5 p.m. local time. A 50mm lens on a full-frame camera (or a 35mm lens on a cropped frame camera) will frame the scene well. 

This was Jupiter and Saturn on December 3, 2020 from the Elbow Falls area on the Elbow River in the Kananaskis Country southwest of Calgary. This is a blend of 4 untracked images for the dark ground, stacked to smooth noise, for 30 seconds each, and one untracked image for the bright sky for 15 seconds to preserve colours and highlights, all with the 24mm Sigma lens and Canon EOS Ra at ISO 200.

NIGHTSCAPE TIP — Use planetarium software such as Stellarium (free), SkySafari, or StarryNight (what I used here) to simulate the framing with your lens and camera. Use that software to determine where the planets will be in azimuth, then use a photo planning app such as PhotoPills or The Photographer’s Ephemeris to plan where to be to place the planets over the scene you want at that azimuth (they’ll be at about 220° to 230° — in the southwest — for northern latitude sites). 

My ebook linked to at right has pages of tips and techniques for shooting nightscapes and time-lapses. 

This was Jupiter and Saturn on December 10, 2020 from Red Deer River valley, north of Drumheller, Alberta. This is a blend of 4 images for the dark ground, stacked to smooth noise, for 20 seconds each at f/5.6, and a single image for the sky for 5 seconds at f/2.8, all with the 35mm Canon lens and Canon EOS Ra at ISO 400. All untracked.

Harder — Shooting With Longer Lenses

The planet pair will sink lower and closer to the horizon, to set about 7:00 to 7:30 p.m. local time each night. 

As the sky darkens and the planet altitude decreases you can switch to ever-longer lenses to zoom in on the scene and still frame the planets above a carefully-chosen horizon, assuming you have very clear skies free of haze and cloud. 

For example, by 6 p.m. they will be low enough to allow a 135mm telephoto to frame the planets and still have the horizon in the frame. Using a longer lens has the benefit or resolving the two planets better, showing them as two distinct objects, which will become more of a challenge the closer you are to December 21. 

On December 21 wide-angle and even short telephoto lenses will likely show the two planets as an unresolved point of light, no brighter than Jupiter on its own.

On closest approach day the planets will be so close that using a wide-angle or even a normal lens might only show them as an unresolved blob of light. You’ll need more focal length to split the planets well into two objects. 

However, using longer focal lengths introduces a challenge — the motion of the sky will cause the planets to trail during long exposures, turning them from points into streaks. That trailing will get more noticeable more quickly the longer the lens you use. 

A rule-of-thumb says the longest exposure you can employ before trailing becomes apparent is 500 / the focal length of the lens. So for a 200mm lens, maximum exposure is 500 / 200 = 2.5 seconds. 

To be conservative, a “300 Rule” might be better, restricting exposures with a 200mm telephoto to 300 / 200 = 1.5 seconds. Now, 1.5 seconds might be long enough for the scene, especially if you use a fast lens wide open at f/2.8 or f/2 and a faster ISO such as 400 or 800. 

This shows the motion of Jupiter relative to Saturn from December 17 to 25, with the outer frame representing the field of view of a 200mm lens and 1.4x tele-extender on a cropped frame camera. The smaller frame shows the field of a telescope with an effective focal length of 1,200mm.

TELEPHOTO TIP — Be sure to focus carefully using Live View to manually focus on a magnified image of the planets. And refocus through an evening of shooting. While people fuss about getting the one “correct” exposure, it is poor focus that ruins more astrophotos. 


Even More Demanding — Tracking Longer Lenses 

This one popular sky tracker, the iOptron SkyGuider Pro, here with a telephoto lens. It and other trackers such as the Sky-Watcher Star Adventurer seen in the opening image, can be used with lenses and telescopes up to about 300mm focal length, if they are balanced well. Even longer lenses might work for the short exposures needed for the planets, but vibration and wind can blur images.

However, longer exposures might be needed later in the evening when the sky is darker, to set the planets into a starry background. After December 17 we will have a waxing Moon in the evening sky to light the sky and foreground, so the sky will not be dark, even from a rural site. 

Even so, to ensure untrailed images with long telephotos — and certainly with telescopes — you will need to employ a sky tracker, a device to automatically turn the camera to follow the sky. If you don’t have one, it’s probably too late to get one and learn how to use it! But if you have one, here’s a great opportunity to put it to use. 

Polar align it (you’ll have to wait for it to get dark enough to see the North Star) and then use it to take telephoto close-up images of the planets with exposure times that can now be as long as you like, though they likely won’t need to be more than 10 to 20 seconds. 

You can now also use a slower ISO speed for less noise. 

TRACKER TIP — Use a telephoto to frame just the planets, or include some foreground content such as a hilltop, if it can be made to fit in the frame. Keep in mind that the foreground will now blur from the tracking, which might not be an issue. If it is, take exposures of the foreground with the tracker motor off, to blend in later in processing. 


The Most Difficult Method — Using a Telescope

An alt-azimuth mounted GoTo scope like this Celestron SE6 can work for short exposures of the planets, provided it is aligned and is tracking properly. Good focus will be critical.

Capturing the rare sight of the planets as two distinct disks (not just dots of light) accompanied by their moons, all together in the same frame, is possible anytime between now and the end of the year. 

But … resolving the disks of the planets takes focal length — a lot of focal length! And that means using a telescope on a mount that can track the stars. 

While a sky tracker might work, they are not designed to handle long and heavy lenses and telescopes. You’d need a telescope on a solid mount, though it could be a “GoTo” telescope on an alt-azimuth mount. Such a mount, while normally not suited for long-exposure deep-sky imaging, will be fine for the short exposures needed for the planets.

You will need to attach your camera to the telescope using a camera adapter, so the scope becomes the lens. If you have never done this, to shoot closeups of the Moon for example, and don’t have the right adapters and T-rings, then this isn’t the time to learn how to do it.

A simulation of the view with a 1,200mm focal length telescope on December 21. Even with such a focal length the planet disks still appear small.

TELESCOPE TIP — As an alternative, it might be possible to shoot the planets using a phone camera clamped to the low-power eyepiece of a telescope, but focusing and setting the exposure can be tough. It might not be worth the fuss in the brief time you have in twilight, perhaps on the one clear night you get! Just use your telescope to look and enjoy the view! 

But if you have experience shooting the Moon through your telescope with your DSLR or mirrorless camera, then you should be all set, as the gear and techniques to shoot the planets are the same. 

This is the setup I might use for a portable rig best for a last-minute chase to clear skies. It’s a Sky-Watcher EQM-35 mount with a 105mm apo refractor (the long-discontinued Astro-Physics Traveler), and here with a 2x Barlow to double the effective focal length to 1,200mm.

However, once again the challenge is just how close the planets are going to get to each other. Even a telescope with a focal length of 1200mm (typical for a small scope) still gives a field of view 1° wide using a cropped frame camera. That’s 60 arc minutes, ten times the 6 arc minute separation of Jupiter and Saturn on December 21! 

TELESCOPE TIP — Use a 2x or 3x Barlow lens if needed to increase the effective focal length of the scope. Beware that introducing a Barlow into the light path usually requires racking the focus out and/or adding extension tubes to reach focus. Test your configuration as soon as possible to make sure you can focus it. 

TELESCOPE TIP — With such long focal lengths shoot lots of exposures. Some will be sharper than others. 

TELESCOPE TIP — But be sure to focus precisely, and refocus over the hour or so you might be shooting, as changing temperatures will shift the focus. You can’t fix bad focus! 

Jupiter and Saturn in the same telescope field on December 5, 2020. Some of the moons are visible in this exposure taken in twilight before the planets got too low in the southwest. This is a single exposure with a 130mm Astro-Physics apo refractor at f/6 (so 780mm focal length) for 4 seconds at ISO 200 with the Canon 6D MkII. The disks of the planets are overexposed to bring out the moons.

Short exposures under one second might be needed to keep the planet disks from overexposing. Capturing the moons of Jupiter (it has four bright moons) and Saturn (it has two, Titan and Rhea, that are bright) will require exposures of several seconds. Going even longer will pick up background stars.

Or … with DSLRs and mirrorless cameras, try shooting HD or 4K movies. They will likely demand a high and noisy ISO, but might capture the view more like you saw and remember it. 

FINAL TIP — Whatever combination of gear you decide to use, test it! Don’t wait until December 21 to see if it works, nor ask me if I think such-and-such a mount, telescope or technique will work. Test for yourself to find out.

Jupiter and Saturn taken in the deep twilight on December 3, 2020 from the Allen Bill flats area on the Elbow River in the Kananaskis Country southwest of Calgary, Alberta. This is a blend of 4 untracked images for the dark ground, stacked to smooth noise, for 2 minutes each at ISO 400, and two tracked images for the sky (and untrailed stars) for 30 seconds each at ISO 400, all with the 35mm Canon lens at f/2.8 and Canon EOS Ra. The tracker was the Sky-Watcher Star Adventurer 2i.

Don’t Fret or Compete. Enjoy! 

The finest images will come from experienced planetary imagers using high-frame-rate video cameras to shoot movies, from which software extracts and stacks the sharpest frames. Again, if you have no experience with doing that (I don’t!), this is not the time to learn! 

And even the pros will have a tough time getting sharp images due to the planets’ low altitude, even from the southern hemisphere, where some pro imagers have big telescopes at their disposal, to get images no one else in the world can compete with!

In short, use the gear you have and techniques you know to capture this unique event as best you can. And if stuff fails, just enjoy the view! 

Jupiter and Saturn taken December 3, 2020 from the Allen Bill flats area on the Elbow River in the Kananaskis Country southwest of Calgary, Alberta. This is a blend of 4 untracked images for the dark ground, stacked to smooth noise, for 2 minutes each at ISO 400, and two tracked images for the sky for 30 seconds at ISO 1600, all with the 35mm Canon lens at f/2.8 and Canon EOS Ra. The tracker was the Sky-Watcher Star Adventurer 2i.

If you miss closest approach day due to cloud, don’t worry. 

Even when shooting with telephoto lenses the photo ops will be better in the week leading up to and following December 21, when the greater separation of the planets will make it easier to capture a dramatic image of the strikingly close pairing of planets over an Earthly scene. 

Clear skies! 

— Alan, © 2020 AmazingSky.com 

Shooting with Canon’s EOS Ra Camera


IC 1805 in Cassiopeia (Traveler and EOS Ra)

I had the chance to test out an early sample of Canon’s new EOS Ra camera designed for deep-sky photography. 

Once every 7 years astrophotographers have reason to celebrate when Canon introduces one of their “a” cameras, astronomical variants optimized for deep-sky objects, notably red nebulas.

In 2005 Canon introduced the ground-breaking 8-megapixel 20Da, the first DLSR to feature Live View for focusing. Seven years later, in 2012, Canon released the 18-megapixel 60Da, a camera I still use and love.

Both cameras were cropped-frame DSLRs.

Now in 2019, seven years after the 60Da, we have the newly-released EOS Ra, the astrophoto version of the 30-megapixel EOS R released in late 2018. The EOS R is a full-frame mirrorless camera with a sensor similar to what’s in Canon’s 5D MkIV DSLR.

Here, I present a selection of sample images taken with the new EOS Ra.

Details on its performance is at my “first-look” review at Sky and Telescope magazine’s website.

IC 1805 in Cassiopeia (Traveler and EOS Ra)
The large emission nebula IC 1805 in Cassiopeia, aka the Heart Nebula. The round nebula at top right is NGC 896. The large loose star cluster at centre is Mel 15; the star cluster at left is NGC 1027. The small cluster below NGC 896 is Tombaugh 4. This is a stack of 8 x 6-minute exposures with the Canon EOS Ra mirrorless camera at ISO 1600 through the Astro-Physics Traveler apo refractor at f/6 with the Hotech field flattener. Stacked, aligned and processed in Photoshop.

Both versions of the EOS R have identical functions and menus.

The big difference is that the EOS Ra, as did Canon’s earlier “a” models, has a factory-installed filter in front of the sensor that transmits more of the deep red “hydrogen-alpha” wavelength emitted by glowing nebulas.

Normal cameras suppress much of this deep-red light as a by-product of their filters cutting out the infra-red light that digital sensors are very sensitive to, but that would not focus well.

NGC 7000 North America Nebula (105mm Apo & Canon EOS Ra)
The North America Nebula, NGC 7000, in Cygnus, taken with the new Canon EOS Ra factory-modified “astronomical” version of the Canon EOS R mirrorless camera. This is a stack of 4 x 6-minute exposures, with LENR on and at ISO 1600, through the Astro-Physics Traveler 105mm f/6 apo refractor with the Hutech field flattener.

I was sent an early sample of the EOS Ra, and earlier this autumn also had a sample of the stock EOS R.

Both were sent for testing so I could prepare a test report for Sky and Telescope magazine. The full test report will appear in an upcoming issue.

IC 1396 in Cepheus (Traveler and EOS Ra)
The large emission nebula IC 1396 in Cepheus with the orange “Garnet Star” at top, and the Elephant Trunk Nebula, van den Bergh 142, at bottom as a dark lane protruding into the emission nebula. This is a stack of 5 x 6-minute exposures with the Canon EOS Ra mirrorless camera at ISO 1600 through the Astro-Physics Traveler apo refractor at f/6 with the Hotech field flattener. Stacked, aligned and processed in Photoshop.

But my “first-look” review can be found here on the Sky and Telescope website.

Please click thru for comments on:

• How the Ra compares to previous “a” models and third-party filter-modified cameras

• How the Ra works for normal daylight photography

• Noise levels compared to other cameras

• Features unique to the EOS Ra, such as 30x Live View focusing

Messier 52 and the Bubble Nebula (Traveler and EOS Ra)
Messier 52 open cluster, at left, and the Bubble Nebula, NGC 7635 below and to the right of it, at centre, plus the small red nebula NGC 7538 at right. The open cluster at lower right is NGC 7510. All in Cassiopeia. This is a stack of 8 x 6-minute exposures at ISO 1600 with the Canon EOS Ra camera and Astro-Physics Traveler apo refractor at f/6 with the Hotech field flattener. No LENR dark frame subtraction employed as the temperature was -15° C.


UPDATE — November 25, 2019

As part of further testing I shot the Heart and Soul Nebulas in Cassiopeia through my little Borg 77mm f/4 astrograph with both the EOS Ra and my filter-modified 5D MkII (modified years ago by AstroHutech) to compare which pulled in more nebulosity. It looked like a draw.

Both images are single 8-minute exposures, taken minutes apart and developed identically in Adobe Camera Raw, but adjusted for colour balance to equally neutralize the sky background. The histograms look similar. Even so, the Ra looks a little redder overall. But keep in mind a sky or nebula can be made to appear any shade of red you like in processing.

The question is which camera shows more faint nebulosity?

The modified 5D MkII has always been my favourite camera for this type of astrophotography, picking up more nebulosity than other “a” models I’ve tested, including the Nikon D810a.

But in this case, I’d say the EOS Ra is performing as well as, if not better than the 5D MkII. How well any third-party modified camera you buy now performs will depend which, if any, filter the modifier installs in front of the sensor. So your mileage will vary.

EOS Ra and 5D MkII Comparison


For most of my other testing I shot through my much-prized Astro-Physics Traveler, a 105mm aperture f/6 apochromatic refractor on the Astro-Physics Mach1 mount.

To connect the EOS Ra (with its new RF lens mount) to my existing telescope-to-camera adapter and field flattener lens I used one of Canon’s EF-EOS R lens adapters.

EOS Ra on Scope

EOS Ra on Scope CU

The bottom line is that the EOS Ra works great!

It performs very well on H-alpha-rich nebulas and has very low noise. It will be well-suited to not only deep-sky photography but also to wide-field nightscape and time-lapse photography, perhaps as Canon’s best camera yet for those applications.

EOS Ra Front View-Face On

WHAT ABOUT THE PRICE?

The EOS Ra will sell for $2,500 US, a $700 premium over the cost of the stock EOS R. Some complain. Of course, if you don’t like it, you don’t have to buy it. This is not an upgrade being forced upon you.

As I look at it, it is all relative. When Nikon’s astronomy DSLR, the 36 Mp D810a, came out in 2015 it sold for $3,800 US, $1,300 more than the EOS Ra. It was, and remains a fine camera, if you can find one. It is discontinued.

A 36 Mp cooled and dedicated CMOS astro camera, the QHY367, with the same chip as the D810a, goes for $4,400, $1,900 more than the Ra. Yes, it will produce better images I’m sure than the EOS Ra, but deep-sky imaging is all it can do. At a cost, in dollars and ease of use.

And yes, buying a stock EOS R and having it modified by a third party costs less, and you’ll certainly get a good camera, for $300 to $400 less than an Ra. But …

• The EOS Ra has a factory adjusted white balance for ease of “normal” use — no need to buy correction filters. So there’s a $$ saving there, even if you can find clip-in correction filters for the EOS R — you can’t.

• And the Ra retains the sensor dust cleaning function. Camera modifier companies remove it or charge more to reinstall it.

• And the 30x live view magnification is very nice.

• The EOS Ra also carries a full factory warranty.

Do I wish the EOS Ra had some other key features? Sure. A mode to turn all menus red would be nice. As would an intervalometer built-in, one that works with the Bulb Timer to allow sequences of programmed multi-minute exposures. Both could be added in with a firmware update.

And providing a basic EF-EOS R lens adapter in the price would be a welcome plus, as one is essential to use the EOS Ra on a telescope.

That’s my take on it. I’ll be buying one. But then again I bought the 20Da, twice!, and the 60Da, and I hate to think what I paid for those much less capable cameras.

Canon EOS Ra and 15-35mm

BONUS TEST — The RF 15-35mm L Lens

Canon is also releasing an impressive series of top-class RF lenses for their R mirrorless cameras. The image below is an example astrophoto with the new RF 15-35mm f/2.8 L zoom lens, an ideal combination of focal lengths and speed for nightscape shooting.

Orion and Winter Stars Rising
Orion and the winter stars rising on a late October night, with Sirius just clearing the horizon at centre bottom, Capella and the Pleiades are at top. M44 cluster is at far left. Taken with the Canon 15-35mm RF lens at 15mm and f/2.8 and the EOS Ra camera at ISO 800 as part of testing. A stack of 4 x 2-minute exposures on the Star Adventurer tracker.

Below is a further set of stacked and processed images with the RF 15-35mm L lens, taken in quick succession, at 15mm, 24mm, and 35mm focal lengths, all shot wide open at f/2.8. The EOS Ra was on the Star Adventurer tracker (as below) to follow the stars.

EOS Ra on Star Adventurer

Click or tap on the images below to view a full-resolution version for closer inspection.

Autumn Milky Way (15-35mm RF at 15mm + EOS Ra).jpg
15mm — Northern autumn Milky Way with RF 15-35mm at f/2.8 and at 15mm focal length. Taken with the EOS Ra at ISO 800 for a stack of 4 x 2-minute exposures.

Autumn Milky Way (15-35mm RF at 24mm + EOS Ra).jpg
24mm — Northern autumn Milky Way with RF 15-35mm at f/2.8 and at 24mm focal length. Taken with the EOS Ra at ISO 800 for a stack of 2 x 2-minute exposures.

Autumn Milky Way (15-35mm RF at 35mm + EOS Ra).jpg
35mm — Northern autumn Milky Way with RF 15-35mm at f/2.8 and at 35mm focal length. Taken with the EOS Ra at ISO 800 for a stack of 2 x 2-minute exposures.

The RF 15-35mm lens performs extremely well at 15mm exhibiting very little off-axis aberrations at the corners.

Off-axis aberrations do increase at the longer focal lengths but are still very well controlled, and are much less than I’ve seen on my older zoom and prime lenses in this focal length range.

The RF 15-35mm is a great complement to the EOS Ra for wide-field Milky Way images.

I was impressed with the new EOS Ra. It performs superbly for astrophotography.

Again, click through to Sky and Telescope for “first look” details on the test results.

— Alan, November 6, 2019 / UPDATED Nov 25, 2019 / © 2019 AmazingSky.com 

 

Testing the MSM Tracker


MSM Test Title

A new low-cost sky tracker promises to simplify not only tracking the sky but also taking time-lapses panning along the horizon. It works but …

If you are an active nightscape photographer chances are your social media feeds have been punctuated with ads for this new low-cost tracker from MoveShootMove.com. 

For $200, much less than popular trackers from Sky-Watcher and iOptron, the SiFo unit (as it is labelled) offers the ability track the sky, avoiding any star trails. That alone would make it a bargain, and useful for nightscape and deep-sky photographers. 

But it also has a function for panning horizontally, moving incrementally between exposures, thus the Move-Shoot-Move designation. The result is a time-lapse movie that pans along the horizon, but with each frame with the ground sharp, as the camera moves only between exposures, not during them. 

 

MSM Polar Aligned Side V1
The Move-Shoot-Move Tracker
The $200 MSM can be polar aligned using the optional laser, shown here, or an optical polar scope to allow to follow the sky. The ball head is user supplied. 

Again, for $200 this is an excellent feature lacking in trackers like the Sky-Watcher Star Adventurer or iOptron SkyTracker. The Sky-Watcher Star Adventurer Mini does, however, offer both tracking and “move-shoot-move” time-lapse functions, but at a cost of $300 to $400 U.S., depending on accessories. 

All these functions are provided in a unit that is light (weighing 700 grams with a tripod plate and the laser) and compact (taking up less space in your camera bag than most lenses). By comparison, the Star Adventurer Mini weighs 900 grams with the polar scope, while the original larger Star Adventurer is 1.4 kg, double the MSM’s weight. 

Note, that the MSM’s advertised weight of 445 grams does not include the laser or a tripod plate, two items you need to use it. So 700 grams is a more realistic figure, still light, but not lighter than the competition by as much as you might be led to believe. 

Nevertheless, the MSM’s small size and weight make it attractive for travel, especially for flights to remote sites. Construction is solid and all-metal. This is not a cheap plastic toy.

But does it work? Yes, but with several important caveats that might be a concern for some buyers. 

What I Tested

I purchased the Basic Kit B package for $220 U.S., which includes a small case, a laser pointer and bracket for polar alignment (and with a small charger for the laser’s single 3.7-volt battery), and with the camera sync cable needed for time-lapse shooting. 

I also purchased the new “button” model, not the older version that used a knob to set various tracking rates. 

 

MSM with Canon 6D MkII
MSM Fitted Out
Keep in mind that to use any tracker like the MSM you will need a solid tripod with a head good enough to hold the tracker and camera steady when tipped over when polar aligned, and another ball head on the tracker itself.

The ball head needed to go on top of the tracker is something you supply. The kit does come with two 3/8-inch stud bolts and a 3/8-to1/4-inch bushing adapter, for placing the tracker on tripods in the various mounting configurations I show below. 

The first units were labelled as ‘SiFo,” but current units now carry the Gauda brand name. I’ll just call it the MSM. 

I purchased the gear from the MSM website, and had my order fulfilled and shipped to me in Canada from China with no problems. 

Tracking the Sky in Nightscapes

The attraction is its tracking function, allowing a camera to follow the sky and take exposures longer than any dictated by “500” or “NPF” Rules to avoid any star trailing. 

Exposures can be a minute or more to record much more depth and detail in the Milky Way, though the ground will blur. But blending tracked sky exposures with untracked ground exposures gets around that, and with the MSM it’s easy to turn on and off the tracking motor, something not possible with the low-cost wind-up Mini Track from Omegon. 

MSM Polar Aligned Side V2
Mounting on the Side
The MSM is shown in illustrations and instructions mounted by its side panel bolt hole. This works, but produced problems with the gears not meshing well and the MSM not tracking at all for initial exposures. 

The illustrations and instructions (in a PDF well-hidden off the MSM Buy page) show the MSM mounted using the 1/4-20 bolt hole on the side of the unit opposite the LED-illuminated control panel. While this seems to be the preferred  method, in the first unit I tested I found it produced serious mis-tracking problems. 

MSM Test (On Side) 1 minute 50mm
50mm Lens Set, Mounted on the Side
A set of five consecutive 1-minute exposures taken with the original SiFo-branded MSM mounted by its side bolt hole showed the MSM’s habit of taking several minutes for the gears to mesh and to begin tracking. Tap or click to download full-res version.

With a Canon 6D MkII and 50mm f/1.4 lens (not a particularly heavy combination), the MSM’s gears would not engage and start tracking until after about 5 minutes. The first exposures were useless. This was also the case whenever I moved the camera to a new position to re-frame the scene or sky. Again, the first few minutes produced no or poor tracking until the gears finally engaged. 

This would be a problem when taking tracked/untracked sets for nightscapes, as images need to be taken in quick succession. It’s also just plain annoying.

However, see the UPDATE at the end for the performance of a new Gauda-branded unit that was sent to me. 

Sagittarius - Red Enhancer Filter
50mm Nightscape
With patience and persistence you can get well-tracked nightscapes with the MSM. This is a single 1-minute exposure with a 50mm lens. Tap or click to download full-res version.

Mounting Options

The solution was to mount the MSM using the 3/8-inch bolt hole on the back plate of the tracker, using the 1/4-20 adapter ring to allow it to attach to my tripod head. This still allowed me to tip the unit up to polar align it. 

MSM Polar Aligned Back V1
Mounting on the Back
Mounting the MSM using its back plate produced more reliable tracking results, though requires swapping mounting bolts and 3/8-1/4-inch adapter rings from the preferred method of mounting the MSM for time-lapse work. 

Tracking was now much more consistent, with only the first exposure usually badly trailed. But subsequent exposures all tracked, but with varying degrees of accuracy as I show below. 

When used as a tracker, you need to control the camera’s exposure time with an external intervalometer you supply, to allow setting exposures over 30 seconds long. 

The MSM offers a N and S setting, the latter for use in the Southern Hemisphere. A 1/2-speed setting turns the tracker at half the normal sidereal rate, useful for nightscapes as a compromise speed to provide some tracking while minimizing ground blurring. 

Polar Alignment

For any tracker to track, its rotation axis has to be aimed at the Celestial Pole, near Polaris in the Northern Hemisphere, and near Sigma Octantis in the Southern Hemisphere. 

MSM Tracker with Laser Pointer (Red Light Version)
Polar Aligning on Polaris
The MSM’s bright laser pointer is useful for aiming the tracker at the North Celestial Pole, located about a degree away from Polaris in the direction of Alkaid, the end star in the Handle of the Big Dipper or Plough. 

I chose the laser pointer option for this, rather than the polar alignment scope. The laser attaches to the side of the MSM using a small screw-on metal bracket so that it points up along the axis of rotation, the polar axis. 

The laser is labeled as a 1mw unit, but it is far brighter than any 1mw I’ve used. This does make it bright, allowing the beam to show up even when the sky is not dark. The battery is rechargeable and a small charger comes with the laser. Considering the laser is just a $15 option, it’s a bargain. But ….


UPDATE ADDED SEPTEMBER 1

Since I published the review, I have had the laser professionally tested, and it measured as having an output of 45 milliwatts. Yet it is labeled as being under 1 milliwatt. This is serious misrepresentation of the specs, done I can only assume to circumvent import restrictions. In Canada it is now illegal to import, own, or use any green laser over 5 milliwatts, a power level that would be sufficient for the intended use of polar aligning. 45mw is outright illegal. 


So be warned, use of this laser will be illegal in some areas. And use of any green laser will be illegal close to airports, and outlawed entirely in some jurisdictions such as Australia, a fact the MSM website mentions. 

The legal alternative is the optical polar alignment scope. I already have several of those, but my expectation that I could use one I had with the same bracket supplied with the laser were dashed by the fact that the bracket’s hole is too narrow to accept any of the other polar alignment scopes I have, which are all standard items. I you want a polar scope, buy theirs for $70. 

However, if you can use it where you live, the laser works well enough, allowing you to aim the tracker at the Pole just by eye. For the wide lenses the tracker is intended to be used with, eyeball alignment proved good enough.

Just be very, very careful not to accidentally look down the beam. Seriously. It is far too easy to do by mistake, but doing so could damage your eye in moments. 

Tracking the Sky in Deep-Sky Images

How well does the MSM actually track? In tests of the original SiFo unit I bought, and in sets of exposures with 35mm, 50mm, and 135mm lenses, and with the tracker mounted on the back, I found that 25% to 50% of the images showed mis-tracking. Gear errors still produced slightly trailed stars. This gear error shows itself more as you shoot with longer focal lengths. 

MSM Test (On Back) 2 min 35mm
35mm Lens Set, Mounted on the Back
A set of 2-minute exposures with the MSM mounted by its back plate showed better tracking with quicker gear meshing, though still with some frames showing trailing. Tap or click to download full-res version.

The MSM is best for what it is advertised as — as a tracker for nightscapes with forgiving wide-angle lenses in the 14mm to 24mm range. With longer lenses, expect to throw away a good number of exposures as unusable. Take twice as many as you think you might need.

MSM Test (On Back) 1 min 135mm
135mm Telephoto Lens Set
A set of 20 one-minute exposures with a 135mm lens showed more than half with unusable amounts of mis-tracking. But enough worked to be usable! Tap or click to download full-res version.

With a 135mm lens taking Milky Way closeups, more than half the shots were badly trailed. Really badly trailed. This is not from poor polar alignment, which produces a gradual drift of the frame, but from errors in the drive gears, and random errors at that, not periodic errors. 

To be fair, this is often the case with other trackers as well. People always want to weight them down with heavy and demanding telephotos for deep-sky portraits, but that’s rarely a good idea with any tracker. They are best with wide lenses.

That said, I found the MSM’s error rate and amount to be much worse than with other trackers. With the Star Adventurer models and a 135mm lens for example, I can expect only 20% to 25% of the images to be trailed, and even then rarely as badly as what the MSM exhibited.

See the UPDATE at the end for the performance of the replacement Gauda-branded unit sent to me with the promise of much improved tracking accuracy. 

The Arrow, Dumbbell, and Coathanger
Sagitta and Area with the 135mm
The result of the above set was a stack of 8 of the best for a fine portrait of the Milky Way area in Sagitta, showing the Dumbbell Nebula and Coathanger asterism. Each sub-frame was 1 minute at f/2 and ISO 1600. Tap or click to download full-res version.

Yes, enough shots worked to be usable, but it took using a fast f/2 lens to keep exposure times down to a minute to provide that yield. Users of slow f/5.6 kit-zoom lenses will struggle trying to take deep-sky images with the MSM. 

In short, this is a low-cost tracker and it shows. It does work, but not as well as the higher-cost competitors. But restrict it to wide-angle lenses and you’ll be fine. 

Panning the Ground 

The other mode the MSM can be used in is as a time-lapse motion controller. Here you mount the MSM horizontally so the camera turns parallel to the horizon (or it can be mounted vertically for vertical panning, a mode I rarely use and did not test). 

MSM Tracker Taking Time-Lapse in Moonlight
The MSM at Work
I performed all the time-lapse testing from my rural backyard on nights in mid-August 2019 with a waning Moon lighting the sky. 

This is where the Move-Shoot-Move function comes in. 

The supplied Sync cable goes from the camera’s flash hot shoe to the MSM’s camera jack. What happens is that when the camera finishes an exposure it sends a pulse to the MSM, which then quickly moves while the shutter is closed by the increment you set.

There is a choice of 4 speeds, marked in degrees-per-move: 0.05°, 0.2°, 0.5°, and 1.0°. For example, as the movie below shows, taking 360 frames at the 1° speed results in a complete 360° turn.

 

MSM Control Panel CU
Time-Lapse Speeds
The control panel offers a choice of N and S rotation directions, a 1/2-speed rate for partially tracked nightscapes, and Move-Shoot-Move rates per move of 0.05°, 0.2°, 0.5° and a very fast 1° setting. The Sync cable plugs into the jack on the MSM. The other jack is for connecting to a motion control slider, a function I didn’t test.

The MSM does the moving, but all the shutter speed control and intervals must be set using a separate intervalometer, either one built into the camera, or an outboard hardware unit. The MSM does not control the camera shutter. In fact, the camera controls the MSM.

Intervals should be set to be about 2 seconds longer than the shutter speed, to allow the MSM to perform its move and settle. 

This connection between the MSM and camera worked very well. It is unconventional, but simple and effective.

MSM Time-Lapse Correct
Mounting for Time-Lapse
The preferred method of mounting the MSM for time-lapses is to do so “upside-down” with its rotating top plate at bottom attached to the tripod. Thus the whole MSM and camera turns, preventing the Sync cable from winding up during a turn. 

Too Slow or Too Fast

The issue is the limited choice of move speeds. I found the 0.5° and 1° speeds much too fast for night use, except perhaps for special effects in urban cityscapes. Even in daytime use, when exposure times are very short, the results are dizzying, as I show below. 

Even the 0.2°-per-move speed I feel is too fast for most nightscape work. Over the 300 exposures one typically takes for a time-lapse movie, that speed will turn the MSM (300 x 0.2°) = 60 degrees. That’s a lot of motion for 300 shots, which will usually be rendered out at 24 or 30 frames per second for a clip that lasts 10 to 12 seconds. The scene will turn a lot in that time.

On the other hand, the 0.05°-per-move setting is rather slow, producing a turn of (300 x 0.05°) = 15° during the 300 shots. 

That works, but with all the motion controllers I’ve used — units that can run at whatever speed they need to get from the start point to the end point you set — I find a rate of about 0.1° per move is what works best for a movie that provides the right amount of motion. Not too slow. Not too fast. Just right. 

MSM Time-Lapse Correct CU
Inverted Control Panel
When mounted as recommended for time-lapses, the control panel does end up upside-down. 


UPDATE ADDED DECEMBER 21, 2019

From product photos on the MoveShootMove.com website now it appears that the tracker is now labeled MSM, as it should have been all along.

Most critically, perhaps in response to this review and my comments here, the time-lapse speeds have been changed to 0.05, 0.075, 0.1 and 0.125 degrees per move, adding the 0.1°/move speed I requested below and deleting the overly fast 0.5° and 1.0° speeds.

Plus it appears the new units have the panel labels printed the other way around so they are not upside down for most mounting situations.

I have not tested this new version, but these speeds sound much more usable for panning time-lapses. Bravo to MSM for listening! 

MSM Rotator 2019


Following the Sky in a Time-Lapse

The additional complication is trying to get the MSM to also turn at the right rate to follow the sky — for example, to keep the galaxy core in frame during the time-lapse clip. I think doing so produces one of the most effective time-lapse sequences. 

But to do that with any device requires turning at a rate of 15° per hour, the rate the sky moves from east to west.

Because the MSM provides only set fixed speeds, the only way you have of controlling how much it moves over a given amount of time, such as an hour, is to vary the shutter speed. 

I found that to get the MSM to follow the Milky Way in a time-lapse using the 0.05° rate and shooting 300 frames required shooting at a shutter speed of 12 seconds. No more, no less. 

MSM Time-Lapse Top Plate
Top Plate Display
When mounted “upside-down” for a time-lapse the top surface provides the N-S direction arrows (N moves clockwise) and a small, handy bubble level.

Do the Math

Where does that number come from? 

At its rate of 0.05°/move, the MSM will turn 15° over 300 shots. The sky moves 15° in one hour, or 3600 seconds. So to fit 300 shots into 3600 seconds means each shot has to be no longer than (3600/300) = 12 seconds long. 

The result works, as I show in the sampler movie. 

But 12 seconds is a rather short shutter speed on a dark, moonless night with the Milky Way. 

For properly exposed images you would need to shoot at very fast apertures (f/1.4 to f/2) and/or high and noisy ISO speeds. Neither are optimal. But they are forced upon you by the MSM’s restricted rates. 

Using the faster 0.2° rate (of the original model) yields a turn of 60° over 300 shots. That’s four hours of sky motion. So each exposure now has to be 48 seconds long for the camera to follow the sky, four times longer because the drive rate is now four times faster. 

A shutter speed of 48 seconds is a little too long in my opinion. Stars in each frame will trail. Plus a turn of 60° over 300 shots is quite a lot, producing a movie that turns too quickly. 

MSM Time-Lapse Inverted
Alternative Time-Lapse Configuration
The other option is to mount the MSM so the control panel is right-side-up and the top turn-table (the part that turns and that the camera is attached to) is on top. Now only the camera turns; the MSM does not. This works but the Sync cable can wrap around and bind in long turns. For short turns of 30° to 60° it is fine. 

By far the best speed for motion control time-lapses would be 0.1° per move. That would allow 24-second exposures to follow the sky, allowing a stop less in aperture or ISO speed.  (DECEMBER 21 UPDATE: That speed seems to now be offered.)

Yes, having only a limited number of pre-wired speeds does make the MSM much easier to program than devices like the Star Adventurer Mini or SYRP Genie Mini that use wireless apps to set their functions. No question, the MSM is better suited to beginners who don’t want to fuss with lots of parameters. 

As it is, getting a decent result requires some math and juggling of camera settings to make up for the MSM’s limited choices of speeds. 

Time-Lapse Movie Examples

This compilation shows examples of daytime time-lapses taken at the fastest and dizzying 0.5° and 1.0° speeds, and night time-lapses taken at the slower speeds. The final clip is taken at 0.05°/move and with 12-second exposures, a combination that allowed the camera to nicely follow the Milky Way, albeit at a slow pace. Taking more than the 300 frames used here would have produced a clip that turned at the same rate, but lasted longer. 

Battery Life

The MSM is powered off an internal rechargeable battery, which can be charged from any 5-volt charger you have from a mobile phone. 

The MSM uses a USB-C jack for the power cable, but a USB-A to USB-C cord is supplied, handy as you might not have one if you don’t have other USB-C devices. 

The battery lasted for half a dozen or more 300-shot time-lapses, enough to get you through at least 2 or 3 nights of shooting. However, my testing was done on warm summer nights. In winter battery life will be less. 

While the built-in battery is handy, in the field should you find battery level low (the N and S switches blink as a warning) you can’t just swap in fresh batteries. Just remember to charge up before heading out. Alternatively, it can be charged from an external 5V battery pack such as used to prolong cell phone life. 

Hercules and Corona Borealis (50mm 6D)
The constellations of Hercules and Corona Borealis in the northern spring and summer sky. This is a stack of 3 x 2-minute exposures with the 50mm Sigma lens at f/2.8 and Canon 6D at ISO 800, plus an additional 2 min exposure through the Kenko Softon filter to add the star glows. All tracked on the original MSM SiFo Tracker from China. Tap or click to download full-res version.

Other Caveats

The MSM does not offer, nor does it promise, any form of automated panorama shooting. This is where the device turns by, say, 15° to 45° between shots, to shoot the segments for a still-image panorama. More sophisticated motion controllers from SYRP and Edelkrone offer that function, including the ability to mate two devices for automated multi-tier panoramas. 

Nor does the MSM offer the more advanced option of ramping speeds up and down at the start and end of a time-lapse. It moves at a constant rate throughout. 

While some of the shortcomings could perhaps be fixed with a firmware update, there is no indication anywhere that its internal firmware can be updated through the USB-C port. 

MSM Polar Aligned On Back


UPDATE ADDED OCTOBER 7, 2019

Since I published the review, MSM saw the initial test results and admitted that the earlier units like mine (ordered in June) exhibited large amounts of tracking error. They sent me a replacement unit, now branded with the Gauda label. According to MSM it contains a more powerful motor promised to improve tracking accuracy and making it possible to take images with lenses as long as 135mm.

I’m sorry to report it didn’t.

MSM Gauda-135mm Back-NE
This shows 300% blow-ups of a star field rising in the northeast sky taken with the new Gauda unit and with a 135mm lens, each for 2 minutes in quick succession. Less than 50% of the frames were useable and untrailed. (The first frames were shot through high clouds.)

MSM Gauda-135mm Back-Zenith
Taken the same night as the previous set, this shows 24 shots taken in quick succession with the same 135mm lens for 2 minutes each but with the camera aimed overhead to the zenith. None of the images were usable. All were trailed, most very badly.

In tests with the 135mm lens the new, improved MSM still showed lots of tracking error, to the point that images taken with a lens as long as this were mostly unusable.

Tap or click on the images to download full-res versions.

The short movie above takes the full-frame images from the zenith set of 24 frames taken over 48 minutes and turns them into a little time-lapse. It shows how the mechanism of the MSM seems to be wobbling the camera around in a circle, creating the mis-tracking.

Comparison with the Star Adventurer

As a comparison, the next night I used a Sky-Watcher Star Adventurer (the full-size model not the Mini) to shoot the same fields in the northeast and overhead with the same 135mm lens and with the same ball-head, to ensure the ball-head was not at fault. Here are the results:

Star Adventurer-135mm-NE
The same field looking northeast, with 300% blow-ups of 2-minute exposures with the 135mm lens and Star Adventurer tracker. As is usual with this unit, about 20% of the frames show mis-tracking, but none as badly as the MSM.

Star Adventurer-135mm-Zenith
Aiming the camera to the zenith the Star Adventurer again showed a good success rate with a slightly greater percentage trailed, but again, none as badly as the MSM.

The Star Adventurer performed much better. Most images were well-tracked. Even on those frames that showed trailing, it was slight. The Star Adventurer is a unit you can use to take close-ups of deep-sky fields with telephoto lenses, if that’s your desire.

By contrast, the MSM is best used — indeed, I feel can only be used practically — with wide-angle lenses and with exposures under 2 minutes. Here’s a set taken with a 35mm lens, each for 2 minutes.

MSM Gauda-35mm Side-NE
This is a set of consecutive 2-minute exposures with a 35mm lens and Canon 6D MkII on the MSM tracker, with the tracker mounted using the side 1/4-20 bolt hole. It was aimed to the northeast. About half the images showed significant trailing.

With the more forgiving 35mm lens, while more images worked, the success rate was still only 50%.

What I did not see with the new Gauda unit was the 5-minute delay before the gears meshed and tracking began. That issue has been resolved by the new, more powerful motor. The new Gauda model does start tracking right away.

But it is still prone to significant enough drive errors that stars are often trailed even with a 35mm lens (this was on a full-frame Canon 6D MkII).


UPDATED CONCLUSIONS (December 21, 2019)

The MSM tracker is low-cost, well-built, and compact for easy packing and travel. It performs its advertised functions well enough to allow users to get results, either tracked images of the Milky Way and constellations, or simple motion-control time-lapses. 

But it is best used — indeed I would suggest can only be used — with wide-angle lenses for tracked Milky Way nightscapes. Even then, take more shots than you think you need to be sure enough are well-tracked and usable. 

It can also be used for simple motion-control time-lapses, provided you do to the math to get it to turn by the amount you want, working around the too-slow or too-fast speeds. The new 0.1° per move speed (added in models as of December 2019) seems a reasonable rate for most time-lapses. 

However, I think aspiring time-lapse photographers will soon outgrow the MSM’s limitations for motion-control sequences. But it can get you started. 

If you really value its compactness and your budget is tight, the MSM will serve you well enough for tracked nightscape shooting with wide-angle lenses.

But if you wish to take close-ups of starfields and deep-sky objects with longer lenses, consider a unit like the Sky-Watcher Star Adventurer for its lower tracking errors. Or the Star Adventurer Mini for its better motion-control time-lapse functions. 

— Alan Dyer / August 22, 2019 / UPDATED October 7, 2019 / © 2019 AmazingSky.com

 

Testing the Nikon Z6 for Astrophotography


Nikon Z Title

I put the new Nikon Z6 mirrorless camera through its paces for astrophotography. 

Following Sony’s lead, in late 2018 both Nikon and Canon released their entries to the full-frame mirrorless camera market. 

Here I review one of Nikon’s new mirrorless models, the Z6, tested solely with astrophotography in mind. I did not test any of the auto-exposure, auto-focus, image stabilization, nor rapid-fire continuous mode features. 

For full specs and details on the Z-series cameras see Nikon USA’s website.

Sony a7III vs Nikon Z6 copy

In my testing I compared the Nikon Z6 (at right above) to two competitive cameras, the relatively new Sony a7III mirrorless (at left above) and 2015-vintage Nikon D750 DSLR.

All three are “entry-level” full-frame cameras, with 24 megapixels and in a similar $2,000 price league, though the older D750 now often sells at a considerable discount.


Disclosure

I should state at the outset that my conclusions are based on tests conducted over only three weeks in mid-winter 2019 while I had the camera on loan from Nikon Canada’s marketing company. 

I don’t own the camera and didn’t have many moonless nights during the loan period to capture a lot of “beauty” shots under the stars with the Z6.

Auroral Arc (January 10, 2019)
An arc of the auroral oval across the northern horizon on the night of January 10-11, 2019. With the Sigma 14mm lens and Nikon Z6 for testing.

However, I think my testing was sufficient to reveal the camera’s main traits of interest — as well as deficiencies it might have — for astrophotography.

I should also point out that I do not participate in “affiliate links,” so I have no financial motivation to prompt you to buy gear from merchants. 

But if you buy my ebook (at right), which features reams of sections on camera and time-lapse gear, I would be very pleased! 


TL;DR Conclusions

In short — I found the Nikon Z6 superb for astrophotography. 

Nikon Z6 Screens copy

Summary:

• It offers as low a noise level as you’ll find in a 24-megapixel full-frame camera, though its noise was not significantly lower than the competitive Sony a7III, nor even the older Nikon D750. 

• The Z6’s ISO-invariant sensor proved excellent when dealing with the dark underexposed shadows typical of Milky Way nightscapes.

• The Live View was bright and easy to enhance to even brighter levels using the Movie mode to aid in framing nightscapes. 

• When shooting deep-sky images through telescopes using long exposures, the Z6 did not exhibit any odd image artifacts such as edge vignetting or amplifier glows, unlike the Sony a7III. See my review of that camera in my blog from 2018. 

Recommendations: 

• Current owners of Nikon cropped-frame cameras wanting to upgrade to full-frame would do well to consider a Z6 over any current Nikon DSLR. 

• Anyone wanting a full-frame camera for astrophotography and happy to “go Nikon” will find the Z6 nearly perfect for their needs. 


Nikon Z6 vs. Z7

Nikon Front View copy

I opted to test the Z6 over the more expensive Z7, as the 24-megapixel Z6 has 6-micron pixels resulting in lower noise (according to independent tests) than the 46 megapixel Z7 with its 4.4 micron pixels. 

In astrophotography, I feel low noise is critical, with 24-megapixel cameras hitting a sweet spot of noise vs. resolution.

However, if the higher resolution of the Z7 is important for your daytime photography needs, then I’m sure it will work well at night. The Nikon D850 DSLR, with a sensor similar to the Z7, has been proven by others to be a good astrophotography camera, albeit with higher noise than the lesser megapixel Nikons such as the D750 and Z6.

NOTE: Tap or click on images to download and display them full screen for closer inspection.


High ISO Noise

Comparison - Noise at 3 ISOs
The three 24-megapixel cameras compared at three high ISO levels in a close-up of a dark-sky nightscape.

To test noise in a real-world situation, I shot a dark nightscape scene with the three cameras, using a 24mm Sigma Art lens on the two Nikons, and a 24mm Canon lens on the Sony via a MetaBones adapter. I shot at ISOs from 800 to 12,800, typical of what we use in nightscapes and deep-sky images. 

The comparison set above shows performance at the higher ISOs of 3200 to 12,800. I saw very little difference among the trio, with the Nikon Z6 very similar to the Sony a7III, and with the four-year-old Nikon D750 holding up very well against the two new cameras. 

The comparison below shows the three cameras on another night and at ISO 3200.

Noise at 3200-3 Cameras
The three cameras compared for noise at properly exposed moonlit scenes at ISO 3200, a typical nightscape setting.

Both the Nikon Z6 and Sony a7III use a backside illuminated or “BSI” sensor, which in theory is promises to provide lower noise than a conventional CMOS sensor used in an older camera such as the D750. 

In practice I didn’t see a marked difference, certainly not as much as the one- or even 1/2-stop improvement in noise I might have expected or hoped for.

Nevertheless, the Nikon Z6 provides as low a noise level as you’ll find in a camera offering 24 megapixels, and will perform very well for all forms of astrophotography. 


ISO Invariance

Comparison - ISO Invariancy
The three cameras compared for ISO invariance at 0EV (well exposed) and -5EV (5 stops underexposed then brightened in processing).

Nikon and Sony both employ an “ISO-invariant” signal flow in their sensor design. You can purposely underexpose by shooting at a lower ISO, then boost the exposure later “in post” and end up with a result similar to an image shot at a high ISO to begin with in the camera. 

I find this feature proves its worth when shooting Milky Way nightscapes that often have well-exposed skies but dark foregrounds lit only by starlight. Boosting the brightness of the landscape when developing the raw files reveals details in the scene without unduly introducing noise, banding, or other artifacts such as magenta tints. 

That’s not true of “ISO variant” sensors, such as in most Canon cameras. Such sensors are far less tolerant of underexposure and are prone to noise, banding, and discolouration in the brightened shadows.

See my test of the Canon 6D MkII for its performance under the differing demands of nightscape photography and deep-sky imaging.

To test the Z6’s ISO invariance (as shown above) I shot a dark nightscape at ISO 3200 for a properly exposed scene, and also at ISO 100 for an image underexposed by a massive 5 stops. I then boosted that image by 5 stops in exposure in Adobe Camera Raw. That’s an extreme case to be sure. 

I found the Z6 provided very good ISO invariant performance, though with more chrominance specking than the Sony a7III and Nikon D750 at -5 EV.

Below is a less severe test, showing the Z6 properly exposed on a moonlit night and at 1 to 4 EV steps underexposed, then brightened in processing. Even the -4 EV image looks very good.

Comparison-ISO Invariancy in Moonlight
This series taken under moonlight shows that even images underexposed by -4 EV in ISO and boosted later by +4 EV in processing look similar for noise and image quality as an image properly exposed in the camera (at ISO 800 here).

In my testing, even with frames underexposed by -5 EV, I did not see any of the banding effects (due to the phase-detect auto-focus pixels) reported by others. 

As such, I judge the Z6 to be an excellent camera for nightscape shooting when we often want to extract detail in the shadows or dark foregrounds. 


Compressed vs. Uncompressed / Raw Large vs. Small 

Comparison - Z6 Large vs Medium RAW
Comparing Z6 images shot at full resolution and at Medium Raw size. to show resolution and noise differences.

The Z6, as do many Nikons, offers a choice of shooting 12-bit or 14-bit raws, and either compressed or uncompressed. 

I shot all my test images as 14-bit uncompressed raws, yielding 46 megabyte files with a resolution of 6048 x 4024 pixels. So I cannot comment on how good 12-bit compressed files are compared to what I shot. Astrophotography demands the best original data. 

Z6 Menu - Raw Formats

However, as the menu above shows, Nikon now also offers the option of shooting smaller raw sizes. The Medium Raw setting produces an image 4528 x 3016 pixels and a 18 megabyte file (in the files I shot), but with all the benefits of raw files in processing.

Nikon with Card Slot copy
The Z cameras use the XQD style memory cards and in a single card slot. The fast XQDs are ideal for recording 4K movies at high data rates but are more costly than the more common SD cards.

The Medium Raw option might be attractive when shooting time-lapses, where you might need to fit as many frames onto the single XQD card as possible, yet still have images large enough for final 4K movies. 

However, comparing a Large Raw to a Medium Raw did show a loss of resolution, as expected, with little gain in noise reduction. 

This is not like “binning pixels” in CCD cameras to increase signal-to-noise ratio. I prefer to never throw away information in the camera, to allow the option of creating the best quality still images from time-lapse frames later. 

Nevertheless, it’s nice to see Nikon now offer this option on new models, a feature which has long been on Canon cameras. 


Star Image Quality

Orion Nebula, M42 and M43, with Nikon Z6
The Orion Nebula with the Nikon Z6

The Orion Nebula in Moonlight
The Orion Nebula with the Nikon D750

Above is the Orion Nebula with the D750 and with the Z6, both shot in moonlight with the same 105mm refractor telescope.

I did not find any evidence for “star-eating” that Sony mirrorless cameras have been accused of. (However, I did not find the Sony a7III guilty of eating stars either.) Star images looked as good in the Z6 as in the D750. 

M42 Blow-up in ACR
A single Orion Nebula image with the Z6 in a 600% blow-up in Adobe Camera Raw, showing clean artifact-free star images with good, natural colours.

Raw developers (Adobe, DxO, ON1, and others) decoded the Z6’s Bayer-array NEF files fine, with no artifacts such as oddly-coloured or misshapen stars, which can arise in cameras lacking an anti-alias filter. 


LENR Dark frames 

Z6 Dark Frame- No LENR
A blank long exposure with no LENR applied – click or tap to open the image full screen

Z6 Dark Frame-With LENR
A blank long exposure with LENR – tap or click to open the image full screen

Above, 8-minute exposures of nothing, taken with the lens cap on at room temperature: without LENR, and with LENR, both boosted a lot in brightness and contrast to exaggerate the visibility of any thermal noise. These show the reduction in noise speckling with LENR activated, and the clean result with the Z6. At small size you’ll likely see nothing but black!

For deep-sky imaging a common practice is to shoot “dark frames,” images recording just the thermal noise that can then be subtracted from the image. 

The Long Exposure Noise Reduction feature offered by all cameras performs this dark frame subtraction internally and automatically by the camera for any exposures over one second long. 

I tested the Z6’s LENR and found it worked well, doing the job to effectively reduce thermal noise (hot pixels) without adding any other artifacts. 

Z6 iMenu Screen
The rear screen “i” menu as I had it customized for my testing, with functions for astrophotography such as LENR assigned to the 12 boxes.

NOTE:

Some astrophotographers dismiss LENR and never use it. By contrast, I prefer to use LENR to do dark frame subtraction. Why? Through many comparison tests over the years I have found that separate dark frames taken later at night rarely do as good a job as LENR darks, because those separate darks are taken when the sensor temperature, and therefore the noise levels, are different than they were for the “light” frames. 

I’ve found that dark frames taken later, then subtracted “in post” inevitably show less or little effect compared to images taken with LENR darks. Or worse, they add a myriad of pock-mark black specks to the image, adding noise and making the image look worse.

The benefit of LENR is lower noise. The penalty of LENR is that each image takes twice as long to shoot — the length of the exposure + the length of the dark frame. Because …


As Expected on the Z6 … There’s no LENR Dark Frame Buffer

Only Canon full-frame cameras offer this little known but wonderful feature for astrophotography. Turn on LENR and it is possible to shoot three (with the Canon 6D MkII) or four (with the Canon 6D) raw images in quick succession even with LENR turned on. The Canon 5D series also has this feature. 

The single dark frame kicks in and locks up the camera only after the series of “light frames” are taken. This is excellent for taking a set of noise-reduced deep-sky images for later stacking without need for further “image calibration.” 

No Nikon has this dark frame buffer, not even the “astronomical” D810a. And not the Z6.

ANOTHER NOTE: 

I have to mention this every time I describe Canon’s dark frame buffer: It works only on full-frame Canons, and there’s no menu function to activate it. Just turn on LENR, fire the shutter, and when the first exposure is complete fire the shutter again. Then again for a third, and perhaps a fourth exposure. Only then does the LENR dark frame lock up the camera as “Busy” and prevent more exposures. That single dark frame gets applied to each of the previous “light” frames, greatly reducing the time it takes to shoot a set of dark-frame subtracted images. 

But do note that Canon’s dark frame buffer will not work if…:

a) You leave Live View on. Don’t do that for any long exposure shooting.

b) You control the camera through the USB port via external software. It works only when controlling the camera via its internal intervalometer or via the shutter port using a hardware intervalometer.


Sensor Illumination 

M35 with Z6 & Traveler (4 Minutes)
A single 4-minute exposure of Messier 35 in moonlight at ISO 400 with the Z6 and 105mm apo refractor, with no flat fielding or lens correction applied, showing the clean edges and lack of amp glows. The darkening of the corners is inherent in the telescope optical system and is not from the camera.

With DSLRs deep-sky images shot through telescopes, then boosted for contrast in processing, usually exhibit a darkening along the bottom of the frame. This is caused by the upraised mirror shadowing the sensor slightly, an effect never noticed in normal photography. 

Mirrorless cameras should be free of this mirror box shadowing. The Sony a7III, however, still exhibits some edge shadows due to an odd metal mask in front of the sensor. It shouldn’t be there and its edge darkening is a pain to eliminate in the final processing. 

As I show in my review of the a7III, the Sony also exhibits a purple edge glow in long-exposure deep-sky images, from an internal light source. That’s a serious detriment to its use in deep-sky imaging.

Happily, the Z6 proved to be free of any such artifacts. Images are clean and evenly illuminated to the edges, as they should be. I saw no amp glows or other oddities that can show up under astrophotography use. The Z6 can produce superb deep-sky images. 


Red Sensitivity

M97 with Z6 & Traveler (4 Minutes)
Messer 97 planetary nebula and Messier 108 galaxy in a lightly processed single 4-minute exposure at ISO 1600 with the 105mm refractor, again showing a clean field. The glow at top right is from a Big Dipper star just off the edge of the field.

During my short test period, I was not able to shoot red nebulas under moonless conditions. So I can’t say how well the Z6 performs for recording H-alpha regions compared to other “stock” cameras. 

However, I would not expect it to be any better, nor worse, than the competitors. Indeed, the stock Nikon D750 I have does a decent job at picking up red nebulas, though nowhere near as well as Nikon’s sadly discontinued D180a. See my blog post from 2015 for an example shot with that camera. 

With the D810a gone, if it is deep red nebulosity you are after with a Nikon, then consider buying a filter-modified Z6 or having yours modified. 

Both LifePixel and Spencer’s Camera offer to modify the Z6 and Z7 models. However, I have not used either of their services, so cannot vouch for them first hand. 


Live View Focusing and Framing 

Z6 Live View Screen
An image of the back of the camera with a scene under moonlight, with the Z6 set to the highest ISO speed in the movie mode, to aid framing the scene at night.

For all astrophotography manually focusing with Live View is essential. And with mirrorless cameras there is no optical viewfinder to look through to frame scenes. You are dependent on the live electronic image (on the rear LCD screen or in the eye-level electronic viewfinder, or EVF) for seeing anything.

Thankfully, the Z6 presents a bright Live View image making it easy to frame, find, and focus on stars. Maximum zoom for precise focusing is 15x, good but not as good as the D750’s 20x zoom level, but better than Canon’s 10x maximum zoom in Live View. 

The Z6 lacks the a7III’s wonderful Bright Monitoring function that temporarily ups the ISO to an extreme level, making it much easier to frame a dark night scene. However, something similar can be achieved with the Z6 by switching it temporarily to Movie mode, and having the ISO set to an extreme level.

As with most Nikons (and unlike Sonys), the Z6 remembers separate settings for the still and movie modes, making it easy to switch back and forth, in this case for a temporarily brightened Live View image to aid framing. 

That’s very handy, and the Z6 works better than the D750 in this regard, providing a brighter Live View image, even with the D750’s well-hidden Exposure Preview option turned on. 


Video Capability 

Comparison - Movie Noise Levels
Comparing the three cameras using 1/25-second still frames grabbed from moonlit night movies (HD with the D750 and 4K with the Z6 and a7III) shot at ISO 51200, plus a similarly exposed frame from the a7III shot with a shutter speed of only 1/4 second allowing the slower ISO of 8000.

Where the Z6 pulls far ahead of the otherwise similar D750 is in its movie features.

The Z6 can shoot 4K video (3840 x 2160 pixels) at either 30, 25, or 24 frames per second. Using 24 frames per second and increasing the ISO to between 12,800 to 51,200 (the Z6 can go as high as ISO 204,800!) it is possible to shoot real-time video at night, such as of auroras.

But the auroras will have to be bright, as at 24 fps, the maximum shutter speed is 1/25-second, as you might expect. 

The a7III, by comparison, can shoot 4K movies at “dragged” shutter speeds as slow as 1/4 second, even at 24 fps, making it possible to shoot auroras at lower and less noisy ISO speeds, albeit with some image jerkiness due to the longer exposures per frame. 

The D750 shoots only 1080 HD and, as shown above, produces very noisy movies at ISO 25,600 to 51,200. It’s barely usable for aurora videos.

The Z6 is much cleaner than the D750 at those high ISOs, no doubt due to far better internal processing of the movie frames. However, if night-sky 4K videos are an important goal, a camera from the Sony a7 series will be a better choice, if only because of the option for slower dragged shutter speeds.

For examples of real-time auroras shot with the Sony a7III see my music videos shot in Yellowknife and in Norway. 


Battery Life

Nikon Z6 Battery copy

The Z6 uses the EN-EL15b battery compatible with the battery and charger used for the D750. But the “b” variant allows for in-camera charging via the USB port. 

In room temperature tests the Z6 lasted for 1500 exposures, as many as the D750 was able to take in a side-by-side test. That was with the screens off.

At night, in winter temperatures of -10 degrees C (14° F), the Z6 lasted for three hours worth of continuous shooting, both for long deep-sky exposure sets and for a test time-lapse I shot, shown below. 

A time-lapse movie, downsized here to HD from the full-size originals, shot with the Z6 and its internal intervalometer, from twilight through to moonrise on a winter night. Processed with Camera Raw and LRTimelapse. 

However, with any mirrorless camera, you can extend battery life by minimizing use of the LCD screen and eye-level EVF. The Z6 has a handy and dedicated button for shutting off those screens when they aren’t needed during a shoot.

The days of mirrorless cameras needing a handful of batteries just to get through a few hours of shooting are gone. 


Lens and Telescope Compatibility 

Nikon with Sigma and FTZ copy
A 14mm Sigma Art lens with the Nikon FTZ lens adapter needed to attach any “legacy” F-mount lens to the Z6.

As with all mirrorless cameras, the Nikon Z cameras use a new lens mount, one that is incompatible with the decades-old Nikon F mount. 

The Z mount is wider and can accommodate wider-angle and faster lenses than the old F mount ever could, and in a smaller package. While we have yet to see those lenses appear, in theory that’s the good news.

The bad news is that you’ll need Nikon’s FTZ lens adapter to use any of your existing Nikon F-mount lenses on either the Z6 or Z7. As of this writing, Nikon is supplying an FTZ free with every Z body purchase. 

I got an FTZ with my loaner Z6 and it worked very well, allowing even third-party lenses like my Sigma Art lenses to focus at the same point as they normally do (not true of some thIrd-party adapters), preserving the lens’s optical performance. Autofocus functions all worked fine and fast.

Nikon with Scope Adapter and FTZ copy
The FTZ adapter needed to attach the Z6 to a telescope camera adapter (equipped with a standard Nikon T-ring) and field flattener lens for a refractor.

You’ll also need the FTZ adapter for use on a telescope, as shown above, to go from your telescope’s camera adapter, with its existing Nikon T-ring, to the Z6 body. 

T-rings are becoming available for the Z-mount, but even these third-party adapters are actually extension tubes, not just rings.

The reason is that the field flattener or coma corrector lenses often required with telescopes are designed to work best with the longer lens-to-sensor distance of a DSLR body. The FTZ adapter provides the necessary spacing, as do third-party adapters. 

Nikon Z6 FTZ Foot copy
The FTZ lens adapter has its own tripod foot, useful for balancing front-heavy lenses like the big Sigma here.

The only drawback to the FTZ is that any tripod plate attached to the camera body itself likely has to come off, and the tripod foot incorporated into the FTZ used instead. I found myself often having to swap locations for the tripod plate, an inconvenience. 


Camera Controller Compatibility 

Nikon with Ports copy
The port side of the Z6, with the DC2 shutter remote jack at bottom, and HDMI and USB-C ports above. There’s also a mic and headphone jack for video use.

Since it uses the same Nikon-type DC2 shutter port as the D750, the Z6 it should be compatible with most remote hardware releases and time-lapse motion controllers that operate a Nikon through the shutter port. An example are the controllers from SYRP.

On the other hand, time-lapse devices and external intervalometers that run Nikons through the USB port might need to have their firmware or apps updated to work with the Z6.

For example, as of early May 2019, CamRanger lists the Z6 as a supported camera; the Arsenal “smart controller” does not. Nor does Alpine Labs for their Radian and Pulse controllers, nor TimeLapse+ for its excellent View bramping intervalometer. Check with your supplier.

For those who like to use laptops to run their camera at the telescope, I found the Windows program Astro Photography Tool (v3.63) worked fine with the Z6, in this case connecting to the camera’s USB-C port using the USB-C to USB-A cable that comes with the camera. This allows APT to shift not only shutter speed, but also ISO and aperture under scripted sequences. 

However, BackyardNikon v2.0, current as of April 2019, does not list the Z6 as a supported camera. 


Raw File Compatibility 

Z6 Raw open in Raw Therapee
A Z6 Raw NEF file open in Raw Therapee 5.6, showing good star images and de-Bayering.

Inevitably, raw files from brand new cameras cannot be read by any raw developer programs other than the one supplied by the manufacturer, Nikon Capture NX in this case. However, even by the time I did my testing in winter 2019 all the major software suppliers had updated their programs to open Z6 files. 

Adobe Lightroom and Photoshop, Affinity Photo, DxO PhotoLab, Luminar 3, ON1 PhotoRAW, and the open-source Raw Therapee all open the Z6’s NEF raw files just fine. 

Z6 Raw in PixInsight
PixInsight 1.8.6 failing to open a Z6 raw NEF file.

Specialized programs for processing astronomy images might be another story. For example, as of v1.08.06, PixInsight, a favourite program among astrophotographers, does not open Z6 raw files. Nor does Nebulosity v4. But check with the developers for updates. 


Other Features for Astrophotography 

Here are other Nikon Z6 features I found of value for astrophotography, and for operating the camera at night. 

Nikon with Looking Right copy

Tilting LCD Screen 

Like the Nikon D750 and Sony A7III, the Z6 offers a tilting LCD screen great for use on a telescope or tripod when aimed up at the sky. However, the screen does not flip out and reverse, a feature useful for vloggers, but seldom needed for astrophotography. 

Nikon Z6 Top Screen copy
Showing the top OLED screen and dedicated ISO button that is easy to access in the dark. It works in conjunction with the top dial.

OLED Top Screen (Above)

The Sony doesn’t have one, and Canon’s low-cost mirrorless Rp also lacks one. But the top-mounted OLED screen of the Z6 is a great convenience for astrophotography. It makes it possible to monitor camera status and battery life during a shoot, even with the rear LCD screen turned off to prolong battery life.

Z6 Menu - Quick Menu

Touch Screen 

Sony’s implementation of touch-screen functions is limited to just choosing autofocus points. By contrast, the Nikon Z6 offers a full range of touchscreen functions, making it easy to navigate menus and choose settings. 

I do wish there was an option, as there is with Pentax, to tint the menus red for preserving night vision.

Z6 Menu - Intervalometer

Built-in Intervalometer

As with other Nikons, the Z6 offers an internal intervalometer capable of shooting time-lapses, just as long as individual exposures don’t need to be longer than 30 seconds. 

In addition, there’s the Exposure Smoothing option which, as I have found with the D750, is great for smoothing flickering in time-lapses shot using auto exposure. 

Sony has only just added an intervalometer to the a7III with their v3 firmware update, but with no exposure smoothing. 

Z6 Menu - Silent Shooting

Custom i Menu / Custom Function Buttons 

The Sony a7III has four custom function buttons users can assign to commonly used commands, for quick access. For example, I assign one Custom button to the Bright Monitoring function which is otherwise utterly hidden in the menus, but superb for framing nightscapes, if only you know it’s there! 

The Nikon Z6 has two custom buttons beside the lens mount. However, I found it easier to use the “i” menu (shown above) by populating it with those functions I use at night for astrophotography. It’s then easy to call them up and adjust them on the touch screen.

Thankfully, the Z6’s dedicated ISO button is now on top of the camera, making it much easier to find at night than the awkwardly placed ISO button on the back of the D750, which I am always mistaking for the Image Quality button, which you do not want to adjust by mistake. 

Nikon Z6-My Menu

My Menu 

As most cameras do, the Z6 also has a “My Menu” page which you can also populate with favourite menu commands. 

Nikon D750 and Z6 copy
The D750 (left) compared to the smaller and lighter Z6 (right). This shows the wider Z lens mount compared to Nikon’s old F-mount standard.

Lighter Weight / Smaller Size

The Z6 provides similar imaging performance, if not better (for movies) than the D750, and in a smaller and lighter camera, weighing 200 grams (0.44 pounds) less than the D750. Being able to downsize my equipment mass is a welcome plus to going mirrorless.

Comparison - Z6 Mech vs Silent Shutter
Extreme 800% blow-ups of the Moon show a slightly sharper image with the Z6 set to Silent Shutter.

Electronic Front Curtain Shutter / Silent Shooting 

By design, mirrorless cameras lack any vibration from a bouncing mirror. But even the mechanical shutter can impart vibration and blurring to high-magnification images taken through telescopes. 

The electronic front curtain shutter (lacking in the D750) helps eliminate this, while the Silent Shooting mode does just that — it makes the Z6 utterly quiet and vibration free when shooting, as all the shutter functions are now electronic. This is great for lunar and planetary imaging. 


What’s Missing for Astrophotography (not much!)

Bulb Timer for Long Exposures

While the Z6 has a Bulb setting, there is no Bulb Timer as there is with Canon’s recent cameras. A Bulb Timer would allow setting long Bulb exposures of any length in the camera, though Canon’s cannot be combined with the intervalometer. 

Instead, the Nikon must be used with an external Intervalometer for any exposures over 30 seconds long. Any number of units are compatible with the Z6, through its shutter port which is the same type DC2 jack used in the D750.

Z6 Menu - Multiple Exposures

In-Camera Image Stacking to Raws

The Z6 does offer the ability to stack up to 10 images in the camera, a feature also offered by Canon and Pentax. Images can be blended with a Lighten (for star trails) or Average (for noise smoothing) mode. 

However, unlike with Canon and Pentax, the result is a compressed JPG not a raw file, making this feature of little value for serious imaging. Plus with a maximum of only 10 exposures of up to 30-seconds each, the ability to stack star trails “in camera” is limited. 

Illuminated Buttons 

Unlike the top-end D850, the Z6’s buttons are not illuminated, but then again neither are the Z7’s.


As a bonus — the Nikon 35mm S-Series Lens

Nikkor 35mm Lens Test
The upper left frame corner of a tracked star image shot with the 35mm S lens wide open at f/1.8 and stopped down at third stop increments.

With the Z6 I also received a Nikkor 35mm f/1.8 S lens made for the Z-mount, as the lens perhaps best suited for nightscape imaging out of the native Z-mount lenses from Nikon. See Nikon’s website for the listing. 

If there’s a downside to the Z-series Nikons it’s the limited number of native lenses that are available now from Nikon, and likely in the future from anyone, due to Nikon not making it easy for other lens companies to design for the new Z mount. 

In testing the 35mm Nikkor on tracked shots, stars showed excellent on- and off-axis image quality, even wide open at f/1.8. Coma, astigmatism, spherical aberration, and lateral chromatic aberration were all well controlled. 

However, as with most lenses now offered for mirrorless cameras, the focus is “by-wire” using a ring that doesn’t mechanically adjust the focus. As a result, the focus ring turns continuously and lacks a focus scale. 

So it is not possible to manually preset the lens to an infinity mark, as nightscape photographers often like to do. Focusing must be done each night. 

Until there is a greater selection of native lenses for the Z cameras, astrophotographers will need to use the FTZ adapter and their existing Nikon F-mount or third-party Nikon-mount lenses with the Zs.


Recommendations 

I was impressed with the Z6. 

The Owl Nebula and Messier 108 Galaxy
The Owl Nebula, Messier 97, a planetary nebula in our galaxy, and the edge-on spiral galaxy Messier 108, paired below the Bowl of the Big Dipper in Ursa Major. This is a stack of 5 x 4-minute exposures at ISO 1600 with the Nikon Z6 taken as part of testing. This was through the Astro-Physics Traveler refractor at f/6 with the Hotech field flattener and FTZ adapter.

For any owner of a Nikon cropped-frame DSLR (from the 3000, 5000, or 7000 series for example) wanting to upgrade to full-frame for astrophotography I would suggest moving to the Z6 over choosing a current DSLR. 

Mirrorless is the way of the future. And the Z6 will yield lower noise than most, if not all, of Nikon’s cropped-frame cameras.

Nikkor 35mm S Lens copy
The Z6 with the Nikkor 35mm f/1.8 S lens native for the Z mount.

For owners of current Nikon DSLRs, especially a 24-megapixel camera such as the D750, moving to a Z6 will not provide a significant improvement in image quality for still images. 

But … it will provide 4K video and much better low-light video performance than older DSLRs. So if it is aurora videos you are after, the Z6 will work well, though not quite as well as a Sony alpha. 

In all, there’s little downside to the Z6 for astrophotography, and some significant advantages: low noise, bright live view, clean artifact-free sensor images, touchscreen convenience, silent shooting, low-light 4K video, all in a lighter weight body than most full-frame DSLRs. 

I highly recommend the Nikon Z6. 

— Alan, April 30, 2019 / © 2019 Alan Dyer / AmazingSky.com 

 

 

Shooting Moonstrikes at Dinosaur Park


Moonlight at Dino Park Title

It was a magical night as the rising Moon lit the Badlands with a golden glow.

When doing nightscape photography it’s often best not to fight the Moon, but to embrace it and use it as your light source.

I did this on a fine night, Easter Sunday, at one of my favourite nightscape spots, Dinosaur Provincial Park.

I set up two cameras to frame different views of the hoodoos as they lit up with the light of the rising waning Moon.

The night started out as a dark moonless evening as twilight ended. Then about 90 minutes after the arrival of darkness, the sky began to brighten again as the Moon rose to illuminate the eroded formations of the Park.

Moonrise Light at Dinosaur Park - West
The formations of Dinosaur Provincial Park, Alberta, lit by the rising gibbous Moon, off camera at left, on April 21/22, 2019. This is looking west, with the stars of the winter sky setting. Procyon is at right. Aphard in Hydra is above the hill. This is a stack of 8 exposures, mean combined to smooth noise, for the ground, and a single exposure for the sky, all with the 24mm Sigma Art lens at f/5.6 and Nikon D750 at ISO 6400, each for 25 seconds. The images were from the end of a sequence shot for a time-lapse using the TimeLapse+ View intervaolometer. 

This was a fine example of “bronze hour” illumination, as some have aptly called it.

Photographers know about the “golden hour,” the time just before sunset or just after sunrise when the low Sun lights the landscape with a golden glow.

The Moon does the same thing, with a similar tone, though greatly reduced in intensity.

The low Moon, especially just after Full, casts a yellow or golden tint over the scene. This is caused by our atmosphere absorbing the “cold” blue wavelengths of moonlight, and letting through the “warm” red and yellow tones.

Making use of the rising (or setting) Moon to light a scene is one way to capture a nightscape lit naturally, and not with artificial lights, which are increasingly being frowned upon, if not banned at popular nightscape destinations.

StarryNightImage
A screen shot from the desktop app Starry Night (by Simulation Curriculum) showing the waning gibbous Moon rising in the SE on April 21. Such “planetarium” apps are useful for simulating the sky of a planned shoot.

“Bronze hour” lighting is great in still-image nightscapes. But in time-lapses the effect is more striking — indeed, in time-lapse lingo it is called a “moonstrike” scene.

The dark landscape suddenly lights up as if it were dawn, yet stars remain in the sky.

IMG_4579
A screen shot of a planning app that is a favourite of mine, The Photographer’s Ephemeris, set up to show the scene for moonrise on April 21 from the Park.

The best nights for such a moonstrike are ones with a waning gibbous or last quarter Moon. At these phases the Moon rises after sunset, to re-light a scene after evening twilight has faded.

On April 21 I made use of such a circumstance to shoot moonstrike stills and movies, not only for their own sake, but for use as illustrations in the next edition of my Nightscapes and Time-lapse eBook (at top here).

TimeLapse+View-Day Interval

One camera, the Nikon D750, I coupled with a device called a bramping intervalometer, in this case the TimeLapse+ View, shown above. It works great to automatically shift the shutter and ISO speeds as the sky darkens then brightens again.

Yes, in bright situations the camera’s own Auto Exposure and Auto ISO modes might accomplish this.

But … once the sky gets dark the Auto circuits fail and you’re left with hugely underexposed images.

The TimeLapse+ View, with its more sensitive built-in light meter, can track right through into full darkness, making it possible to shoot so-called “holy grail” time-lapses that go from daylight to darkness, from sunset to the Milky Way, all shot unattended.

Moonrise Light at Dinosaur Park - North
The eroding formations of Dinosaur Provincial Park, Alberta, lit by the rising gibbous Moon, off camera at right, on April 21/22, 2019. This is looking north, with Polaris at upper centre, Capella setting at left, Vega rising at right, and the W of Cassiopeia at lower centre. This is a stack of 8 exposures, mean combined to smooth noise, for the ground, and one exposure from that set for the sky. All with the 15mm Laowa lens at f/2.8 and Sony a7III at ISO 3200, each for 30 seconds.  

For the other camera, the Sony a7III (with the Laowa 15mm lens I just reviewed) I set the camera manually, then shifted the ISO and shutter speed a couple of times to accommodate the darkening, then brightening of the scene.

Processing the resulting RAW files in the highly-recommended program LRTimelapse smoothed out all the jumps in brightness to make a seamless transition.

I also used the new intervalometer function that Sony has just added to the a7III with its latest firmware update. Hurray! I complained about the lack of an intervalometer in my original review of the Sony a7III. But that’s been fixed.

Moonrise Star Trails at Dinosaur Park
This is looking north, with the stars of the northern sky pivoting around Polaris. This is a stack of 8 exposures, mean combined to smooth noise, for the ground, and 250 exposures for the sky, blended with Lighten mode to create the stails. However, I used the Advanced Stacker Plus actions in Photoshop to do the stacking, creating the tapering effect in the process. All exposures with the 15mm Laowa lens at f/2.8 and Sony a7III at ISO 3200, each for 30 seconds. 

I shot 425 frames with the Sony, which I not only turned into a movie but, as one can with time-lapse frames, I also stacked into a star trail still image, in this case looking north to the circumpolar stars.

To do the stacking I used the Advanced Stacker Plus actions for Photoshop, developed and sold by StarCircleAcademy.

I prefer this action set over dedicated programs such as StarStaX, because it works directly with the developed Raw files. There’s no need to create a set of JPGs to stack, compromising image quality, and departing from the non-destructive workflow I prefer to maintain.

While the still images are very nice, the intended final result was this movie above, a short time-lapse vignette using clips from both cameras. Do watch in HD.

I rendered out the frames from the Sony both as a “normal” time-lapse, and as one with accumulating star trails, again using the Advanced Stacker Plus actions to create the intermediate frames for assembling into the movie.

All these techniques, gear, and apps are explained in tutorials in my eBook, above. However, it’s always great to get a night perfect for putting the methods to work on a real scene.

— Alan, April 27, 2019 / © 2019 Alan Dyer / AmazingSky.com

 

Testing the Venus Optics 15mm Lens


Laowa Test Title

I test out a fast and very wide lens designed specifically for Sony mirrorless cameras. 

In a previous test I presented results on how well the Sony a7III mirrorless camera performs for nightscape and deep-sky photography. It works very well indeed.

But what about lenses for the Sony? Here’s one ideal for astrophotography.


TL;DR Conclusions

Made for Sony e-mount cameras, the Venus Optics 15mm f/2 Laowa provides excellent on- and off-axis performance in a fast and compact lens ideal for nightscape, time-lapse, and wide-field tracked astrophotography with Sony mirrorless cameras. (UPDATE: Venus Optics has announced versions of this lens for Canon R and Nikon Z mount mirrorless cameras.)

I use it a lot and highly recommend it.


Size and Weight

While I often use the a7III with my Canon lenses by way of a Metabones adapter, the Sony really comes into its own when matched to a “native” lens made for the Sony e-mount. The selection of fast, wide lenses from Sony itself is limited, with the new Sony 24mm G-Master a popular favourite (I have yet to try it).

However, for much of my nightscape shooting, and certainly for auroras, I prefer lenses even wider than 24mm, and the faster the better.

Auroral Swirls over Båtsfjord, Norway Aurora over Båtsfjord, Norway. This is a single 0.8-second exposure at f/2 with the 15mm Venus Optics lens and Sony a7III at ISO 1600.

The Laowa 15mm f/2 from Venus Optics fills the bill very nicely, providing excellent speed in a compact lens. While wide, the Laowa is a rectilinear lens providing straight horizons even when aimed up, as shown above. This is not a fish-eye lens.

Laowa 15mm Front View with Filter Though a very wide lens, the 15mm Laowa accepts standard 72mm filters. The metal lens hood is removable. © 2019 Alan Dyer

The Venus Optics 15mm realizes the potential of mirrorless cameras and their short flange distance that allows the design of fast, wide lenses without massive bulk.

Sigma 14mm vs Laowa 15mm Sigma 14mm f/1.8 Art lens (for Nikon mount) vs. Venus Optics 15mm f/2 lens (for Sony mount). © 2019 Alan Dyer

While compact, at 600 grams the Laowa 15mm is quite hefty for its size due to its solid metal construction. Nevertheless, it is half the weight of the massive 1250-gram Sigma 14mm f/1.8 Art. The Laowa is not a plastic entry-level lens, nor is it cheap, at $850 from U.S. sources.

For me, the Sony-Laowa combination is my first choice for a lightweight travel camera for overseas aurora trips

Laowa 15mm Back View The lens mount showing no electrical contacts to transfer lens metadata to the camera. © 2019 Alan Dyer

However, this is a no-frills manual focus lens. Nor does it even transfer aperture data to the camera, which is a pity. There are no electrical connections between the lens and camera.

However, for nightscape work where all settings are adjusted manually, the Venus Optics 15mm works just fine. The key factor is how good are the optics. I’m happy to report that they are very good indeed.


Testing Under the Stars

To test the Venus Optics lens I shot “same night” images, all tracked, with the Sigma 14mm f/1.8 Art lens, at left, and the Rokinon 14mm SP (labeled as being f/2.4, at right). Both are much larger lenses, made for DSLRs, with bulbous front elements not able to accept filters. But they are both superb lenses. See my test report on these lenses published in 2018.

Sigma and Rokinon 14mm The Sigma 14mm f/1.8 Art lens (left) vs. the Rokinon SP 14mm f/2.4. © 2019 Alan Dyer

The next images show blow-ups of the same scene (the nightscape shown in full below, taken at Dinosaur Provincial Park, Alberta), and all taken on a tracker.

I used the Rokinon on the Sony a7III using the Metabones adapter which, unlike some brands of lens adapters, does not compromise the optical quality of the lens by shifting its focal position. But lacking a lens adapter for Nikon-to-Sony at the time of testing, I used the Nikon-mount Sigma lens on a Nikon D750, a DSLR camera with nearly identical sensor specs to the Sony.


Vignetting

Laowa 15mm @ f2 A tracked image with the Venus Optics Laowa 15mm at f/2. Click or tap on an image to download a full-resolution JPG for closer inspection.

Above is a tracked image (so the stars are not trailed, which would make it hard to tell aberrations from trails), taken wide open at f/2. No lens correction has been applied so the vignetting (the darkening of the frame corners) is as the lens provides.

As shown above, when used wide open at f/2 vignetting is significant, but not much more so than with competitive lenses with much larger lenses, as I compare below.

And the vignetting is correctable in processing. Adobe Camera Raw and Lightroom have this lens in their lens profile database. That’s not the case with current versions (as of April 2019) of other raw developers such as DxO PhotoLab, ON1 Photo RAW, and Raw Therapee where vignetting corrections have to be dialled in manually by eye.

Laowa 15mm @ f2.8 A tracked image with the Venus Optics Laowa 15mm stopped down 1 stop to f/2.8.

When stopped down to f/2.8 the Laowa “flattens” out a lot for vignetting and uniformity of frame illumination. Corner aberrations also improve but are still present. I show those in close-up detail below.

Lens Comparison - Vignetting 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the left side of the image for vignetting (light fall-off), wide open and stopped down. ©2018 Alan Dyer

Above, I compare the vignetting of the three lenses, both wide open and when stopped down. Wide open, all the lenses, even the Sigma and Rokinon despite their large front elements, show quite a bit of drop off in illumination at the corners.

The Rokinon SP actually seems to be the worst of the trio, showing some residual vignetting even at f/2.8, while it is reduced significantly in the Laowa and Sigma lenses. Oddly, the Rokinon SP, even though it is labeled as f/2.4, seemed to open to f/2.2, at least as indicated by the aperture metadata.


On-Axis Performance

Lens Comparison - Centre 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the centre of the image for sharpness, wide open and stopped down. Click or tap on an image to download a full-resolution JPG for closer inspection. © 2018 Alan Dyer

Above I show lens sharpness on-axis, both wide open and stopped down, to check for spherical and chromatic aberrations with the bright blue star Vega centered. The red box in the Navigator window at top right indicates what portion of the frame I am showing, at 200% magnification in Photoshop.

On-axis, the Venus Optics 15mm shows stars just as sharply as the premium Sigma and Rokinon lenses, with no sign of blurring spherical aberration nor coloured haloes from chromatic aberration.

Laowa 15mm Side with Focus Point This is where this lens reaches sharpest focus on stars, just shy of the Infinity mark. © 2019 Alan Dyer

Focusing is precise and easy to achieve with the Sony on Live View. My unit reaches sharpest focus on stars with the lens set just shy of the middle of the infinity symbol. This  is consistent and allows me to preset focus just by dialing the focus ring, handy for shooting auroras at -35° C, when I prefer to minimize fussing with camera settings, thank you very much!


Off-Axis Performance

Lens Comparison - Upper Left 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the centre of the image for sharpness, wide open and stopped down. Click or tap on an image to download a full-resolution JPG for closer inspection. © 2018 Alan Dyer
Lens Comparison - Upper Right 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the upper right corner of the image for aberrations, wide open and stopped down. © 2018 Alan Dyer

The Laowa and Sigma lenses show similar levels of off-axis coma and astigmatism, with the Laowa exhibiting slightly more lateral chromatic aberration than the Sigma. Both improve a lot when stopped down one stop, but aberrations are still present though to a lesser degree.

However, I find that the Laowa 15mm performs as well as the Sigma 14mm Art for star quality on- and off-axis. And that’s a high standard to match.

The Rokinon SP is the worst of the trio, showing significant elongation of off-axis star images (they look like lines aimed at the frame centre), likely due to astigmatism. With the 14mm SP, this aberration was still present at f/2.8, and was worse at the upper right corner than at the upper left corner, an indication to me that even the premium Rokinon SP lens exhibits slight lens de-centering, an issue users have often found with other Rokinon lenses.


Real-World Examples – The Milky Way

Sweep of the Autumn Milky Way This is a stack of 8 x 2-minute exposures with the Venus Optics Laowa 15mm lens at f/2 and Sony a7III at ISO 800, on the Sky-Watcher Star Adventurer tracker. A single exposure taken through the Kenko Softon A filter layered in with Lighten mode adds the star glows, though exaggerates the lens distortion on the bright stars.
Mars and the Milky Way over Writing-on-Stone This is a stack of 12 exposures for the ground, mean combined to smooth noise, and one exposure for the sky, all 30 seconds at f/2 with the Laowa 15mm lens on the Sony a7III camera at ISO 6400. These were the last frames in a 340-frame time-lapse sequence.

The fast speed of the Laowa 15mm is ideal for shooting tracked wide-field images of the Milky Way, and untracked camera-on-tripod nightscapes and time-lapses of the Milky Way.

Image aberrations are very acceptable at f/2, a speed that allows shutter speed and ISO to be kept lower for minimal star trailing and noise while ensuring a well-exposed frame.


Real World Examples – Auroras

Coloured Curtains over CNSC (Feb 9, 2019) Aurora over the Churchill Northern Studies Centre, Churchill, Manitoba. This is 6 seconds at f/2 with the 15mm Venus Optic lens and Sony a7III at ISO 3200.
Sky-Filling Aurora at Tibbitt Lake Aurora from near Yellowknife, NWT, September 8, 2018. This is 2.5-seconds at f/2 with the Venus Optics 15mm lens and Sony a7IIII at ISO 3200.
Aurora from at Sea Near Lofotens #1 The Northern Lights from at sea when leaving the Lofoten Islands, Norway heading toward the mainlaind, from Stamsund to Bodo, March 3, 2019. This was from the Hurtigruten ship the ms Trollfjord. This is a single 1-second exposure for at f/2 with the 15mm Venus Optics lens and Sony a7III at ISO 6400.

Where the Laowa 15mm really shines is for auroras. On my trips to chase the Northern Lights I often take nothing but the Sony-Laowa pair, to keep weight and size down.

Above is an example, taken from a moving ship off the coast of Norway. The fast f/2 speed (I wish it were even faster!) makes it possible to capture the Lights in only 1- or 2-second exposures, albeit at ISO 6400. But the fast shutter speed is needed for minimizing ship movement.


Video Links

The Sony also excels at real-time 4K video, able to shoot at ISO 12,800 to 51,200 without excessive noise.

Aurora Reflections from Alan Dyer on Vimeo.

The Sky is Dancing from Alan Dyer on Vimeo.

The Northern Lights At Sea from Alan Dyer on Vimeo.

Examples of my aurora videos shot with the Sony and Venus Optics 15mm lens are in previous blogs from Yellowknife, NWT in September 2018, from Churchill, Manitoba in February 2019, and from at sea in Norway in March 2019.

Click through to see the posts and the videos shot with the Venus Optics 15mm.

As an aid to video use, the aperture ring of the Venus Optics 15mm can be “de-clicked” at the flick of a switch, allowing users to smoothly adjust the iris during shooting, avoiding audible clicks and jumps in brightness. That’s a very nice feature indeed.

In all, I can recommend the Venus Optics Laowa 15mm lens as a great match to Sony mirrorless cameras, for nightscape still and video shooting. UPDATE: Versions for Canon R and Nikon Z mount mirrorless cameras will now be available.

— Alan, April 20, 2019 / © 2019 Alan Dyer / AmazingSky.com

Testing ON1 Photo RAW for Astrophotography


ON1 Testing Title

Can the new version of ON1 Photo RAW match Photoshop for astrophotography? 

The short TL;DR answer: No.

But … as always, it depends. So do read on.


Released in mid-November 2018, the latest version of ON1 Photo RAW greatly improves a non-destructive workflow. Combining Browsing, Cataloging, Raw Developing, with newly improved Layers capabilities, ON1 is out to compete with Adobe’s Creative Cloud photo suite – Lightroom, Camera Raw, Bridge, and Photoshop – for those looking for a non-subscription alternative.

Many reviewers love the new ON1 – for “normal” photography.

But can it replace Adobe for night sky photos? I put ON1 Photo RAW 2019 through its paces for the demanding tasks of processing nightscapes, time-lapses, and deep-sky astrophotos.


The Conclusions

In my eBook “How to Photograph and Process Nightscapes and Time-Lapses” (linked to at right) I present dozens of processing tutorials, including several on how to use ON1 Photo RAW, but the 2018 edition. I was critical of many aspects of the old version, primarily of its destructive workflow when going from its Develop and Effects modules to the limited Layers module of the 2018 edition.

I’m glad to see many of the shortfalls have been addressed, with the 2019 edition offering a much better workflow allowing layering of raw images while maintaining access to all the original raw settings and adjustments. You no longer have to flatten and commit to image settings to layer them for composites. When working with Layers you are no longer locked out of key functions such as cropping.

I won’t detail all the changes to ON1 2019 but they are significant and welcome.

The question I had was: Are they enough for high-quality astrophotos in a non-destructive workflow, Adobe Photoshop’s forté.

While ON1 Photo RAW 2019 is much better, I concluded it still isn’t a full replacement of Adobe’s Creative Cloud suite, as least not for astrophotography.

NOTE: All images can be downloaded as high-res versions for closer inspection. 


ON1 2019 is Better, But for Astrophotography …

  1. Functions in Layers are still limited. For example, there is no stacking and averaging for noise smoothing. Affinity Photo has those.
  2. Filters, though abundant for artistic special effect “looks,” are limited in basic but essential functions. There is no Median filter, for one.
  3. Despite a proliferation of contrast controls, for deep-sky images (nebulas and galaxies) I was still not able to achieve the quality of images I’ve been used to with Photoshop.
  4. The lack of support for third-party plug-ins means ON1 cannot work with essential time-lapse programs such as Timelapse Workflow or LRTimelapse.

ON1 Final Composite
A finished nightscape composite, with stacked exposures for the ground and stacked and tracked exposures for the sky, layered and blended in ON1.


Recommendations

Nightscapes: ON1 Photo RAW 2019 works acceptably well for nightscape still images:

  1. Its improved layering and excellent masking functions are great for blending separate ground and sky images, or for applying masked adjustments to selected areas.

Time-Lapses: ON1 works is just adequate for basic time-lapse processing:

  1. Yes, you can develop one image and apply its settings to hundreds of images in a set, then export them for assembly into a movie. But there is no way to vary those settings over time, as you can by mating Lightroom to LRTimelapse.
  2. As with the 2018 edition, you still cannot copy and paste masked local adjustments from image to image, limiting their use.
  3. Exporting those images is slow.

Deep-Sky: ON1 is not a program I can recommend for deep-sky image processing:

  1. Stars inevitably end up with unsightly sharpening haloes.
  2. De-Bayering artifacts add blocky textures to the sky background.
  3. And all the contrast controls still don’t provide the “snap” and quality I’m used to with Photoshop when working with low-contrast subjects.

Library / Browse Functions

ON1 Browse Module
ON1 cannot catalog or display movie files or Photoshop’s PSB files (but then again with PSBs neither can Lightroom!).

ON1 is sold first and foremost as a replacement for Adobe Lightroom, and to that extent it can work well. Unlike Lightroom, ON1 allows browsing and working on images without having to import them formally into a catalog.

However, you can create a catalog if you wish, one that can be viewed even if the original images are not “on-line.” The mystery seems to be where ON1 puts its catalog file on your hard drive. I was not able to find it, to manually back it up. Other programs, such as Lightroom and Capture One, locate their catalogs out in the open in the Pictures folder.

For those really wanting a divorce from Adobe, ON1 now offers an intelligent AI-based function for importing Lightroom catalogs and transferring all your Lightroom settings you’ve applied to raw files to ON1’s equivalent controls.

However, while ON1 can read Photoshop PSD files, it will flatten them, so you would lose access to all the original image layers.

ON1’s Browse module is good, with many of the same functions as Lightroom, such as “smart collections.” Affinity Photo – perhaps ON1’s closest competitor as a Photoshop replacement – still lacks anything like it.

But I found ON1’s Browse module buggy, often taking a long while to allow access into a folder, presumably while it is rendering image previews.

There are no plug-ins or extensions for exporting directly to or synching to social media and photo sharing sites.


Nightscape Processing – Developing Raw Images

ON1 Before and After Processing
On the left, a raw image as it came out of the camera. On the right, after developing (with Develop and Effects module settings applied) in ON1.

For this test I used the same nightscape image I threw at Adobe competitors a year ago, in a test of a dozen or more raw developers. It is a 2-minute tracked exposure with a Sigma 20mm Art lens at f/2 and Nikon D750 at ISO 1600.

ON1 did a fairly good job. Some of its special effect filters, such a Dynamic Contrast, Glow, and Sunshine, can help bring out the Milky Way, though do add an artistic “look” to an image which you might or might not like.

Below, I compare Adobe Camera Raw (ACR) to ON1. It was tough to get ON1’s image looking the same as ACR’s result, but then again, perhaps that’s not the point. Does it just look good? Yes, it does.

ON1 & ACR Raw Image Comparison
On the left, a single raw image developed with Adobe Camera Raw. On the right, the same image with ON1 and its basic Develop and more advanced Effects settings.

Compared to Adobe Camera Raw, which has a good array of basic settings, ON1 has most of those and more, in the form of many special Effects, with many combined as one-click Presets, as shown below.

ON1 Presets
ON1 offers a huge array of Presets that apply combinations of its filters with one click from the Browse module.

A few presets and individual filters – the aforementioned Dynamic Contrast and Glow – are valuable. However, most of ON1’s filters and presets will not be useful for astrophotography, unless you are after highly artistic and unnatural effects.

Noise Reduction and Lens Correction

ON1 Noise Reduction
On the left, an image in ON1 without any Noise Reduction. On the right, with noise reduction and sharpening (under Details) applied with the settings shown.

Critical to all astrophotography is excellent noise reduction. ON1 does a fine job here, with good smoothing of noise without harming details.

Lens Correction works OK. It detected the 20mm Sigma art lens and automatically applied distortion correction, but not any vignetting (light “fall-off”) correction, perhaps the most important correction in nightscape work. You have to dial this in manually by eye, a major deficiency.

By comparison, ACR applies both distortion and vignetting correction automatically. It also includes settings for many manual lenses that you can select and apply in a click. For example, ACR (and Lightroom) includes settings for popular Rokinon and Venus Optics manual lenses; ON1 does not.

Hot Pixel Removal

Hot Pixel Removal Comparison
On the left, ACR with noise reduction applied (it offers no user-selectable Hot Pixel Removal tool). In the middle, ON1 with Remove Hot Pixels turned on; on the right, with it turned off – showing more hot pixels than ACR does.

I shot the example image on a warm summer night and without using in-camera Long Exposure Noise Reduction (to keep the gap between exposures short when shooting sets of tracked and untracked exposures for later compositing).

However, the penalty for not using LENR to expedite the image taking is a ground filled with hot pixels. While Adobe Camera Raw does have some level of hot pixel removal working “under the hood,” many specks remained.

ON1 showed more hot pixels, until you clicked Remove Hot Pixels, found under Details. As shown at centre above, it did a decent job getting rid of the worst offenders.

But as I’ll show later, the penalty is that stars now look distorted and sometimes double, or you get the outright removal of stars. ON1 doesn’t do a good job distinguishing between true sharp-edged hot pixels and the softer images of stars. Indeed, it tends to over sharpen stars.

A competitor, Capture One 11, does a better job, with an adjustable Single Pixel removal slider, so you can at least select the level of star loss you are willing to tolerate to get rid of hot pixels.

Star Image Quality

ON1 & ACR Star Image Comparison
On the left, a 700% blow-up of the stars in Adobe Camera Raw. On the right, the same image processed in ON1 and exported out as a PSD.

Yes, we are pixel peeping here, but that’s what we do in astrophotography. A lot!

Stars in ON1 don’t look as good as in Camera Raw. Inevitably, as you add contrast enhancements, stars in ON1 start to exhibit dark and unsightly “sharpening haloes” not present in ACR, despite me applying similar levels of sharpening and contrast boosts to each version of the image.

Camera Raw has been accused of producing images that are not as sharp as with other programs such as Capture One and ON1.

There’s a reason. Other programs over-sharpen, and it shows here.

We can get away with it here in wide-field images, but not later with deep-sky close-ups. I don’t like it. And it is unavoidable. The haloes are there, albeit at a low level, even with no sharpening or contrast enhancements applied, and no matter what image profile is selected (I used ON1 Standard throughout).

De-Bayering Artifacts

ON1-Debayer
ON1, with contrast boosts applied but with no sharpening or noise reduction, shows star haloes, while the sky shows a blocky pattern at the pixel level in high ISO shots.

ACR-Debayer
Adobe Camera Raw, with similar settings but also no sharpening or noise reduction, shows a smooth and uniform sky background.

You might have to download and closely inspect these images to see the effect, but ON1’s de-Bayering routine exhibits a cross-hatched blocky pattern at the pixel-peeping level. ACR does not.

I see this same effect with some other raw developers. For example, the free Raw Therapee shows it with many of its choices for de-Bayering algorithms, but not all. Of the more than a dozen raw developers I tested a year ago, ACR and DxO PhotoLab had (and still have) the most artifact-free de-Bayering and smoothest noise reduction

Again, we can get away with some pixel-level artifacts here, but not later, in deep-sky processing.


Nightscape Processing — Layering and Compositing

ON1 Perfect Brush
ON1’s adjustable “Perfect Brush” option for precise masking around edges and objects isn’t quite as effective as Photoshop’s Quick Selection Tool.

Compositing

The 2018 version of ON1 forced you to destructively flatten images when bringing them into the Layers module.

The 2019 version of ON1 improves that. It is now possible to composite several raw files into one image and still retain all the original Develop and Effects settings for non-destructive work.

You can then use a range of masking tools to mask in or out the sky.

For the example above, I have stacked tracked and untracked exposures, and am starting to mask out the trailed stars from the untracked exposure layer.

To do this with Adobe, you would have to open the developed raw files in Photoshop (ideally using “smart objects” to retain the link back to the raw files). But with ON1 we stay within the same program, to retain access to non-destructive settings. Very nice!

To add masks, ON1 2019 does not have the equivalent of Photoshop’s excellent Quick Selection Tool for selecting the sky or ground. It does have a “Perfect Brush” option which uses the tonal value of the pixels below it, rather than detecting edges, to avoid “painting over the lines.”

While the Perfect Brush does a decent job, it still requires a lot of hand painting to create an accurate mask without holes and defects. There is no non-destructive “Select and Mask” refinement option as in Photoshop.

Yes, ON1’s Refine Brush and Chisel Mask tools can help clean up a mask edge but are destructive to the mask. That’s not acceptable to my non-destructive mindset!

Local Adjustments 

ON1 Masking Adjustments
Local Adjustments can be painted in or out with classic and easy-to-adjust and view masks and layers, rather than adjustment pins used by many raw developers such as ACR.

The masking tools are also applicable to adding “Local Adjustments” to any image layer, to brighten or darken regions of an image for example.

These work well and I find them more intuitive than the “pins” ACR uses on raw files, or DxO PhotoLab’s quirky “U-Point” interface.

ON1’s Local Adjustments work more like Photoshop’s Adjustment Layers and are similarly non-destructive. Excellent.

Luminosity Masks

ON1 Luminosity Masking
ON1 has one-click Luminosity masking, an excellent feature.

A very powerful feature of ON1 is its built-in Luminosity masking.

Yes, Camera Raw now has Range Masks, and Photoshop can be used to create luminosity masks, but making Photoshop’s luminosity masks easily adjustable requires purchasing third-party extension panels.

ON1 can create an adjustable and non-destructive luminosity mask on any image or adjustment layer with a click.

While such masks, based on the brightness of areas, aren’t so useful for low-contrast images like the Milky Way scene above, they can be very powerful for merging high-contrast images (though ON1 also has an HDR function not tested here).

Glow Effect
ON1’s handy Orton-style Glow effect, here with a Luminosity mask applied. The mask can be adjusted with the Levels and Window sliders, and applied to a range of colors as well.

ON1 has the advantage here. Its Luminosity masks are a great feature for compositing exposures or for working on regions of bright and dark in an image.

Final Composite

ON1 Final Composite
A finished nightscape composite, with stacked exposures for the ground and stacked and tracked exposures for the sky, layered and blended in ON1.

Here again is the final result, above.

It is not just one image each for the sky and ground, but is instead a stack of four images for each half of the composite, to smooth noise. This form of stacking is somewhat unique to astrophotography, and is commonly used to reduce noise in nightscapes and in deep-sky images, as shown later.

Stacking

ON1-Layer Opacities
This shows an intermediate step in creating the final composite shown above: Four sky layers are stacked, with opacities as shown, which has the effect of smoothing noise. But to continue working on the image requires making a single “New Stamped Layer” out of the group of four – in this case, the sky layers. The same can be done for the four ground layers.

Here I show how you have to stack images in ON1.

Unlike Photoshop and Affinity Photo, ON1 does not have the ability to merge images automatically into a stack and apply a mathematical averaging to the stack, usually a Mean or Median stack mode. The averaging of the image content is what reduces the random noise.

Instead, with ON1 you have perform an “old school” method of average stacking – by changing the opacity of the layers, so that Layer 2 = 50%, Layer 3 = 33%, Layer 4 = 25%, and so on. The result is identical to performing a Mean stack mode in Photoshop or Affinity.

Fine, except there is no way to perform a Median stack, which can be helpful for eliminating odd elements present in only one frame, perhaps an aircraft trail.

Copy and Paste Settings

ON1 Pasting Settings
ON1 allows easy copying and pasting of settings from one raw image to others, with the annoying exception of Local Adjustments and their masks.

Before we even get to the stacking stage, we have to develop and process all the images in a set. Unlike Lightroom or Camera Raw, ON1 can’t develop and synchronize settings to a set of images at once. You can work on only one image at a time.

So, you work on one image (one of the sky images here), then Copy and Paste its settings to the other images in the set. I show the Paste dialog box here.

This works OK, though I did find some bugs – the masks for some global Effects layers did not copy properly; they copied inverted, as black instead of white masks.

However, Luminosity masks did copy from image to image, which is surprising considering the next point.

The greater limitation is that no Local Adjustments (ones with masks to paint in a correction to a selected area) copy from one image to another … except ones with gradient masks. Why the restriction?

So as wonderful as ON1’s masking tools might be, they aren’t of any use if you want to copy their masked adjustments across several images, or, as shown next, to a large time-lapse set.

While Camera Raw’s and Lightroom’s Local Adjustment pins are more awkward to work with, they do copy across as many images as you like.


Time-Lapse Processing

ON1 Copy & Paste
ON1 does allow developing one image in a set, then copying and pasting its settings to perhaps hundreds of other images in a time-lapse set.

A few Adobe competitors, such as Affinity Photo (as of this writing) simply can’t do this.

By comparison, with the exception of Local Adjustments, ON1 does have good functions for Copying and Pasting Settings. These are essential for processing a set of hundreds of time-lapse frames.

ON1 Export
This is ON1’s Export dialog box, set up here to export the developed raw files into another “intermediate” set of 4K-sized JPGs for movie assembly.

Once all the images are processed – whether it be with ON1 or any other program – the frames have to exported out to an intermediate set of JPGs for assembly into a movie by third-party software. ON1 itself can’t assemble movies, but then again neither can Lightroom (as least not very well), though Photoshop can, through its video editing functions.

For my test set of 220 frames, each with several masked Effects layers, ON1 took 2 hours and 40 minutes to perform the export to 4K JPGs. Photoshop, through its Image Processor utility, took 1 hour and 30 minutes to export the same set, developed similarly and with several local adjustment pins.

ON1 did the job but was slow.

A greater limitation is that, unlike Lightroom, ON1 does not accept any third party plug-ins (it serves as a plug-in for other programs). That means ON1 is not compatible with what I feel are essential programs for advanced time-lapse processing: either Timelapse Workflow (from https://www.timelapseworkflow.com) or the industry-standard LRTimelapse (from https://lrtimelapse.com).

Both programs work with Lightroom to perform incremental adjustments to settings over a set of images, based on the settings of several keyframes.

Lacking the ability to work with these programs means ON1 is not a program for serious and professional time-lapse processing.


Deep-Sky Processing

ON1-Tracked Milky Way
A tracked 2-minute exposure of the Cygnus Milky Way, with a Sony a7III camera at ISO 800 and Venus Optics Laowa 15mm lens at f/2, developed in ON1.

ACR-Tracked Milky Way
The same Milky Way image developed in Adobe Camera Raw. It looks better!

Wide-Angle Milky Way

Now we come to the most demanding task: processing long exposures of the deep-sky, such as wide-angle Milky Way shots and close-ups of nebulas and galaxies taken through telescopes. All require applying generous levels of contrast enhancement.

As the above example shows, try as I might, I could not get my test image of the Milky Way to look as good with ON1 as it did with Adobe Camera Raw. Despite the many ways to increase contrast in ON1 (Contrast, Midtones, Curves, Structure, Haze, Dynamic Contrast and more!), the result still looked flat and with more prominent sky gradients than with ACR.

And remember, with ACR that’s just the start of a processing workflow. You can then take the developed raw file into Photoshop for even more precise work.

With ON1, its effects and filters all you have to work with. Yes, that simplifies the workflow, but its choices are more limited than with Photoshop, despite ON1’s huge number of Presets.

Deep-Sky Close-Ups

ON1 Processed M31
The Andromeda Galaxy, in a stack of six tracked and auto-guided 8-minute exposures with a stock Canon 6D MkII through an 80mm f/6 refractor.

Photoshop Processed M31
The same set of six exposures, stacked and processed with ACR and Photoshop, with multiple masked adjustment layers as at right. The result looks better.

Similarly, taking a popular deep-sky subject, the Andromeda Galaxy, aka M31, and processing the same original images with ON1 and ACR/Photoshop resulted in what I think is a better-looking result with Photoshop.

Of course, it’s possible to change the look of such highly processed images with the application of various Curves and masked adjustment layers. And I’m more expert with Photoshop than with ON1.

But … as with the Cygnus Milky Way image, I just couldn’t get Andromeda looking as good in ON1. It always looked a little flat.

Dynamic Contrast did help snap up the galaxy’s dark lanes, but at the cost of “crunchy” stars, as I show next. A luminosity “star mask” might help protect the stars, but I think the background sky will inevitably suffer from the de-Bayering artifacts.

Star and Background Sky Image Quality

ON1 Processed M31-Close-Up
A 400% close-up of the final Andromeda Galaxy image. It shows haloed stars and a textured and noisy sky background.

Photoshop Processed M31-Close-Up
The same area blown up 400% of the Photoshop version of the Andromeda Galaxy image. Stars and sky look smoother and more natural.

As I showed with the nightscape image, stars in ON1 end up looking too “crunchy,” with dark halos from over sharpening, and also with the blocky de-Bayering artifacts now showing up in the sky.

I feel it is not possible to avoid dark star haloes, as any application of contrast enhancements, so essential for these types of objects, brings them out, even if you back off sharpening at the raw development stage, or apply star masks.

ON1 Processed M31-With & Without
On the left, the image before any processing applied; on the right, after the level of processing needed for such deep-sky images. What starts out looking OK, turns messy.

ON1 is applying too much sharpening “under the hood.” That might “wow” casual daytime photographers into thinking ON1 is making their photos look better, but it is detrimental to deep-sky images. Star haloes are a sign of poor processing.

Noise and Hot Pixels

ON1 With & Without NR and Hot Pixels
With and without noise reduction and hot pixel removal shows stars becoming lost and misshapen with the Remove Hot Pixel option.

ON1’s noise reduction is quite good, and by itself does little harm to image details.

But turn on the Remove Hot Pixel button and stars start to be eaten. Faint stars fade out and brighter stars get distorted into double shapes or have holes in them.

Hot pixel removal is a nice option to have, but for these types of images it does too much harm to be useful. Use LENR or take dark frames, best practices in any case.

Image Alignment and Registration

ON1 Auto-Alignment
The six Andromeda images stacked then “Auto-Aligned” in ON1, with just the top (first) and bottom (last) images turned on here. with the top image switched to Difference blend mode to show any mis-alignment.

Photoshop Auto-Alignment
The same set stacked and “Auto-Aligned” in Photoshop, with the same first and last images turned on and blended with Difference. PS’s alignment is much better, indicated by the image “blacking out” as the two registered frames cancel out.

Before any processing of deep-sky images is possible, it is first necessary to stack and align them, to make up for slight shifts from image to image, usually due to the mount not being perfectly polar aligned. Such shifts can be both translational (left-right, up-down) and rotational (turning about the guide star).

New to ON1 2019 is an Auto-Align Layers function. It worked OK but not nearly as well as Photoshop’s routine. In my test images of M31, ON1 didn’t perform enough rotation.

Once stacked and aligned, and as I showed above, you then have to manually change the opacities of each layer to blend them for noise smoothing.

By comparison, Photoshop has a wonderful Statistics script (under File>Scripts) that will automatically stack, align, then mean or median average the images, and turn the result into a non-destructive smart object, all in one fell swoop. I use it all the time for deep-sky images. There’s no need for separate programs such as Deep-Sky Stacker.

In ON1, however, all that has to be done manually, step-by-step. ON1 does do the job, just not as well.


Wrap-Up

M31 from ON1
The final M31, Andromeda Galaxy image processed with ON1.

ON1 Photo RAW 2019 is a major improvement, primarily in providing a more seamless and less destructive workflow.

Think of it as Lightroom with Layers! 

But it isn’t Photoshop.

Dynamic Contrast
ON1’s useful Dynamic Contrast filter. A little goes a long way.

True to ON1’s heritage as a special effect plug-in, it has some fine Effect filters, such as Dynamic Contrast above, ones I sometimes use from within Photoshop as plug-in smart filters.

Under Sharpen, ON1 does offer a High Pass option, a popular method for sharpening deep-sky objects.

Missing Filters and Adjustments

But for astrophoto use, ON1 is missing a lot of basic but essential filters for pixel-level touch-ups. Here’s a short list:

• Missing are Median, Dust & Scratches, Radial Blur, Shake Reduction, and Smart Sharpen, just to mention a handful of filters I find useful for astrophotography, among the dozens of others Photoshop has, but ON1 does not. But then again, neither does Lightroom, another example of how ON1 is more light Lightroom with layers and not Photoshop.

ON1 Color Adjustment
ON1’s selective Color Adjustment. OK, but where’s the Black and Neutrals?

• While ON1 has many basic adjustments for color and contrast, its version of Photoshop’s Selective Color lacks Neutral or Black sliders, great for making fine changes to color balance in astrophotos.

• While there is a Curves panel, it has no equivalent to Photoshop’s “Targeted Adjustment Tool” for clicking on a region of an image to automatically add an inflection point at the right spot on the curve. This is immensely useful for deep-sky images.

• Also lacking is a basic Levels adjustment. I can live without it, but most astrophotographers would find this a deal-breaker.

• On the other hand, hard-core deep-sky photographers who do most of their processing in specialized programs such as PixInsight, using Photoshop or Lightroom only to perform final touch-ups, might find ON1 perfectly fine. Try it!

Saving and Exporting

ON1 saves its layered images as proprietary .onphoto files and does so automatically. There is no Save command, only a final Export command. As such it is possible to make changes you then decide you don’t like … but too late! The image has already been saved, writing over your earlier good version. Nor can you Save As … a file name of your choice. Annoying!

Opening a layered .onphoto file (even with ON1 itself already open) can take a minute or more for it to render and become editable.

Once you are happy with an image, you can Export the final .onphoto version as a layered .PSD file but the masks ON1 exports to the Photoshop layers may not match the ones you had back in ON1 for opacity. So the exported .PSD file doesn’t look like what you were working on. That’s a bug.

Only exporting a flattened TIFF file gets you a result that matches your ON1 file, but it is now flattened.

Bugs and Cost

I encountered a number of other bugs, ones bad enough to lock up ON1 now and then. I’ve even seen ON1’s own gurus encounter bugs with masking during their live tutorials. These will no doubt get fixed in 2019.x upgrades over the next few months.

But by late 2019 we will no doubt be offered ON1 Photo RAW 2020 for another $80 upgrade fee, over the original $100 to $120 purchase price. True, there’s no subscription, but ON1 still costs a modest annual fee, presuming you want the latest features.

Now, I have absolutely no problem with that, and ON1 2019 is a significant improvement.

However, I found that for astrophotography it still isn’t there yet as a complete replacement for Adobe.

But don’t take my word for it. Download the trial copy and test it for yourself.

— Alan, November 22, 2018 / © 2018 Alan Dyer/AmazingSky.com 

 

Testing the Sony a7III for Astrophotography


Milky Way Rising at Dino Park

I put the new Sony a7III mirrorless camera through its paces for the features and functions we need to shoot the night sky.

Sony’s a7III camera has enjoyed rave reviews since its introduction earlier in 2018. Most tests focus on its superb auto exposure and auto focus capabilities that rival much more costly cameras, including Sony’s own a7rIII and a9. 

For astrophotography, none of those auto functions are of any value. We shoot everything on manual. Indeed, the ease of manually focusing in Live View is a key function. 

In my testing I compared the Sony a7III to two competitive DSLRs, the Canon 6D MkII and Nikon D750.

All three are “entry-level” full-frame cameras, with 24 to 26 megapixels and in a similar price league of $1,500 (Nikon) to 2,000 (Sony). 

I tested a Sony a7III purchased locally. It was not supplied to me by Sony in return for an “influential” blog post.

I did this testing in preparation for the new third edition of my Nightscapes and Time-Lapse eBook, which includes information on Sony mirrorless cameras, as well as many, many other updates and additions!

NOTE: Click or Tap on most images to bring them up full-frame for inspection.

Milky Way Rising at Dino Park
MILKY WAY AT DINOSAUR PARK A stack of 2 x 90-second exposures for the ground, to smooth noise, and at f/2.8 for better depth of field, plus a single 30-second untracked exposure at f/2 for the sky. All with the Laowa 15mm lens and Sony a7III at ISO 3200.


Mirrorless vs. DSLR

Sony a7III with Loawa 15mm
COMPACT CAMERA and LENS
The Sony a7III with the compact but fast Laowa Venus Optics 15mm f/2 lens.

As with Sony’s other popular Alpha 7 and 9 series cameras, the new Alpha 7III is a full-frame mirrorless camera, a class of camera Canon and Nikon have yet to offer, though models are rumoured or promised. 

In the meantime, Sony commands the full-frame mirrorless market.

As its name implies, a mirrorless camera lacks the reflex mirror of a digital single lens reflex camera that, in a DSLR, provides the light path for framing the scene though the optical viewfinder. 

Sony Live View
SONY LIVE VIEW
The Sony a7III’s excellent Live View screen display. You can see the Milky Way!

In a mirrorless, the camera remains in “live view” all the time, with the sensor always feeding a live image to either or both the rear LCD screen and electronic viewfinder (EVF). While you can look through and frame using the EVF as you would with a DSLR, you are looking at an electronic image from the sensor, not an optical image from the lens. 

The advantage of purely electronic viewing is that the image you are previewing matches the image you’ll capture, at least for short exposures. The disadvantage is that full-time live view draws more power, with mirrorless cameras notorious for being battery hungry. 

Other mirrorless advantages include:

  • Compact size and lighter weight, yet offering all the image quality of a full-frame DSLR.
  • The thinner body allows the use of lenses from any manufacturer, albeit requiring the right adapter, an additional expense.
  • Lenses developed natively for mirrorless models can be smaller and lighter. An example is the Laowa 15mm f/2 I used for some of the testing.
  • The design lends itself to video shooting, with many mirrorless cameras offering 4K as standard, while often in DSLRs only high-end models do.
  • More rapid-fire burst modes and quieter shutters are a plus for action and wedding photographers, though they are of limited value for astrophotography.

Points of Comparison

Camera Trio-Sony, Nikon, Canon
CAMERA TRIO
The Sony a7III, Nikon D750, and Canon 6D Mark II. Note the size difference.

In testing the Sony a7III I ignored all the auto functions. Instead, I concentrated on those points I felt of most concern to astrophotographers, such as:

  • Noise levels
  • Effectiveness of Long Exposure Noise Reduction (LENR) 
  • Quality of Raw files, such as sharpness of stars
  • Brightness of Live View for framing and focusing
  • Uniformity of sensor illumination
  • Compatibility for time-lapse imaging
  • Battery life

TL;DR Conclusions

Sony a7III and Meade 70mm
DEEP-SKY TEST
The North America Nebula with the Sony a7III and a Meade 70mm f/5 astrographic refractor, for a single 4-minute exposure at ISO 1600. The reds have been boosted in processing.

Noise
Levels of luminance and chrominance noise were excellent and similar to – but surprisingly not better than – the Nikon D750.

Star Eater
The Star Eater is effectively gone. Stars are not smoothed out in long exposures. 

ISO Invariance 
The Sony exhibited good – though not great – “ISO invariant” performance.

Dark Frames 
Dark frame subtraction using Long Exposure Noise Reduction removed most – but not all – hot pixels from thermal noise. 

Live View Focusing and Framing
Live View was absolutely superb, though the outstanding Bright Monitoring function is as well-hidden as Sony could possibly make it. 

Sensor Illumination Uniformity
The Sony showed some slight edge-of-frame shadowing from the mask in front of the sensor, as well as a weak purple amp glow.

Features 
• The a7III lacks any internal intervalometer or ability to add one via an app. But it is compatible with many external intervalometers and controllers.

• The a7III’s red sensitivity for recording H-Alpha-emitting nebulas was poor. 

• It lacks the “light-frame” buffer offered by full-frame Canons that allows shooting several frames in quick succession even with LENR turned on.

Video Capability 
The a7III offers 4K video and, at 24 frames-per-second, is full-frame. Shutter speeds can be as slow as 1/4-second, allowing real-time aurora shooting at reasonable ISO speeds. 

Battery Life
Shooting typical 400-frame time-lapses used about 40% of the battery capacity, similar to the other DSLRs. 

Overall Recommendations
The Sony a7III is a superb camera for still and time-lapse nightscape shooting, and excellent for real-time aurora videos. It is good, though not great, for long-exposure deep-sky imaging. 

Liberty Schoolhouse with Star Trails
STAR TRAILS and AURORA With the Laowa 15mm lens and Sony a7III, for 155 exposures, all 20 seconds at f/2.8 and at ISO 800, and taken as part of a 360-frame time-lapse.


Noise

The Sony a7III uses a sensor that is “Backside Illuminated,” a feature that promises to improve low-light performance and reduce noise. 

I saw no great benefit from the BSI sensor. Noise at typical astrophoto ISO speeds – 800 to 6400 – were about equal to the four-year-old Nikon D750. 

That was a bit surprising. I expected the new BSI-equipped Sony to better the Nikon by about a stop. It did not. This emphasizes just how good the Nikon D750 is. 

Nevertheless, noise performance of the Sony a7III was still excellent, with both the Sony and Nikon handily outperforming the Canon 6D MkII, with its slightly smaller pixels, by about a stop in noise levels. 

NOTE: I performed all Raw developing with Adobe Camera Raw v10.3. It is possible some of the artifacts I saw are due to ACR not handling the a7III’s .ARW files as well as it should. But to develop all the images from Sony, Nikon, and Canon equally for comparisons, ACR is the best choice. 

1-Sony vs Nikon vs Canon Noise
COMPARING NOISE
The Sony a7III exhibited noise levels similar to the Nikon D750 at high ISOs, with the Sony and Nikon each about a stop better for noise than the Canon 6D MkII.

2A-Sony vs Nikon vs Canon at 3200
NOISE AT ISO 3200
At ISO 3200, a common nightscape ISO speed, all three cameras performed well in this moonlit scene. The Canon shows a darker sky as its images were taken a few minutes later. The Nikon had the Sigma 14mm Art lens; the Canon and Sony used the same Rokinon 14mm SP lens.

2B-Sony vs Nikon vs Canon at 6400
NOISE AT ISO 6400
At ISO 6400, the Canon begins to show excessive noise, about a stop worse than the Nikon and Sony. No luminance noise reduction was applied to these images. All cameras show an equal number of stars recorded.


ISO Invariance

Both the Sony and Nikon use sensor and signal path designs that are “ISO invariant.” As a result, images shot underexposed at slower ISOs, then boosted in exposure later in processing look identical to properly exposed high-ISO images. Well, almost.

The Sony still showed some discoloration artifacts and added noise when boosting images by +4 EV that the Nikon did not. Even with uncompressed Raws, the Sony was not quite as ISO invariant as the Nikon, though the difference shows up only under extreme push-processing of badly underexposed frames. 

Plus, the Sony was far better than the Canon 6D MkII’s “ISO variant” sensor. Canon really needs to improve their sensors to keep in the game. 

3A-Sony vs Nikon vs Canon ISO Invariancy
ISO INVARIANCE COMPARISON
Here I shot all three cameras at ISO 6400 for a correct exposure for the scene, and also at ISO 1600 and ISO 400, for images 2 and 4 stops underexposed respectively. These were then boosted in Adobe Camera Raw by 2 and 4 stops in Exposure Value (EV) to compensate. With ISO invariant sensors the boosted images should look similar to the well-exposed image.

3B-Sony vs Nikon vs Canon ISO Invariancy CU
ISO INVARIANCE CLOSE-UP
A closeup of the scene shows the ISO variant Canon exhibited more noise and magenta discoloration in the +4 EV boosted image. The Nikon looks very clean, but the Sony also shows discoloration, green here, and an increase in noise. These are all uncompressed 14-bit Raw files.

4-Sony vs Nikon ISO Invariancy
SONY vs. NIKON
Comparing just the two ISO-invariant cameras, the Sony and the Nikon, on another night, shows a similar performance difference when boosting underexposed slow-ISO images later in Camera Raw. The Sony begins to show more noise and now a magenta discoloration in the +3 and +4 EV images, similar to, but not as badly as does the ISO-variant Canon 6D MkII.


Compressed vs. Uncompressed 

Sony-Comp-UnCompThe Sony a7III offers a choice of shooting Uncompressed or Compressed Raw files. Uncompressed Raws are 47 Mb in size; Compressed Raws are 24 Mb. 

In well-exposed images, I saw little difference in image quality. 

But the dark shadows in underexposed nightscapes withstood shadow recovery better in the uncompressed files. Compressed files showed more noise and magenta discoloration in the shadows. 

It is not clear if Sony’s compressed Raws are 12-bit vs. 14-bit for uncompressed files. 

Nevertheless, for the demands of nightscape and deep-sky shooting and processing, I suggest shooting Uncompressed Raws. Use Compressed only if you plan to take lots of time-lapse frames and need to conserve memory card space on extended shoots. 

5A-Sony UnCompressed vs Compressed at -1EV
UNCOMPRESSED vs. COMPRESSED
Here I compare any image degradation from using compressed vs. uncompressed Raws, and from employing Long Exposure Noise Reduction. Images are only slightly underexposed and boosted by +1 EV in Camera Raw. Shadow noise is similar in all images, with the ones taken with LENR on showing elimination of colored hot pixels, as they should.

5B-Sony UnCompressed vs Compressed at -4EV
UNCOMPRESSED vs. COMPRESSED at -4EV
The same scene but now underexposed by 4 stops and boosted by +4 EV later shows greater differences. The compressed image shows more noise and discoloration, and the images taken with LENR on, while eliminating hot pixels, show more random luminance noise. Keep in mind, these are vastly underexposed images. 

6-Sony Comp vs Uncomp + DF
UNCOMPRESSED vs. COMPRESSED DEEP-SKY
A real-world deep-sky example shows the same comparison. All images are well-exposed, for tracked and guided 4-minute exposures. The ones taken with LENR on show fewer hot pixels. The compressed images appear identical to the uncompressed files for noise and star content.


Star Eater (Updated March 27, 2021)

Over the last year or so, firmware updates from Sony introduced a much-publicized penchant for Sony Alphas to “eat” stars even in Raw files, apparently due to an internal noise reduction or anti-aliasing routine users could not turn off. Stars were smoothed away along with the noise in exposures longer than 3.2 seconds in some Sony cameras (longer than 30 seconds in others).

I feel that in the a7III the Star Eater has been largely vanquished.

While others beg to differ and claim this camera still eats stars, they offer no evidence of it other than graphs and charts, not A-B photos of actual tracked starfields taken with the Sony vs. another camera thought not to eat stars.

As the images below show, there is a very slight one-pixel-level softening that kicks in at 4 seconds and longer but it did not eat or wipe out stars. Stars are visible to the same limiting magnitude and close double stars are just as well resolved across all exposures. Indeed, at slower ISOs and longer exposures, more stars are visible.

I saw none of the extreme effects reported by others with other Sonys, where masses of faint stars disappeared or turned into multi-colored blotches. It is possible the effect is still present in other Sony Alpha models. I have not tested those.

But in the a7III, I did not see any significant “star eating” in any long exposures even up to the 4 minutes I used for some deep-sky shots. In images taken at the same time with other cameras not accused of star eating, the Sony showed just as many faint stars as the competitors. Stars were visible to just as faint a limiting magnitude, and that’s what counts, NOT graphs and charts, especially when such results are not shown for other cameras.

In short, long exposures showed just as many stars as did short exposures.

This was true whether I was shooting compressed or uncompressed Raws, with or without Long Exposure Noise Reduction. Neither compression nor LENR invoked “star eating.” 

Sony-Star Eater Series @ 200%
STAR EATER SERIES at 200%
This series of tracked images (shown here blown up 200%) goes from 2 seconds to 2 minutes, with decreasing ISO speed to equalize the exposure value across the series. Between 3.2s and 4s a very slight one-pixel-level softening does kick in, reducing noise and very slightly blurring stars. Yet, just as many stars are recorded and are resolved, and at the lower ISOs/longer exposures more stars are visible because faint stars are not lost in the noise.

Sony-Star Eater Series @ 400%
STAR EATER SERIES at 400%
This is the same series as above but now blown up 400% to better reveal the very subtle change in pixel-level sharpness as exposure lengthened from 3.2 to 4 seconds. Noise (most noticeable in the trees) is reduced and stars are very slightly softened. But none are “eaten” or wiped out. And star colors are not affected, though very small stars are sometimes green, an effect seen in other cameras due to de-Bayering artifacts.

7A-Sony vs Canon for Star Eater v1
STAR EATER DEEP-SKY #1
Tracked deep-sky images through a telescope using 4-minute exposures show the Sony a7III recording an equal number of faint stars as the Canon 6D MkII. No luminance noise reduction was applied to these images in processing.

7B-Sony vs Canon for Star Eater v2
STAR EATER DEEP-SKY #2
Another example with 4-minute exposures again demonstrates no problems recording faint stars. The Canon does show more noise than the Sony. No noise reduction was applied in processing. 

7C-Sony vs Nikon for Star Eater
SONY and NIKON COMPARED
For yet more evidence, this is a comparison of the Sony a7III vs. the Nikon D750 in tracked 90-second exposures with 14mm lenses. Again, the Sony records just as many stars as the Nikon.


LENR Dark frames 

Sony-LENRFor elimination of hot pixels from thermal noise I prefer to use Long Exposure Noise Reduction when possible for nightscape and deep-sky images, especially on warm summer nights.

Exceptions are images taken for star trail stacking and for time-lapses, images that must be taken in quick succession, with minimal time gap between frames.

Turning on LENR did eliminate most hot pixels in long exposures, but not all. A few remained. Also, when boosting the exposure a lot in processing, the images taken with LENR on showed more shot and read noise than non-LENR frames. 

The dark frame the camera was taking and subtracting was actually adding some noise, perhaps due to a temperature difference. The cause is not clear. 

Sony advises that when using LENR Raw images are recorded with only 12-bit depth, not 14-bit. This might be a contributing factor. Yet frames taken with LENR on were the same 47 Mb size as normal uncompressed frames.

For those who think this is normal for LENR use, the Nikon D750 shows nothing like this – frames taken with LENR on are free of all hot pixels and do not show more shot or read noise, nor deterioration of shadow detail from lower bit depths.

However, I emphasize that the noise increase from using LENR with the Sony was visible only when severely boosting underexposed images in processing. 

In most shooting situations, I found using LENR provided the overriding positive benefit of reducing hot pixels. It just needs to be better, Sony!

8A-Sony Dark Frames (W and WO LENR)
SONY WITH AND WITHOUT LENR
These are 4-minute exposures of dark frames (i.e. the lens cap on!) taken at room temperature with and without Long Exposure Noise Reduction. In the Sony, LENR did not eliminate all hot pixels nor the magenta amp glow at the left edge. LENR also added a background level of fine noise. These have had exposure and contrast increased to exaggerate the differences.

8B-Nikon Dark Frames (W and WO LENR)
NIKON WITH AND WITHOUT LENR
Dark frames taken with the Nikon D750 under the same circumstances and processed the same show none of the residual hot pixels and added background noise when LENR is employed. Nor is there any amp glow anywhere along the frame edges.

8C-Sony With and Without LENR
SONY REAL-WORLD LENR COMPARISON
A real-world example with the Sony, with a properly exposed nightscape, shows that the ill effects of using LENR don’t show up under normal processing. You do get the benefit of reduced hot pixels in shadows, especially on a warm night like this was. This is a blow-up of the lower corner of the frame, as indicated.


Sensor Illumination 

How evenly an image is illuminated is a common factor when testing lenses. 

But astrophotography, which often requires extreme contrast boosts, reveals non-uniform illumination of the sensor itself, regardless of the optics, originating from hardware elements in front of the sensor casting shadows onto the sensor. 

This is most noticeable – indeed usually only noticeable – when shooting deep-sky targets though telescopes. 

With DSLRs it is the raised mirror which often casts a shadow, produced a dark vignetted band along the bottom of the frame. Its extent varies from camera model to model.

With a mirrorless camera the sensor is not set far back in a mirror box, as it is in a DSLR. As such, I would have expected a more uniformly illuminated sensor. 

Sony a7III - Sensor CU
SENSOR CLOSE-UP showing intruding mask edges.

Instead, I saw a slight shadowing at the top and bottom edges but just at the corners. This is from a thin metal mask in front of the sensor. It intrudes into the light path ever so slightly. It shouldn’t. 

This is an annoying flaw, though applying “flat fields” or ad hoc local adjustments should eliminate this. But that’s a nuisance to do, and should not be necessary with a mirrorless camera.

Worse is that long deep-sky exposures at high ISOs also exhibited a faint purple glow at the left edge, perhaps from heat from nearby electronics, a so-called “amp glow.” Or I’ve read where this is from an internal infrared source near the sensor.

Taking a dark frame with LENR did not eliminate this, and it should, demonstrating again that for whatever reason in the a7III LENR is not as effective as it should be. 

I have not seen such “amp” glows in cameras (at least in the DSLRs I’ve used) for a number of years, so seeing it in the new Sony a7III was another surprise. 

This would be much tougher to eliminate in deep-sky images where the extreme contrast boosts we typically apply to images of nebulas and galaxies will accentuate any odd glows. 

UPDATE: March 27, 2021 — Subsequent firmware updates seem to have eliminated this amp glow. One supplier of filter-modified cameras, Spencer’s Camera, who had refused to modify Sonys because of this glow, now lists many Sony Alphas as suitable for modification. However, the sensor masks and “green stars” (described below) still make the Sony a7III less desirable for deep-sky imaging than other mirrorless cameras I’ve tested.

9A-Sony Full Field
SONY FIELD ILLUMINATION #1
The full field of a deep-sky image taken through an f/5 70mm astrographic refractor shows the minor level of edge darkening at the corners from shadowing of the sensor in the Sony.

New Sony Blog Example
SONY FIELD ILLUMINATION #2 The full field of a deep-sky image taken through an f/6 105mm refractor shows the level of edge darkening at the edges from shadowing of the sensor in the Sony, and the purple “amplifier” glow at the left edge present in all very long exposures.


Red Sensitivity

When shooting deep-sky objects, particularly red nebulas, we like a camera to have a less aggressive infrared cutoff filter, to pick up as much of the deep red Hydrogen-Alpha emission line as possible. 

The Sony showed poor deep-red sensitivity, though not unlike other cameras. It was a little worse than the stock Canon 6D MkII. 

This isn’t a huge detriment, as anyone who really wants to go after deep nebulosity must use a “filter-modified” camera anyway. 

Canon and Nikon both offered factory modified cameras at one time, notably the Canon 60Da and Nikon D810a. Sony doesn’t have an “a” model mirrorless.

To get the most out of the Sony for deep-sky imaging you would have to have it modified by a third-party, though the amp glow described above makes it a poor choice for modification.

10-Canon5D vs 6D vs Sony (Red Nebula)
RED SENSITIVITY COMPARED
Three deep-sky exposures compare cameras for red sensitivity: a filter-modified Canon 5D MkII, a stock Canon 6D MkII, and the stock Sony a7III. As expected the filter-modified camera picks up much more red nebulosity. The Sony doesn’t do quite as well as the Canon 6D MkII.


Live View Focusing and Framing 

Up to now my report on the Sony a7III hasn’t shown as glowing a performance as all the YouTube reviews would have you believe. 

But Live Focus is where the a7III really stands out. I love it!

In Live View it is possible to make the image so bright you can actually see the Milky Way live on screen! Wow! This makes it so easy to frame nightscapes and deep-sky fields.  

Sony-Custom Buttoms
FINDING BRIGHT MONITORING
The excellent Bright Monitoring function is accessible only off the Custom Key menu where it appears as a choice on the Display/Auto Review2 page (below) that can be assigned to a C button.

But this special “Bright Monitoring” mode is as well hidden as Sony could make it. Unless you actually read the full-length 642-page PDF manual (you have to download it), you won’t know about it. Bright Monitoring does not appear in any of the in-camera menus you can scroll through, so you won’t stumble across it.

Instead, you have to go to the Camera Settings 2 page, then select Still Image–Custom Key. In the menu options that appear you can now scroll to one called Bright Monitoring. Surprise! Assign it to one of the hardware Custom C buttons. I put it on C2, making it easy to call up when needed. 

Sony-Bright Monitoring

The other Live View function that works well, but also needs assigning to a C button is the Camera Settings 1 > Focus Magnifier. I put this on C1. It magnifies the Live View by 5.9x or 11.7x, allowing for precise manual focusing on a star. 

Sony-LiveViewDisp

Two other functions are useful for Live View: 

  • Camera Settings 2 > Live View Display > Setting Effect ON. This allows the Live View image to reflect the camera settings in use, better simulating the actual exposure, even without Bright Monitoring on.
  • Camera Settings 1 > Peaking Setting. Turning this ON superimposes a shimmering effect on parts of an image judged in focus. This might be an aid, or an annoyance. Try it. 

In all, the Sony provides superb, if well-hidden, Live View options that make accurately framing and focusing a nightscape or time-lapse scene a joy. 


Great Features for Astrophotography 

Here are some other Sony a7III features I found of value for astrophotogra