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 will include 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 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 June 3, 2018)

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.

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.

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. 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 isn’t a serious flaw, and applying “flat fields” or ad hoc local adjustments would eliminate this.

However, long deep-sky exposures also exhibited a faint purple glow at the left edge, probably from heat from nearby electronics, a so-called “amp glow.” 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 haven’t seen 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 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. 

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.
9B-Sony a7 III Vignetting
SONY FIELD ILLUMINATION #2
Another example taken in twilight to accentuate frame illumination shows the same shadow vignetting and the slight magenta amp glow at the left.

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, such as Hutech, Spencers, or LifePixel though, as of this writing, none list the Sony a7III as a model they can modify.

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 astrophotography, and for operating the camera at night. 

Sony a7III with Tilt Screen
SONY TILTING SCREEN It tilts up and down but does not flip out as with the Canon 6D MkII’s. Still, this is a neck- and back-saving feature for astrophotography.

Tilting LCD Screen 
Like the Nikon D750, the Sony’s screen tilts vertically up and down, great for use when on a telescope, or on any tripod when aimed up at the sky. As photographers age, this becomes a more essential feature!

Sony-CustomKey

Custom Buttons 
The four C buttons can be programmed for oft-used functions, making them easy to access at night. Standard functions such as ISO and Drive Mode are easy to get at on the thumb wheel, unlike the Nikon D750 where I am forever hunting for the ISO or Focus Zoom buttons, or the Canon 6D MkII which successfully hides the Focus Zoom and Playback buttons at night.

Sony-MyMenu

My Menu 
In new models, Sony now offers the option of a final “My Menu” page which you can populate with often-used functions from the other 35 pages of menu commands!

Adaptability to Many Lenses 
Using the right lens adapter (I use one from Metabones), it is possible to use lenses with mounts made for Canon, Nikon, Sigma and others. Plus there are an increasing number of lenses from third parties offered with native Sony E-mounts. This is good news, as astrophotography requires fast, high-quality lenses, and the Sony allows more choices.

Lighter Weight / Smaller Size
The compact a7III body weighs a measured 750 grams, vs. 900 grams each for the Nikon D750 and Canon 6D MkII. The lower weight can be helpful for use on lightweight telescopes, on small motion control devices, and for simply keeping weight and bulk down when traveling. 

Sony a7III - Dual Slots

Dual Card Slots 
Not essential, but having two card slots is very helpful, for backup, for handling overflows from very long time-lapse shoots, or assigning them for stills vs. movies, or Raws vs. JPGs. Only Slot 1 will work with the fastest UHS II cards that are needed for recording the highest quality 4K video.

USB Power 
It is possible to power the camera though the USB port (indeed that’s how you charge the battery, as no separate battery charger is supplied as standard, a deficiency). This might be useful for long shoots, though likely as not that same USB port will be needed for an intervalometer or motion control device. But if the Sony had a built-in intervalometer…!

Sony-DispInfo

Display Options
To reduce battery drain it is possible to turn off the EVF completely – I find I never use it at night – and to turn off the LCD display when shooting, though the latter is an option you have to activate to add to the Display button’s various modes. 

The downside is that when shooting is underway you get no reassuring indication anything is happening, except for a brief LED flash when an image is written to a card.  

Sony-ECurtain

Electronic Front Curtain Shutter
Most DSLRs do not offer this, but the Sony’s option of an electronic front curtain shutter and the additional Silent Shooting mode completely eliminates vibration, useful for some high-magnification shooting through telephotos and telescopes.

11-Sony Shutter Vibration
LUNAR CLOSE-UPS COMPARED
This trio compares closeups of the Moon taken with and without electronic front curtain shutter. All were taken through a 130mm refractor telescope at f/12 using a Barlow lens. The image with e-shutter and in Silent Mode is a tad sharper, but that could be just as much from variations in seeing conditions as from the lower vibration from using the electronic shutter.

What’s Missing for Astrophotography

Intervalometer 
For all the Sony’s 35 pages of Menu functions, a built-in Intervalometer isn’t one of them. While it does have a 1 frame-per-second movie mode in its “Slow-and Quick” functions, that’s not sufficient for night time-lapses, plus S&Q mode only works with HD movies, not 4K.

A built-in intervalometer is not essential, since in time-lapse shooting we often use external controllers anyway. But I find I often do use the Canon and Nikon in-camera intervalometers for simple shoots, and for cold winter aurora shoots. How tough would it be to add it, Sony?

Bulb Timer or Long Exposures
While the Sony has a Bulb setting there is no Bulb Timer as there is with the Canon. The Bulb Timer would allow setting long Bulb exposures of any length in the camera. 

Instead the Sony must be used with an external Intervalometer. I use a $50 Vello unit, and it works very well. It controls the Sony through the camera’s Multi USB port.

In-Camera Image Stacking 
Also missing, and present on most new Canons, are Multiple Exposure modes for in-camera stacking of exposures in a Brighten mode (for star trails) or Averaging mode (for noise smoothing). 

Yes, this can all be done later in processing, but having the camera do the stacking can often be convenient, and great for beginners, as long as they understand what those functions do, or even that they exist!

Time-Lapse Smoothing 
When using its internal intervalometer, the Nikon D750 has an excellent Exposure Smoothing option. This does a fine job smoothing frame-to-frame flickering in time-lapses, something the Canon cannot do. Nor the Sony, as it has no intervalometer at all.

Light Frame Buffer in LENR
This feature is little known and utilized, and only Canon full-frame cameras offer it. Turn on LENR and it is possible to shoot three (with the 6D MkII) or four (with the 6D) Raw images in quick succession even with LENR turned on. The Canon 5D series also has this. 

The dark frame kicks in and locks up the camera only after the series of “light frames” are taken. This is wonderful for taking a set of noise-reduced deep-sky images for later stacking. Nikons don’t have this, not even the D810a, and not Sonys. 

Illuminated Buttons 
The Sony’s buttons are not illuminated. While these might add glows to long exposure images, if they could be designed not to do that (i.e. they turn off during exposures), lit buttons would be very handy at night. 

Limited Touch Screen Functions 
An alternative would be an LCD screen that was touch sensitive. The Sony a7III’s screen is, but only to select an area for auto focus or zooming up an image in playback. The Canon 6D MkII has a fully functional touch screen which can be, quite literally, handy at night.  

Sony a7III with Vello Intervalometer
INTERVALOMETER
For time-lapses, the Sony must be used with an external intervalometer like this Vello unit.

Video Capability 

Here’s another area where the new Sony a7III really shines. 

It offers 4K (or more precisely UltraHD) video recording for videos of 3840 x 2160 pixels. (True 4K is actually 4096 x 2160 pixels.)

With a fast enough UHS-II Class card it can record 4K video up to 30 frames per second and at a bit rate of either 60 or 100 Mbps. 

Sony-MovieSetting

At 24 fps videos are full-frame with no cropping. Hurray! You can take full advantage of wide-angle lenses, great for auroras. At 30 fps, 4K videos are cropped with a 1.2x crop factor.

In Movie Mode ISO speeds go up to ISO 102,400, but are pretty noisy, if unusable at such speeds. 

But when shooting aurora videos I found, to my surprise, I could “drag” the shutter speeds as slow as 1/4-second, fully 4 stops better than the Nikon’s slowest shutter speed of 1/60 second in Full HD, and 3 stops better than the Canon’s slowest movie shutter of 1/30 second. 

Coupled with a fast f/1.4 to f/2 lens, the slow shutter speed allows real-time aurora shooting at “only” ISO 6400 to 12,800, for quite acceptable levels of noise. I am very impressed! 

Real-time video of auroras is not possible with anything like this quality with the Nikon (I’ve used it often), and absolutely not with the Canon. And neither are 4K. 

Is the a7III as good for low-light video as the Sony a7s models, with their larger 8.5-micron pixels? 

I would assume not, but not having an a7s (either Mark I or II) to test I can’t say for sure. But the a7III should do the job for bright auroras, the ones with rapid motion worth recording with video, plus offer 24 megapixels for high-quality stills of all sky subjects. 

I think it’s a great camera for both astrophoto stills and video.

12A-Aurora Video Screen Shot
AURORA VIDEO FRAME
This is a frame grab from a real-time 4K video of a “Steve” aurora.

An example is in a 4K video I shot on May 6, 2018 of an usual aurora known as “STEVE.”

Steve Aurora – May 6, 2018 (4K) from Alan Dyer on Vimeo.


For another example of using the Sony a7III for recording real-time video of the night sky see this example of the Space Station crossing the sky.

Lilac Passages of the ISS (4K) from Alan Dyer on Vimeo.


Sony a7III - Buttons and Dials

Battery Life

I found the a7III would use up about about 40% of the battery capacity in a typical 400-frame time-lapse on mild spring nights, with 30-second exposures. This is with the EVF and rear LCD Display OFF, and the camera in Airplane mode to turn off wireless functions to further conserve battery power. I was using the wired Vello intervalometer. 

This is excellent performance on par with the DSLRs I use. At last, we have a mirrorless camera that not only doesn’t eat stars, it also does not eat batteries! 

One battery can get you through a night of shooting, though performance will inevitably decline in winter, as with all cameras. 

Planets Along the Ecliptic
MILKY WAY and PLANETS With the Sony a7III and Laowa 15mm lens at f/2 for a stack of 4 exposures for the ground to smooth noise and one exposure for the sky, all 30 seconds at ISO 3200.

Lens and Telescope Compatibility 

As versatile as a mirrorless camera is for lens choice, making use of that versatility requires buying the right lens adapter(s). They can cost anywhere from $100 to $400. The lowest cost units just adapt the lens mechanically; the more costly units also transfer lens data and allow auto focusing with varying degrees of compatibility. 

Sony a7III with MetaBones
WITH METABONES CANON ADAPTER
The MetaBones Canon EF-to-Sony E mount adapter transfers lens data and allows auto focus to function.

For use on telescopes, the simple adapters will be sufficient, and necessary as many telescope-to-camera adapters and field flatteners are optimized for the longer lens flange-to-sensor distance of a DSLR. Even if you could get a mirrorless camera to focus without a lens adapter to add the extra spacing, the image quality across the field might be compromised on many telescopes. 

I used the Metabones Canon-to-Sony adapter when attaching the Sony to my telescopes using my existing Canon telescope adapters. Image quality was just fine. 

Sony a7III with Telescope Adapter
ADAPTING TO A TELESCOPE
The MetaBones adapter, as will other brands, adds the correct lens flange to sensor distance for telescope field flatteners to work best.

Time-Lapse Controller Compatibility 

Due to limitations set by Sony, controlling one of their cameras with an external controller can be problematic. 

Devices that trigger only the shutter should be fine. That includes simple intervalometers like the Vello, the Syrp Genie Mini panning unit, and the Dynamic Perception and Rhino sliders, to name devices I use. However, all will need the right camera control cable, available from suppliers like B&H. 

And, as I found, the Sony might need to be placed into Continuous shooting mode to have the shutter fire with every trigger pulse from the motion controller. When used with the Genie Mini (below) the Sony fired at only every other pulse if it was in Single shot mode, an oddity of Sony’s firmware.

Some time-lapse controllers are able to connect to a camera through its USB port and then adjust the ISO and aperture as well, for ramped “holy grail” sunset-to-Milky Way sequences. 

For example, the TimeLapse+ View (see http://www.timelapseplus.com) works great for automated holy grails, but the developer recommends that with most Sonys the minimum allowed interval between shots is longer (8 to 14 seconds) than with Canons and Nikons. See http://docs.view.tl/#camera-specific-notes 

With the Alpine Laboratories Radian2, exposure ramping is not possible with a Sony, only basic shutter triggering. See https://alpinelaboratories.com/pages/radian-2-support-get-started_s 

Sony a7III on Genie Mini
SONY WITH THE SYRP GENIE MINI
The Sony A7III worked well with the Syrp Genie Mini motion controller with the right shutter cable but only when placed in Continuous mode.

Recommendations 

In conclusion, here’s my summary recommendations for the three competitive cameras, rating them from Poor, to Fair, to Good, to Excellent. 

Sony a7III - Angled Front

SONY: I deducted marks from the Sony a7III for deep-sky imaging for its lack of a light frame buffer, poor red sensitivity, odd LENR performance, and amp glow not seen on the other cameras and that dark frames did not eliminate. 

However, I did not consider “star eating” to be a negative factor, as the Sony showed just as many stars and as well-resolved as did the competitors, and what more could you ask for?

I rate the Sony excellent for nightscape imaging and for real-time aurora videos. I list it as just “good” for time-lapse work only because it will not be fully compatible with some motion controllers and rampers. So beware!

Nikon D750 Angled Front

NIKON: I deducted points for real-time video of auroras – the D750 can do them but is pretty noisy with the high ISOs needed. Its red sensitivity is not bad, but its lack of a light frame buffer results a less productive imaging cycle when using LENR on deep-sky shooting. 

I know … people shoot dark frames separately for subtracting later in processing. However, I’ve found these post-shoot darks rarely work well, as the dark frames are not at the same temperature as the light frames, and often add noise or dark holes. 

Canon 6D MkII Angled Front

CANON: The 6D MkII’s lack of an ISO invariant sensor rears its ugly head in underexposed shadows in dark-sky nightscapes. I like its image stacking options, which can help alleviate the noise and artifacts in still images, but aren’t practical for time-lapses. Thus my Good rating for nightscapes but Fair rating for time-lapses. (See my test at https://amazingsky.net/2017/08/09/testing-the-canon-6d-mark-ii-for-nightscapes/)

While the 6D MkII has HD video, it is incapable of any low-light video work.

But … when well exposed, such as in tracked deep-sky images, the 6D MkII performs well. (See my test at https://amazingsky.net/2017/09/07/testing-the-canon-6d-mkii-for-deep-sky/)

And its light-frame buffer is great for minimizing shooting time for a series of deep-sky images with in-camera LENR dark frames, which I find are the best for minimizing thermal noise. Give me a Canon full-frame any day for prime-focus deep-sky shooting. 

It’s just a pity the 6D MkII has only a 3-frame buffer when using LENR. Really Canon? The 2008-vintage 5D MkII had a 5-frame buffer! Your cameras are getting worse for astrophotography while Sony’s are getting better. 

SONY a7III NIKON D750 CANON 6D Mk II
Nightscapes

Excellent 

Excellent  Good
Time-Lapse Good  Excellent  Fair
Real-Time Video (Auroras) Excellent  Fair  Poor
Wide-field Deep Sky Good  Good  Excellent 
Telescopic Deep Sky Good  Good  Excellent 

I trust you’ll find the review of value. Thanks for reading!


ADDENDUM as of JUNE 6, 2018

Since publishing the first results a number of people commented with suggestions for further testing, to check claims that:

  1. The Sony would perform better for noise under dark sky conditions, at high ISOs, rather than the moonlit scene above. OK, let’s try that.
  2. The Sony would perform better in an ISO Invariancy “face-off” if its ISOs were kept above 640, to keep all the images within the Sony’s upper ISO range of its dual-gain sensor design, with two ranges (100 to 400, and 640 on up). Fair enough.
  3. What little “star-eater” effect I saw might be mitigated by shooting on Continuous drive mode or by firing the shutter with an external timer. That’s worth a check, too.

For the additional tests, I shot all images within a 3-hour span on the night of June 5/6, using the Sony a7III, Nikon D750, and Canon 6D MkII, with the respective lenses: the Laowa 15mm lens at f/2, the Sigma 14mm Art at f/2, and the Rokinon 14mm SP at f/2.5.

The cameras were on a Star Adventurer Mini tracker to keep stars pinpoints, though the ground blurred in the longer exposures.


DARK SKY NOISE TEST

I show only the Sony and Nikon compared here, shot at the common range of ISOs used for nightscape shooting, 800 to 12800. All images are equally well exposed. The inset image at right in Photoshop shows the scene, the Milky Way above dark trees in my backyard!

To the eye, the Sony and Nikon look very similar for noise levels, just as in the moonlit scene. Both are very good – indeed, among the best performing cameras for high-ISO noise levels. But the Sony, being four years newer than the Nikon, is not better.

BUT … what the Sony did exhibit was better details in the shadows than the Nikon.

And this was with equal processing and no application of Shadow Recovery. This is where the Sony’s Backside Illuminated sensor with presumably higher quantum efficiency in gathering photons might be providing the advantage. With its good shadow details, you have to apply less shadow recovery in post-processing, which does keep noise down. So points to Sony here.

Sony vs Nikon High ISO Noise (Dark Sky)
SONY vs NIKON HIGH ISO under DARK SKIES
Noise levels appeared visually similar but the Sony showed more shadow details. Excellent!

I did put all the high ISO images through the classic noise reduction program Noise Ninja to measure total Luminance and Chrominance noise, and included the Canon 6D MkII’s images.

The resulting values and graph show the Sony actually measured worse for noise than the Nikon at each high ISO speed, 3200 to 12800, though with both performing much better than the Canon.

The higher noise of the Canon is visually obvious, but I’d say the Sony a7III and Nikon D750 are pretty equal visually for noise, despite the numbers.

Noise Ninja Value Graph
COMPARING NOISE WITH NOISE NINJA

DARK SKY ISO INVARIANCY

Again, here I show only the Sony and Nikon, the two “ISO invariant” cameras. The correct exposure for the scene was 30 seconds at ISO 6400 and f/2. The images shown here were shot at lower ISOs to underexposure the dark scene by 2 to 4 stops or EV. Those underexposed images were then boosted later in processing (in Adobe Camera Raw) by the required Exposure Value to equalize the image brightness.

Contrary to expectations, the Sony did not show any great loss in image quality as it crossed the ISO 640 boundary into its lower ISO range. But the Nikon did show more image artifacts in the “odd-numbered” ISOs of 640 and 500. In this test, the Nikon did not perform as well as the Sony for ISO invariancy. Go figure!

Again, the differences are in images vastly underexposed. And both cameras performed much better than the ISO “variant” Canon in this test.

Sony vs Nikon ISO Invariancy (Dark Sky)
DARK SKY ISO INVARIANCY
Here the Sony a7III performed well and better than the Nikon D750.

STAR EATER REVISITED

I shot images over a wide-range of exposures, from 2 seconds to 2 minutes, but show only the ones covering the 2-second to 4-second range, where the “star-eater” anti-aliasing or noise smoothing applied by Sony kicks in (above 3.2 seconds it seems).

I shot with the Sony a7III on Single shot drive mode, on Continuous Low drive mode (with the camera controlling the shutter speed in both cases), and a set with the Sony on Bulb and the shutter speed set by an external Vello intervalometer.

This is really pixel peeping at 400%. In Single drive mode, stars and noise soften ever so slightly at 4 seconds and higher. In Continuous mode, I think the effect is still there but maybe a little less. In shots on Bulb controlled by the External Timer, maybe the stars at 4 seconds are a little sharper still. But this is a tough call. To me, the star eater effect on the Sony a7III is a non-issue. It may be more serious on other Sony alphas.

Sony Star Eater-Shutter Control Series
STAR EATING vs DRIVE MODE
This series shows star sharpness in images taken in Single and Continuous drive modes, and in Externally Timed exposures.

DE-BAYERING STAR ARTIFACTS

An issue that, to me, has a more serious effect on star quality is the propensity of the Sony, and to some extent the Nikon, to render tiny stars as brightly colored points, unrealistically so. In particular, many stars look green, from the dominance of green-filtered photosites on Bayer-array sensors.

Here I compare all three cameras for this effect in two-minute tracked exposures taken with Long Exposure Noise Reduction (i.e. in-camera dark frame subtraction) off and on.

The Sony shows a lot of green stars with or without LENR. The Nikon seems to discolor stars only when LENR is applied. Why would that be? The Canon is free of any such issue – stars are naturally colored whether LENR dark frames are applied or not.

This is all with Raws developed with Adobe Camera Raw.

When opening the same Raws in other programs (ON1 Photo RAW, Affinity Photo, DxO PhotoLab, and Raw Therapee) the results can be quite different, with stars often rendered with fringes of hot, colored pixels. Or rendered with little or no color at all. Raw Therapee offers a choice of de-Bayering, or “de-mosaic,” routines, and each produces different looking stars, and none look great! Certainly not as good as the Canon rendered with Camera Raw.

What’s going on here is a mystery – it’s a combination of the cameras’ unique Raw file formats and the de-Bayering routines of all the many Raw developers wrestling with the task of rendering stars that occupy only a few pixels. It’s unfair to blame just the hardware or the software.

But this test re-emphasized my thoughts that Canon DSLRs remain the best for long-exposure deep-sky imaging where you can give images as much exposure time as they need, while the ISO invariant Sony and Nikons exceed at nightscape shooting where exposures are often limited and plagued by dark shadows and noise.

Sony vs Nikon vs Canon-LENR Off and On
COLORED STARS COMPARISON
The Sony shows a propensity to render small stars in many vivid and unreal colors. The Nikon can do so after LENR is applied. The Canon is more neutral and natural.

So the pixel-peeping continues!

I hope you found these latest tests of interest.

— Alan, May 31, 2018 / Revised June 6, 2018 / © 2018 Alan Dyer / AmazingSky.com

How to Photograph the Lunar Eclipse


Total Lunar Eclipse, Dec 20, 2010 Partial HDR

The first total lunar eclipse in 2.5 years provides lots of opportunities for some great photos.

On the morning of January 31, before sunrise for North America, the Full Moon passes through the umbral shadow of the Earth, creating the first total eclipse of the Moon since September 27, 2015.

The pre-dawn event provides many photo opportunities. Here’s my summary of tips and techniques for capturing the eclipsed Moon.


But First … What is a Lunar Eclipse?

As the animation (courtesy NASA/Goddard Space Flight Center) shows, an eclipse of the Moon occurs when the Full Moon (and they can happen only when the Moon is exactly full) travels through the shadow of the Earth.

The Moon does so at least two times a year, though often not as a total eclipse, one where the entire disk of the Moon is engulfed by the umbra.

When the Moon is within only the outer penumbral shadow we see very little effect, with a barely perceptible darkening of the Moon, if that. I don’t even list the times below for the start and end of the penumbral phases.

Earth Shadow Edge Colors (Oct 8, 2014)
An HDR stack of images to encompass the range of brightness from the bright portion of the lunar disk (at right here) still just in the penumbral shadow, to the dark portion of the disk at left deep in the umbral shadow. I shot this at the October 8, 2014 total lunar eclipse, from Writing-on-Stone Park in southern Alberta. Taken 7 to 5 minutes before totality began.

It’s only when the Moon begins to enter the central umbral shadow that we see an obvious effect. That’s when the partial eclipse begins, and we see a dark bite appear on the left edge of the Moon. The shadow appears to creep across the Moon to darken more of its disk. While it looks like the shadow is moving across the Moon, it is really the Moon moving into, then out of, the umbral shadow that causes the eclipse.

At this eclipse the partial phases last about an hour before and after totality.

Once the Moon is completely immersed in the umbra, totality begins, and lasts 77 minutes at this eclipse, a generous length. However, in North America, only sites in the western half of the continent get to see all or most of totality.


Where is the Eclipse?

ec2018-Fig01
Courtesy Fred Espenak and Royal Astronomical Society of Canada (Observer’s Handbook)

As the chart above shows, the Pacific area including Hawaii, Australia, and eastern Asia can see the entire eclipse with the Moon high in the evening or midnight sky.

Most of North America (my tips are aimed at North American photographers) can see at least some part of this eclipse.

From the eastern half of the continent the Moon sets at sunrise during either totality (from the central areas of North America), or during the first partial phases (from eastern North America). Those in the east can take advantage of interesting photo opportunities by capturing the partially eclipsed Moon setting in the west in the dawn twilight.

Total Lunar Eclipse (Dec 10, 2011)
The total eclipse of the Moon on December 10, 2011, taken from the the Rothney Astrophysical Observatory, near Priddis, Alberta, and looking west to the Rockies. This is a 2 second exposure at ISO 800 with the Canon 5DMkII and Canon 200mm lens at f/4. This was taken toward the end of totality at 7:48 a.m. local time.

However, the most dramatic images of a deep red Moon in the western sky, such as above, will be possible only from the west. And even then, the further north and west you live, the better your view.

Even from the southwestern United States the Moon sets just after the end of totality, requiring a site with a low and clear horizon to the west in order to see the whole event.

I live in Alberta, Canada, and the diagrams I provide here are for my area, where the Moon sets during the final partial phase. I offer them as examples of the kinds of planning you can do to ensure great photos. But exactly where the Moon will be during totality, and where and when it will set on your horizon, will depend on your location.

To plan your local shoot, I suggest using planetarium software such as Stellarium or Starry Night (the software I used to prepare the charts below), and photo planning apps such as The Photographer’s Ephemeris or PhotoPills

The latter two apps present the sightlines toward the Moon overlaid on a map of your location, to help you plan where to be to shoot the eclipsed Moon setting behind a suitable foreground.


When is the Eclipse?

While where the Moon is in your sky depends on your site, the various eclipse events happen at the same time for everyone, with differences in hour due only to the time zone you are in.

Here are the times for the start and end of the partial and total phases.

Note that all times are A.M., in the early morning, before sunrise, on January 31. Go out at 6 P.M. on the evening of January 31 and you’ll be 12 hours too late. You missed it!

Eclipse Times Table

All times are A.M. on January 31. “—“ means the event is not visible; the Moon has set.

The time of moonset at your site will vary with your location. Use planning apps to calculate your local moonset time.


Picking a Site

No matter where you are in North America you want a site with a good view to the west and northwest, preferably with a clear view of a relatively unobstructed but photogenic horizon.

While having an eclipse occur at dawn (or at dusk) does limit the amount of eclipse we can see, it has the benefit of providing many more photo opportunities of the eclipsed Moon above a scenic landscape or foreground element.

Eclipse Moonrise at Writing-on-Stone
The Full Moon rises in partial eclipse over the sandstone formations of Writing-on-Stone Provincial Park in southern Alberta, on the evening of September 27, 2015. Shot with the 200mm lens and 1.4x extender, on the Canon 5DMkII.

From eastern North America you will have to be content with images of the partially eclipsed Moon setting, similar to the image above of a rising partially-eclipsed Moon.

From the centre of the continent, where the Moon sets during totality, the dim, reddened Moon is likely to disappear into the brightening sky. Remember, when the Moon is full it sets just as the Sun rises. So shots of a red Moon right on the horizon aren’t likely to be possible. The Moon will be too dim and the sky too bright.

From sites in the west, the Moon will set either just at the end of totality or shortly afterwards, making the Moon brighter and more obvious in the sunrise sky, as the foreground in the west lights up with red light from the Sun rising in the east.

It is that same red sunlight filtered by our atmosphere that continues on into our planet’s shadow and lights the Moon red during totality.


Picking a Technique

Lunar eclipses lend themselves to a wide range of techniques, from a simple camera on a tripod, to a telescope on a tracking mount following the sky.

What you use depends not only on the gear you have on hand, but also on your site. It might not be practical to set up loads of gear at a scenic site you have to trek into — especially when you have to set up in the wee hours of a cold winter morning.

You could set up earlier that night on January 30, but only if your site is safe enough to leave the gear unattended while you sleep.

Keep it simple!


Option 1: Simple Camera-on-Tripod

Eclipsed Moon over Writing on Stone
The Moon in totality in the deep twilight on September 27, 2015, with a 35mm lens on a full-frame camera. This is one frame from a time-lapse sequence. A 5-second exposure at f/2.8 and at ISO 800.

The easiest method is to take single shots with a moderate wide-angle or normal lens with the camera on a fixed tripod. No fancy trackers are needed here.

If the sky is bright with twilight, you might be able to meter the scene and use Auto exposure.

Jan 31 Eclipse-50mm Mid-Totality (Courtesy Starry Night™/Simulation Curriculum)
Composing a single shot during mid-totality from southern Alberta, framed to include Castor and Pollux in Gemini.

But earlier in the night, with the Moon in a darker sky, as I show above, use Manual exposure and try settings of 1 to 10 seconds at f/2.8 to f/4 at ISO 400 to 1600. That’s a wide range, to be sure, but it will vary a lot depending on when you shoot and where you are, factors that will affect how bright the sky is at your site. Just shoot, check, and adjust.


Option 2: Advanced Camera-on-Tripod

A more advanced method is to compose the scene so the lens frames the entire path of the Moon from the start of the partial eclipse until moonset.

Jan 31 Eclipse-35mm Lens Sequence
Framing a time-lapse sequence for southern Alberta. (Courtesy Starry Night™/Simulation Curriculum)

As shown above, that will take at least a 35mm lens on a full frame camera, or 20mm lens on a cropped frame camera.

Take exposures every 15 to 30 seconds if you want to turn the set into a time-lapse movie. But a still-image composite with the lunar disks well separated will need shots only every 5 to 10 minutes.

Such a composite takes good planning and proper exposures to pull off, but will be true to the scene, with the lunar disk and its motion shown to the correct scale as it was in the sky. That’s in stark contrast to the flurry of ugly “faked” composites that will appear on the web by the end of February 1, ones with huge telephoto Moons pasted willy-nilly onto a wide-angle sky. Don’t do it!

Exposures for any lunar eclipse are tricky, whether you are shooting closeups or wide-angles, because the Moon and sky change so much in brightness.

For wide-angle composites, you can expose just for the bright lunar disk and let the sky go dark. Exposures for just the Moon will range from very short (about 1/500th second at ISO 100) for the partials, to 1 to 2 seconds at ISO 400 for the totals, then shorter again (1/15 to 1/2 second at ISO 400) for the end shots in twilight when the Moon and sky may be similar in brightness. That’ll take constant monitoring and adjusting throughout the shoot.

As I did below, you’d then composite and layer the well-exposed disks into another background image exposed longer for the sky, likely shot in twilight. To maintain the correct relative locations of the lunar disks and foreground, the camera cannot move.

That technique works best if it’s just a still image you are after, such as below.

Lunar Eclipse Sequence from Monument Valley
The total lunar eclipse of April 4, 2015 taken from near Tear Drop Arch, in Monument Valley, Utah. I shot the totality images at 6:01 a.m. MDT, during mid-totality during the very short 4 minutes of totality. The mid-totality image is a composite of 2 exposures: 30 seconds at f/2.8 and ISO 1600 for the sky and landscape, with the sky brightening blue from dawn twilight, and 1.5 seconds at f/5.6 and ISO 400 for the disk of the Moon itself. Also, layered in are 26 short exposures for the partial phases, most being 1/125th sec at f/8 and ISO 400, with ones closer to totality being longer, of varying durations. All are with a 24mm lens and Canon 6D on a static tripod, with the camera not moved through the entire sequence. The short duration of totality at this eclipse lent itself to a sequence with one total phase image flanked by partial phases.

The above image is a composite of the April 4, 2015 total lunar eclipse from Monument Valley, Utah. That eclipse occurred under similar circumstances as this month’s eclipse, with the eclipse underway as the Moon set in the west at sunrise.

Lunar Eclipse From Beginning to End, To True Scale
A multiple-exposure composite of the total lunar eclipse of Sunday, September 27, 2015, as shot from Writing-on-Stone Provincial Park, Alberta, Canada. NOTE: The size of the Moon and its path across the sky are accurate here, because all the images for this composite were taken with the same lens using a camera that did not move during the shoot.

By comparison, the composite here is made of a few selected frames out of hundreds I took at 15-second intervals, and with each frame exposed for the sky, for use in a time-lapse movie. In this case, the Moon became overexposed at the end as it emerged from the umbra.

Indeed, if it’s a time-lapse movie you want (see the video linked to below), then each frame will have to be exposed well enough to show the sky and landscape.

While this method will overexpose the partially-eclipsed Moon, the Moon will darken and become better exposed throughout totality when the same long exposure for the reddened Moon might also work for the sky, to pick up stars. Exposures will have to shorten again as the sky brightens with twilight.

Again, constant baby-sitting and adjusting the camera will be needed. So if it’s cold where you are prepare for a frigid multi-hour shoot. I doubt you’ll be able to leave the camera on Auto exposure to run on its own, not until at least bright twilight begins.


Option 3: Telephoto Close-Ups

Jan 31 Eclipse-Telescope
Size of the Moon with a 600mm telephoto on a full-frame and cropped-frame camera. (Courtesy Starry Night™/Simulation Curriculum)

The Moon is surprisingly small (only 1/2-degree across) and needs a lot of focal length to do it justice.

For an “in-your-face” close-up of the eclipse you’ll need a 300mm to 800mm (!) lens. Unfortunately, the Moon and sky are moving and any exposures over 1 to 2 seconds (required during totality) will blur the Moon badly if its disk is large on the frame.

If you don’t have a tracking mount, one solution is to keep the Moon’s disk small (using no more than a fast f/2.8 200mm lens) and exposures short by using a high ISO speed.

Total Lunar Eclipse (Dec 10, 2011)
The eclipse of December 10, 2011, with the Moon setting in deep partial eclipse at sunrise.

Or plan to shoot with a telephoto only when the Moon is low in the sky, as I did above, when you can include the horizon which you would want to be sharp anyway. Framing the Moon and horizon won’t need a super telephoto.

The sky will then also be brighter and require short exposures that don’t need to be tracked. However, how bright and obvious the Moon will be will again depend on your location. This may or may not be a practical option, certainly not if the Moon is setting during mid-totality where you are.

Option 4: Tracked Telescopic Close-Ups 

Jan 31 Eclipse-Telephoto Lenses
Framing the eclipsed Moon and the Beehive star cluster (Messier 44). (Courtesy Starry Night™/Simulation Curriculum)

If you have a mount that can be polar aligned to track the sky, then more options are open to you.

You can use a telescope mount or one of the compact and portable trackers, such as the Sky-Watcher Star Adventurer or iOptron Sky Tracker units. While these latter units work great, you are best to keep the payload weight down and your lens size under 300mm.

That’s just fine for this eclipse, as you really don’t need a frame-filling Moon. The reason is that the Moon will appear about 4 degrees away from the bright star cluster called the Beehive, or Messier 44, in Cancer. As shown above, a 200mm to 300mm lens will frame this unique pairing well.

Even so, exposures to show the cluster properly might have to be long enough that the Moon overexposes, even at mid-totality. If so, take different exposures for the Moon and stars and composite them later, as I did below.

Total Lunar Eclipse, Dec 20, 2010 Total HDR
A High Dynamic Range composite of 7 exposures of the Dec 20/21, 2010 total lunar eclipse, from 1/2 second to 30 seconds, to show the more normally exposed eclipsed Moon with the star cluster M35 at left in Gemini, to show the scene more like it appeared in binoculars. Each photo taken with a 77mm aperture Borg apo refractor at f/4.2 (300mm focal length) and Canon 5D MkII camera at ISO 1600.

If you do want to shoot with more focal length, a monster telephoto lens will work, but a small telescope such as an 80mm aperture f/6 to f/7 refractor will provide enough focal length and image size at much lower cost. But either way, the lens or telescope should be mounted on a solid equatorial telescope mount, and polar aligned to track the sky.

For the sharpest lunar disks, use the Lunar tracking rate.

Exposures will vary from as short as 1/500th second at ISO 100 to 200 for the barely eclipsed Moon, to 4 to 16 seconds at f/6 to f/8 and at ISO 400 to 1600 for the Moon at mid-totality.

Total Lunar Eclipse, Dec 20, 2010 Partial HDR
Total eclipse of the Moon, December 20/21, 2010, taken with a 130mm AP apo refractor at f/6 and Canon 7D at ISO 400. An HDR composite of 9 images from 1/125 second to 2 seconds, composited in Photoshop.Taken at about 12:21 a.m. MST on Dec 21, about 20 minutes before totality began, during the partial phase.

As I did above, during the deep partial phases shoot both long exposures for the red umbra and short exposures for the bright part of the Moon not yet in the umbra. Merge those later with High Dynamic Range (HDR) techniques and software, or with luminosity masks.

Even if you’re not sure how to do this now, shoot all the required exposures anyway so you’ll have them when your processing skills improve.

Option 5: Time-Lapse Close-Ups 

Total Lunar Eclipse (December 20/21, 2010)
Total eclipse of the Moon, December 20/21, 2010, taken from home with 130mm AP apo refractor at f/6 and Canon 7D at ISO 400 for 4 seconds, single exposure, shortly after totality began.

With a tracking telescope you could fire shots every 30 seconds or so, and then assemble them into a time-lapse movie.

But as with wide-angle time-lapses, that will take constant attention to gradually and smoothly shift exposures, ideally by 1/3rd-stop increments every few shots during the partial and total phases.

If you track at the lunar rate, as I did in the still image below and in the music video linked to at bottom, the Moon will stay centred while it drifts though the stars.

Total Lunar Eclipse-August 28, 2007
Taken with 90mm Stowaway AP Refractor, with Borg .85x compressor/flattener for f/5.6. With Canon 20Da camera at ISO 400 for a 13 second exposure, on a Skywatcher HEQ5 mount tracking at Lunar rate. Exposure was long to bring out star background.

Track at the sidereal rate and the stars will stay more or less fixed while the Moon drifts through the frame from right to left (west to east). But that takes even more careful planning to position the Moon correctly at the start of the sequence so it remains “in frame” for the duration of the eclipse and ends up where you want at the end, which will occur with the Moon low in a bright sky.

Again, planetarium software such as Starry Night, which can be set to display a camera frame, is essential to plan the shoot.

Either way, do take care to accurately polar align your mount, or you’ll be confronted with the monumental task of having to manually align hundreds of images later. Trust me, I know!

Watching the Lunar Eclipse
Me enjoying the September 27, 2015 total lunar eclipse while various cameras snapped away, but still requiring constant attention and adjustments.

I would consider the telescopic time-lapse method the most challenging of techniques.

Considering the hour of the night and the likely cold temperatures, your best plan might be to keep it simple. It’s what I plan to do. I’ll be happy to get a few good wide-angle still images, and perhaps a tracked telephoto close-up of the Moon and Beehive as a bonus.

While there is another total lunar eclipse (TLE) in six months on July 27/28, it is not visible at all from North America.

Our next TLE occurs 12 Full Moons, or one lunar year from now, on the night of January 20/21, 2019, when all of North America gets to watch totality at a more reasonable hour, though perhaps not at a more reasonable temperature.

I leave you with a music video of the last TLE, on September 27, 2015 that incorporates still and time-lapse sequences shot using all of the above methods.

Enjoy!

Selfie Success Shot at Lunar Eclipse
Success! A post-totality trophy shot.

Good luck and clear skies on eclipse morning!

— Alan, January 6, 2018 / © 2018 Alan Dyer / amazingsky.com

 

Top 10 Tips for Practicing for the Eclipse


Total Eclipse from Chile

I present suggestions for how to ensure everything under your control will go well on eclipse day. The secret is: Practice, Practice, Practice!

The techniques I suggest practicing are outlined in my previous blog, Ten Tips for the Solar Eclipse. It’s prerequisite reading.

However, while you can read all about how to shoot the eclipse, nothing beats actually shooting to ensure success. But how do you do that, when there’s only one eclipse?

Here are my “Top 10” suggestions:

Total Eclipse of the Sun from the Atlantic (Nov 3, 2013)
Total eclipse of the Sun, November 3, 2013 as seen from the middle of the Atlantic Ocean, from the Star Flyer sailing ship. I took this with a Canon 5D MkII and 16-35mm lens at 19mm for 1/40s at f/2.8 and ISO 800 on a heavily rolling ship.

Wide-Angle Shots – Shoot a Twilight Scene

The simplest way to shoot the eclipse is to employ a camera with a wide lens running on auto exposure to capture the changing sky colors and scene brightness.

  1. Auto Exposure Check in Twilight

    If you intend to shoot wide-angle shots of the eclipse sky and scene below, with anything from a mobile phone to a DSLR, practice shooting a time-lapse sequence or a movie under twilight lighting. Does your camera expose properly when set to Auto Exposure? If you are using a phone camera, does it have any issues focusing on the sky? How big a file does a movie create? 

 


PRACTICE2-Voyager Alt-Az Mount

With Telephotos and Telescopes – Shoot the Filtered Sun

The toughest techniques involve using long lenses and telescopes to frame the eclipsed Sun up close. They need lots of practice. 

  1. Framing and Focusing

    You’ll need to have your safe and approved solar filter purchased (don’t wait!) that you intend to use over your lens or telescope. With the filter in place, simply practice aiming your lens or telescope at the Sun at midday. It’s not as easy as you think! Then practice using Live View to manually focus on the edge of the Sun or on a sunspot. Can you get consistently sharp images?

 


Partial Solar Eclipse in Cloud #1 (Oct 23, 2014)
The partial eclipse of the Sun, October 23, 2014, shot through thin cloud, but that makes for a more interesting photo than one in a clear sky. Despite the cloud, this was still shot through a Mylar filter, on the front of telescope with 450mm focal length, using the Canon 60Da for 1/25 sec exposure at ISO 100.
  1. Exposure Times

Exposures of the filtered Sun will be the same as during the partial phases, barring cloud or haze, as above, that can lengthen exposure times. Otherwise, only during the thin crescent phases will shutter speeds need to be 2 to 3 stops (or EV steps) longer than for a normal Sun.

 


PRACTICE4-Kendrick and Seymour Filters
Solar filters that clamp around the front of lenses are easier to remove than ones that screw onto lenses. They will bind and get stuck!
  1. Filter Removal

With the camera aimed away from the Sun (very important!), perhaps at a distant landscape feature, practice removing the filter quickly. Can you do it without jarring the camera and bumping it off target? Perhaps try this on the Moon at night as well, as it’s important to also test this with the camera and tripod aimed up high.

 


PRACTICE5-Nikon Screens on 80mm
Articulated LCD screens are a great aid for framing and viewing the eclipse in Live View when the camera is aimed up high, as it will be!
  1. Ease of Use

With the Sun up high at midday (as it will be during the eclipse from most sites), check that you can still look through, focus, and operate the camera easily. Can you read screens in the bright daylight? What about once it gets darker, as in twilight, which is how dark it will get during totality.

 


PRACTICE6-Sun Motion Composite
The east-to-west motion of the sky will carry the Sun its own diameter across the frame during totality, making consistent framing an issue with very long lenses and telescopes.
  1. Sun Motion

If you are using an untracked tripod, check how much the Sun moves across your camera frame during several minutes. For videos you might make use of that motion. For still shots, you’ll want to ensure the Sun doesn’t move too far off center.

 


PRACTICE7-HEQ5 with 80mm Mount N
An equatorial mount like this is great but needs to be at least roughly polar aligned to be useful.
  1. Aligning Tracking Mounts

If you plan to use a motorized equatorial mount capable of tracking the sky, “Plan A” might be to set it up the night before so it can be precisely polar aligned. But the reality is that you might need to move on eclipse morning. To prepare for that prospect, practice roughly polar aligning your mount during the day to see how accurate its tracking is over several minutes. Do that by leveling the mount, setting it to your site’s latitude, and aiming the polar axis as close as you can to due and true north. You don’t need precise polar alignment to gain the benefits of a tracking mount – it keeps the Sun centered – for the few minutes of totality.

 


The March Mini-Moon
The Full Moon is the same brightness as the Sun’s inner corona.

Telephotos and Telescopes – Shoot Full Moon Closeups 

  1. Exposure Check

Shoot the Full Moon around July 8 or August 7. If you intend to use Auto Exposure during totality, check how well it works on the Full Moon. It’s the same brightness as the inner corona of the Sun, though the Moon occupies a larger portion of the frame and covers more metering sensor points. This is another chance to check your focusing skill.

 


Impending Occultation of Beta Capricorni
The crescent Moon has a huge range in brightness and serves as a good test object. Remember, the Moon is the same size as the Sun. That’s why we get eclipses!

Telescopes and Telescopes – Shoot Crescent Moon Closeups

  1. Exposure Check

Shoot the waxing crescent moon in the evening sky during the last week of June and again in the last week of July. Again, test Auto Exposure with your camera in still or movie mode (if you intend to shoot video) to see how well the camera behaves on a subject with a large range in brightness. Or step through a range of exposures manually, from short for the bright sunlit crescent, to long for the dark portion of the Moon lit by Earthshine. It’s important to run through your range of settings quickly, just as you would during the two minutes of totality. But not too quickly, as you might introduce vibration. So …

 


PRACTICE10-2006 Libya-Short
Good focus matters for recording the fine prominences and sharp edge of the Moon.
  1. Sharpness Check

In the resulting images, check for blurring from vibration (from you handling the camera), from wind, and from the sky’s east-to-west motion moving the Moon across the frame, during typical exposures of 1 second or less.

 


By practicing, you’ll be much better prepared for the surprises that eclipse day inevitably bring. Always have a less ambitious “Plan B” for shooting the eclipse simply and quickly should a last-minute move be needed.

However, may I recommend …

How to Photograph the Solar Eclipse
My 295-page ebook on photographing the August 21 total eclipse of the Sun is now available. See http://www.amazingsky.com/eclipsebook.html It covers all techniques, for both stills, time-lapses, and video, from basic to advanced, plus a chapter on image processing. And a chapter on What Can Go Wrong?! The web page has all the details on content, and links to order the book from Apple iBooks Store (for the best image quality and navigation) or as a PDF for all other devices and platforms.

For much more detailed advice on shooting options and techniques, and for step-by-step tutorials on processing eclipse images, see my 295-page eBook on the subject, available as an iBook for Apple devices and as a PDF for all computers and tablets.

Check it out at my website page

Thanks and clear skies on August 21!

— Alan, June 24, 2017 / © 2017 Alan Dyer / amazingsky.com

 

Ten Tips for the Solar Eclipse


Total Eclipse from Libya 2006I present my Top 10 Tips for photographing the August 21 total eclipse of the Sun.

If the August total eclipse will be your first, then you could heed the advice of many and simply follow “Tip #0:” Just don’t photograph it! Look up and around to take in the spectacle. Even then, you will not see it all.

However, you might see less if you are operating a camera.

But I know you want pictures! To help you be successful, here are my tips for taking great photos without sacrificing seeing the eclipse.


TIP1-iPhone on Siriu Tripod
An iPhone in a tripod bracket and on a small tabletop tripod.

TIP #1: Keep It Simple

During the brief minutes of totality, the easiest way to record the scene is to simply hold your phone camera up to the sky and shoot. Zoom in if you wish, but a wide shot may capture more of the twilight effects and sky colors, which are as much a part of the experience as seeing the Sun’s gossamer corona around the dark disk of the Moon.

Better yet, use an adapter to clamp your phone to a tripod. Frame the scene as best you can (you might not be able to include both the ground and Sun) and shoot a time-lapse, or better yet, a video.

Start it 2 or 3 minutes before totality (if you can remember in the excitement!) and let the camera’s auto exposure take care of the rest. It’ll work fine.

That way you’ll also record the audio of your excited voices. The audio may serve as a better souvenir than the photos. Lots of people will have photos, but nobody else will record your reactions!

Just make sure your phone has enough free storage space to save several minutes of HD video or, if your camera has that feature, 4K video.


TIP2-2006 Libya Wide-Angle
A wide shot of the 2006 eclipse in Libya with a high altitude Sun. 10mm lens on a cropped-frame Canon 20Da camera.

TIP #2: Shoot Wide With a DSLR

For better image quality, step up to this hands-off technique.

Use a tripod-mounted camera that accepts interchangeable lenses (a digital single lens reflex or a mirrorless camera) and use a lens wide enough to take in the ground below and Sun above.

Depending on where you are and the sensor size in your camera, that’ll likely mean a 10mm to 24mm lens.

By going wide you won’t record details in the corona of the Sun or its fiery red prominences. But you can record the changing sky colors and perhaps the dark shadow of the Moon sweeping from right to left (west to east) across the sky. You can also include you and your eclipse group silhouetted in the foreground. Remember, no one else will record you at the eclipse.


TIP3-2012 Eclipse Movie Clip
A sequence of shots of the 2012 eclipse from Australia, with a wide 15mm lens and camera on Auto Exposure showing the change of sky color.
Total Eclipse of the Sun, Mid-Eclipse (Wide-Angle)
The total eclipse of the Sun, November 14, 2012, from a site near Lakeland Downs, Queensland, Australia. Shot with the Canon 5D Mark II and 15mm lens for a wide-angle view showing the Moon’s conical shadow darkening the sky and the twilight glow on the horizon. Taken near mid-eclipse.

TIP #3: Shoot on Auto Exposure

For wide shots, there’s no need to attend to the camera during the eclipse. Set the camera on Auto Exposure – Aperture Priority (Av), the camera ISO between 100 to 400, and your lens aperture to f/2.8 (fast) to f/5.6 (slow).

Use a higher ISO if you are using a slower lens such as a kit zoom. But shoot at ISO 100 and at f/2.8 if you have a wide lens that fast.

In Av mode the camera will decide what shutter speed to use as the lighting changes. I’ve used this technique at many eclipses and it works great.


TIP4-Pixel Intervalometer CU
An accessory intervalometer set for an interval of 1 second.

TIP #4: Let the Camera Do the Shooting

To make this wide-angle technique truly hands-off use an intervalometer (either built into your camera or a separate hardware unit) to fire the shutter automatically.

Once again, start the sequence going 3 to 5 minutes before totality, with the intervalometer set to fire the shutter once every second. Don’t shoot at longer intervals, or you’ll miss too much. Shutter speeds won’t likely exceed one second.

Again, be sure your camera’s memory card has enough free space for several hundred images. And don’t worry about a solar filter on your lens. It’ll be fine for the several minutes you’ll have it aimed up.

Out of the many images you’ll get, pick the best ones, or turn the entire set into a time-lapse movie.


TIP5-Manual Focus Switches Nikon
A Nikon DSLR and lens set to Manual Focus.

TIP #5: Shoot on Manual Focus

Use Auto Exposure and an intervalometer. But … don’t use Auto Focus.

Switch your lens to Manual Focus (MF) and focus on a distant scene element using Live View.

Or use Auto Focus to first focus on something in the distance, then switch to Manual and don’t touch focus after that. If you leave your lens on Auto Focus the shutter might not fire if the camera decides it can’t focus on the blank sky.


TIP6-Lightoom Wide-Angle
A comparison of a Raw image as it came from the camera (left) and after developing in Lightroom (right).

TIP #6: Shoot Raw

For demanding subjects like a solar eclipse always shoot your images in the Raw file format. Look in your camera’s menus under Image Quality.

Shoot JPGs, too, if you like, but only Raw files record the widest range of colors and brightness levels the camera sensor is capable of detecting.

Later in processing you can extract amazing details from Raw files, both in the dark shadows of the foreground, and in the bright highlights of the distant twilight glows and corona around the Sun. Software to do so came with your camera. Put it to use.


TIP7-200mm Lens on Tripod
A 200mm telephoto and 1.4x Extender, with the camera on a sturdy and finely adjustable tripod head.

TIP #7: OK, Use a Telephoto Lens! But …

If you really want to shoot close-ups, great! But don’t go crazy with focal length. Yes, using a mere 135mm or 200mm lens will yield a rather small image of the eclipsed Sun. But you don’t need a monster 600mm lens or a telescope, which typically have focal lengths starting at 600mm. With long focal lengths come headaches like:

 Keeping the Sun centered. The Earth is turning! During the eclipse that motion will carry the Sun (and Moon) its own diameter across your frame from east to west during the roughly two minutes of totality. While a motorized tracking mount can compensate for this motion, they take more work to set up properly, and must be powered. And, if you are flying to the eclipse, they will be much more challenging to pack. I’m trying to keep things simple!

 Blurring from vibration. This can be an issue with any lens, but the longer your lens, the more your chances of getting fuzzy images because of camera shake, especially if you are touching the camera to alter settings.

An ideal focal length is 300mm to 500mm. But …

When using any telephoto lens, always use a sturdy tripod with a head that is easy to adjust for precise aiming, and that can aim up high without any mechanical issues. The Sun will be halfway, or more, up the sky, not a position some tripod heads can reach.


Total Solar Eclipse (2012 from Australia)
A re-processed version of a still frame of the total solar eclipse of November 14, 2012 taken from our site at Lakeland Downs, Queensland, Australia. This is a still frame shot during the shooting of an HD video of the eclipse, using the cropped-frame Canon 60Da and Astro-Physics Traveler 4-inch apo refractor telescope at f/5.8 (580mm focal length). The image is 1/60th second at ISO 100. This is a full-sized still not a frame grab taken from the movie.
TIP8-Eclipse Movie Clip 2012
A sequence from a movie showing the camera adjusting the exposure automatically when going from a filtered view (left) to an unfiltered view of the diamond ring (right).

TIP #8: Use Auto Exposure, or … Shoot a Movie

During totality with your telephoto, you could manually step through a rehearsed set of exposures, from very short shutter speeds (as short as 1/4000 second) for the diamond rings at either end of totality, to as long as one or two seconds at mid-totality for the greatest extent of the corona’s outermost streamers.

But that takes a lot of time and attention away from looking. Yes, there are software programs for automating a camera, or techniques for auto bracketing. But if this is your first eclipse an easier option is to simply use Auto Exposure/Aperture Priority and let the camera set the shutter speed. Again, you could use an intervalometer to fire the shutter so you can just watch.

Don’t use high ISO speeds. A low ISO of 100 to 400 is all you need and will produce less noise. The eclipsed Sun is still bright. You don’t need ISO 800 to 3200.

Even on Auto Exposure, you’ll get good shots, just not of the whole range of phenomena an eclipsed Sun displays.

Or, once again and better yet – put your camera into video mode and shoot an HD or 4K movie. Auto Exposure will work just fine, allowing you to start the camera then forget it.

Place the Sun a solar diameter or two to the left of the frame and let the sky’s motion drift it across the frame for added effect. Start the sequence running a minute or two before totality with your solar filter on. Then just let the camera run … except …


TIP9-66mm on Stellarvue
A small refractor telescope with a solar filter over the front aperture. That filter has to be removed for totality.

TIP #9: Remember to Remove the Filter!

You will need a safe solar filter over your lens or telescope to shoot the partial phases of the eclipse, and to frame and focus the Sun. This cannot be a photo neutral density or polarizing filter. It must be a filter designed for observing and shooting the Sun, made of metal-coated glass or Mylar plastic. Anything else is not safe and likely far too bright.

But you do NOT need the filter for totality.

Remove it … when?

The answer: a minute or so before totality if you want to capture the first diamond ring just before totality officially starts. Set a timer to remind you, as visually it is very difficult to judge the right moment with your unaided eye. The eclipse will start sooner than you expect.

If you have your camera on Auto Exposure, it will compensate just fine for the change in brightness, from the filtered to the unfiltered view.

But don’t leave your unfiltered camera aimed at the Sun. Replace the filter no more than a minute or so after totality and the second diamond ring ends.


Partial Solar Eclipse and Sunspot #2
The partial eclipse of the Sun, October 23, 2014, shot through a mylar filter, on the front of the 66mm f/7 apo refractor shown above (450mm focal length), using a cropped-frame Canon 60Da camera for 1/8000 second exposure at ISO 100. Focus on the sharp tips of the crescent Sun or a sunspot if one is present.

TIP #10: Focus!

Everyone worries about getting the “best exposure.” Don’t! You’ll get great looking telephoto eclipse close-ups with any of a wide range of exposures.

What ruins most eclipse shots, other than filter forgetfulness, is fuzzy images, from either shaky tripods or poor focus.

Focus manually using Live View on the filtered partially eclipsed Sun. Zoom up on the edge of the Sun or sharp tip of the crescent. Re-focus a few minutes before totality, as the changing temperature can shift the focus of long lenses and telescopes.

But you needn’t worry about re-focusing after you remove the filter. The focus will not change with the filter off.


Me at 2006 Eclipse
Me in Libya in 2006 with my eclipse setup: a small telescope on an alt-azimuth mount.

TIP #1 AGAIN: Keep It Simple!

I’ll remind you to keep things simple for a reason other than giving you time to enjoy the view, and that’s mobility.

You might have to move at the last minute to escape clouds. Complex photo gear can be just too much to take down and set up, often with minutes to spare, as many an eclipse chaser can attest is often necessary. Keep your gear light, easy to use, and mobile. Committing to an overly ambitious and inflexible photo plan and rig could be your undoing.

To help ensure success, check out my next blog entry, Top 10 Tips for Practicing for the Eclipse.

By following both my “Ten Tips” advice blogs you should be able to get great eclipse images to wow your friends and fans, all without missing the experience of actually seeing … and feeling … the eclipse.

However … may I recommend …


How to Photograph the Solar Eclipse
My 295-page ebook on photographing the August 21 total eclipse of the Sun is now available. See http://www.amazingsky.com/eclipsebook.html  It covers all techniques, for both stills, time-lapses, and video, from basic to advanced, plus a chapter on image processing. And a chapter on What Can Go Wrong?! The web page has all the details on content, and links to order the book from Apple iBooks Store (for the best image quality and navigation) or as a PDF for all other devices and platforms. Thanks! Clear skies on eclipse day, August 21, 2017.

For much more detailed advice on shooting options and techniques, and for step-by-step tutorials on processing eclipse images, see my 295-page eBook on the subject, available as an iBook for Apple devices and as a PDF for all computers and tablets.

Check it out at my website page

Thanks and clear skies on August 21!

— Alan, June 23, 2017 / © 2017 Alan Dyer / amazingsky.com

 

10 Tips for Terrific Time-Lapses


eMotimo at Dino Park #1

Here are my top tips for shooting terrific still-image nightscapes … and time-lapse movies of the night sky. 

Canon 6D

1. Go for pixel size, not pixel count

When choosing a camera for night sky scenes, the most important characteristic is not number of megapixels. Just the opposite.

The best cameras are usually models with more modest megapixel counts. Each of their individual pixels is larger and so collects more photons in a given exposure time, yielding higher a signal-to-noise ratio – or lower noise, critical for night shooting.

Cameras with pixels (the “pixel pitch”) 6 to 8 microns across are best. Many high-megapixel cameras have tiny 4-micron pixels.

Large-pixel cameras are often the full-frame models, such as the Canon 5D MkIII and 6D, the Nikon D610, D750, and Df, and the Sony a7s and a7S II.

Many “cropped-frame” cameras are now 18- to 24-megapixel models with smaller, noise-prone pixels. They can certainly be used, but will require more care in exposing well at lower ISOs, and in processing to smooth out noise without blurring detail.

Manual Settings

2. Learn to fly on manual

While DSLRs and Compact System Cameras have amazing automatic functions we use none of them at night.

Instead, we use the camera on Manual or Bulb, dialling in shutter speed, aperture and ISO speed manually. We also have to focus manually, using Live View mode to focus on a bright star or distant light.

Learn the tradeoffs involved: Increasing ISO sensitivity of the sensor keeps exposure times down but increases noise. Opening up the lens aperture to f/2 or f/1.4 also keeps exposures short but introduces image-blurring aberrations, especially at the frame corners.

To prevent stars from trailing due to the sky’s motion adhere to the “500 Rule:” the maximum exposure time is roughly 500 divided by the focal length of your lens.

Histogram-Correct

3. Expose to the right 

At night, always give the sensor plenty of signal.

Use whatever combination of shutter speed, aperture and ISO will provide a well-exposed image. The image “histogram,” the graph of number of pixels at each brightness level shown above, should never be slammed to the left.

It should be a well-distributed “mountain range” of pixels, extending well to the right. If the 500 Rule restricts your shutter speed, and your desire for sharp images across the frame demands you shoot at f/2.8 or even slower, then don’t be afraid to bump up the ISO speed to whatever it takes to produce a good histogram and a well-exposed image.

Noise will look far worse if you underexpose, then try to boost the image brightness later in processing. Expose to the right!

File Format #2 7D

4. Shoot Raw!

Shoot Raw. Period.

When comparing Raw and compressed JPG versions of the same image, you can be fooled into thinking the JPGs look better (i.e. smoother) because of the noise reduction the camera has applied to the JPG that is beyond your control. However, that smoothing has also wiped out fine detail, like stars.

By shooting Raw you get to control whatever level of noise reduction and sharpening the image needs later in processing.

JPGs are also 8-bit images with a limited tonal range – or palette – in which to record the subtle gradations of brightness and colour present in our images.

Imported Raw files are 16-bit, with a much wider tonal scale and colour palette. That’s critical for all astrophotos when, even with a well-exposed image, many tonal values are down in the dark end of the range. Processing Raw images makes it possible to extract detail in the shadows and highlights.

Even when shooting a time-lapse sequence, shoot Raw.

LENR

5. Take dark frames (sometimes!)

LENR reduces noise.

It’s a topic of some debate, but in my experience it is always better to turn on the camera’s Long Exposure Noise Reduction (LENR) function when shooting individual nightscape images. Doing so forces the camera to take a “dark frame,” an exposure of equal length but with the shutter closed.

It records just the noise, which the camera then subtracts from the image. Yes, it takes twice as long to acquire an image, but the image is cleaner, with fewer noisy pixels.

This is especially true when shooting on hot summer nights (the warmer the sensor the higher the noise). That said, you cannot use LENR when shooting frames for star trail composites or time-lapse movies.

For those, the interval between images should be no more than 1 to 5 seconds. Using LENR would introduce unsightly gaps in the trails or jumps in the star motion in time-lapses.

As an alternative, it is possible to take separate dark frames at the end of the night by simply covering the lens and taking exposures of the same duration and at the same ISO as your “light frames.”

Some stacking software, such as StarStax and the Advanced Stacker Actions have places to put these dark frames, to subtract them from the stack later in processing.

811eBU4sBkL._SL1500_

6. Use fast lenses

A fast lens is your best accessory.

While the “kit zoom” lenses that come with many DSLRs are great for shooting bright twilight or Full Moon scenes, they will prove too slow for dark starlit scenes with the Milky Way.

In addition to exposing to the right and shooting Raw, the secret to great nightscapes is to shoot with fast lenses, usually “prime” lenses with fixed focal lengths. They are usually faster and have better image quality than zooms.

Your most-used lens for nightscape and time-lapse shooting is likely to be a 14mm to 24mm f/2 to f/2.8 lens.

Fortunately, because we don’t need (and indeed can’t use) autofocus we can live happily with low-cost manual lenses, such as the models made in Korea and sold under brands such as Rokinon, Samyang and Bower. They work very well.

The quarter Moon reflected in the waters of Reesor Lake, Alberta in Cypress Hills Interprovincial Park. Taken on July 5, 2014. This is with the 14mm Rokinon lens and Canon 6D at ISO800. This is a high dynamic range stack of6 exposures from 1/15 to 0.6 seconds taken just before using the camera to take a motion control time-lapse. The Moon was in conjunction with Mars (right of Moon) and Spica (left of Moon) but in the bright twilight they are not showing up here.

7. Get to know the Moon & Milky Way

For many nightscape and time-lapse shoots, the Moon is your light source for illuminating the landscape.

When the Moon is absent, the Milky Way is often your main sky subject.

Knowing where the Moon will be in the sky at its various phases, and when it will rise (in its waning phases after Full Moon) or set (in its waxing phases before Full) helps you a plan a shoot, so you’ll know whether a landscape will be well lit.

Astronomy apps for desktop computers and mobile devices are essential planning aids. A good one specifically for photographers is The Photographer’s Ephemeris.

Knowing in what season and time of night the Milky Way will be visible is essential if you want to capture it. Don’t try for Milky Way shots in spring – it isn’t up!

Me with cameras shooting time-lapses at Crawling Lake reservoir, Alberta, June 30/July 1, 2013. Perpetual twilight of summer solstice shines to the north and very weak noctilucent clouds.

8. Keep it simple to start

Don’t be seduced by the fancy gear. 

Time-lapse imaging has blossomed into a field replete with incredible gear for moving a camera incrementally during a shoot, and for automating a shoot as day turns to night.

I explain how to use all the fancy gear in my ebook, linked to below, however … Great time-lapses, and certainly still-frame nightscapes, can be taken with no more than a DSLR camera with a good fast lens and mounted on a sturdy tripod. Invest in the lens and don’t scrimp on the tripod.

Another essential for shooting multi-frame star trails and time-lapses is a hardware intervalometer ($50 to $150).

TC-80N3 Masked

9. Learn the intricacies of intervals

For time-lapses, an intervalometer is essential.

Mastering exposure and focus in still images is essential for great time-lapse movies because they are simply made of hundreds of well-exposed still frames.

But move to time-lapses and you have additional factors to consider: how many frames to shoot and how often to shoot them. A good rule of thumb is to shoot 200 to 300 frames per sequence, shot with an interval of no more than 1 to 5 seconds between exposures, at least for starry night sequences.

However, most intervalometers (the Canon TC-80N3 is an exception) define their “Interval” setting to mean the time from when the shutter opens to when it opens again. In that case, you set the Interval to be a value 1 to 5 seconds longer than the exposure time you are using. That’s also true of the intervalometer function Nikon builds into their internal camera firmware.

Test first!

The summer Milky Way with a meteor streaking at centre as a bonus. An aurora to the north off frame is lighting the foreground with a green glow. Haze and forest fire smoke obscure the horizon. I shot this at the Battle Scene viewpoint at Writing-on-Stone Provincial Park, in southern Alberta. Sagittarius and the galactic centre is on the horizon at left of centre. Capricornus is amid the haze at left of centre. On the horizon are the Sweetgrass Hills in Montana. The Milk River winds below amid the sandstone formations that are home to historic First Nations petroglyphs.  This is a single 30-second exposure with the Nikon D750 at ISO 3200 and Sigma 24mm Art lens at f/2, taken as part of a time-lapse sequence.

10. Go to beautiful places

While the gear can be simple, great shots demand an investment in time.

By all means practice at home and at nearby sites that are quick to get to. Try out gear and techniques at Full Moon when exposures are short (the Full Moon is bright!) and you can see what you are doing.

But beautiful images of landscapes lit by moonlight or starlight require you to travel to beautiful locations.

When you are on site, take the time to frame the scene well, just as you would during the day. Darkness is no excuse for poor composition!

While shooting nightscapes and time-lapses can be done with a minimal investment in hardware and software, it does require an investment in time – time to travel and spend nights shooting at wonderful places under the stars.

Enjoy the night!

I cover all these topics, and much more, in detail in my ebook How to Photograph & Process Nightscapes and Time-Lapses. Click the link below to learn more.

— Alan, September 16, 2015 / © 2015 Alan Dyer / www.AmazingSky.com