Ten Tips for Taking Time-Lapses


Selfie at Grasslands National Park

I present my top 10 tips for capturing time-lapses of the moving sky. 

If you can take one well-exposed image of a nightscape, you can take 300. There’s little extra work required, just your time. But if you have the patience, the result can be an impressive time-lapse movie of the night sky sweeping over a scenic landscape. It’s that simple. 

Or is it? 

Here are my tips for taking time-lapses, in a series of “Do’s” and “Don’ts” that I’ve found effective for ensuring great results. 

But before you attempt a time-lapse, be sure you can first capture well-exposed and sharply focused still shots. Shooting hundreds of frames for a time-lapse will be a disappointing waste of your time if all the images are dark and blurry. 

For that reason many of my tips apply equally well to shooting still images. But taking time-lapses does require some specialized gear, techniques, planning, and software. First, the equipment. 

NOTE: This article appeared originally in Issue #9 of Dark Sky Travels e-magazine.


SELECTING EQUIPMENT

Camera on Tripod
Essential Gear
Time-lapse photography requires just the camera and lens you might already own, but on a solid tripod (a carbon-fibre Manfrotto with an Acratech ball-head is shown here), and with an intervalometer. 

TIP 1 — DO:  Use a solid tripod 

A lightweight travel tripod that might suffice for still images on the road will likely be insufficient for time-lapses. Not only does the camera have to remain rock steady for the length of the exposure, it has to do so for the length of the entire shoot, which could be several hours. Wind can’t move it, nor any camera handling you might need to do mid-shoot, such as swapping out a battery. 

The tripod needn’t be massive. For hiking into scenic sites you’ll want a lightweight but sturdy tripod. While a carbon fibre unit is costly, you’ll appreciate its low weight and good strength every night in the field. Similarly, don’t scrimp on the tripod head. 

TIP 2 — DO:  Use a fast lens

Csmera on Ball Head
The All-Important Lens
A fast lens is especially critical for time-lapses to allow capturing good sky and ground detail in each exposure, as compositing later won’t be feasible. This is the Sigma 20mm f/1.4 Art lens.

As with nightscape stills, the single best purchase you can make to improve your images of dark sky scenes is not buying a new camera (at least not at first), but buying a fast, wide-angle lens. 

Ditch the slow kit zoom and go for at least an f/2.8, if not f/2, lens with 10mm to 24mm focal length. This becomes especially critical for time-lapses, as the fast aperture allows using short shutter speeds, which in turn allows capturing more frames in a given period of time. That makes for a smoother, slower time-lapse, and a shoot you can finish sooner if desired. 

TIP 3 — DO:  Use an intervalometer

3A-Intervalometer-Canon
Canon intervalometer functions
3B-Intervalometer-Nikon
Nikon intervalometer functions
Intervalometer Trio
Automating the Camera
The intervalometer is also key. For cameras without an internal intervalometer (screens from a Canon and a Nikon are shown above), an outboard unit like one of these, is essential. Be sure to get the model that fits your camera’s remote control jack.

Time-lapses demand the use of an intervalometer to automatically fire the shutter for at least 200 to 300 images for a typical time-lapse. Many cameras have an intervalometer function built into their firmware. The shutter speed is set by using the camera in Manual mode. 

Just be aware that a camera’s 15-second exposure really lasts 16 seconds, while a 30-second shot set in Manual is really a 32-second exposure. 

So in setting the interval to provide one second between shots, as I advise below, you have to set the camera’s internal intervalometer for an interval of 17 seconds (for a shutter speed of 15 seconds) or 33 seconds (for a shutter speed of 30 seconds). It’s an odd quirk I’ve found true of every brand of camera I use or have tested. 

Alternatively, you can set the camera to Bulb and then use an outboard hardware intervalometer (they sell for $60 on up) to control the exposure and fire the shutter. Test your unit. Its interval might need to be set to only one second, or to the exposure time + one second. 

How intervalometers define “Interval” varies annoyingly from brand to brand. Setting the interval incorrectly can result in every other frame being missed and a ruined sequence.


SETTING YOUR CAMERA

TIP 4 — DON’T:  Underexpose

4-Histogram Example
Expose to the Right
When shooting, choose settings that will yield a histogram that is not slammed to the left, but is shifted to the right to minimize noise and lift details in the shadows.

As with still images, the best way to beat noise is to give the camera signal. Use a wider aperture, a longer shutter speed, or a higher ISO (or all of the above) to ensure the image is well exposed with a histogram pushed to the right. 

If you try to boost the image brightness later in processing you’ll introduce not only the very noise you were trying to avoid, but also odd artifacts in the shadows such as banding and purple discolouration. 

With still images we have the option of taking shorter, untrailed images for the sky, and longer exposures for the dark ground to reveal details in the landscape, to composite later. With time-lapses we don’t have that luxury. Each and every frame has to capture the entire scene well. 

At dark sky sites, expose for the dark ground as much as you can, even if that makes the sky overly bright. Unless you outright clip the highlights in the Milky Way or in light polluted horizon glows, you’ll be able to recover highlight details later in processing. 

After poor focus, underexposure, resulting in overly noisy images, is the single biggest mistake I see beginners make.

TIP 5 — DON’T:  Worry about 500 or “NPF” Exposure Rules

Milky Way and ISS over Waterton Lakes
Stills from a Sequence
A stack of single frames from a time-lapse sequence can often make a good still image, such as this scene of the Space Station rising over Waterton Lakes National Park. The 30-second exposures were just within the “500 Rule” for the 15mm lens used here, but minor star trailing won’t be that noticeable in a final movie.

While still images might have to adhere to the “500 Rule” or the stricter “NPF Rule” to avoid star trailing, time-lapses are not so critical. Slight trailing of stars in each frame won’t be noticeable in the final movie when the stars are moving anyway. 

So go for rule-breaking, longer exposures if needed, for example if the aperture needs to be stopped down for increased depth of field and foreground focus. Again, with time-lapses we can’t shoot separate exposures for focus stacking later. 

Just be aware that the longer each exposure is, the longer it will take to shoot 300 of them. 

Why 300? I find 300 frames is a good number to aim for. When assembled into a movie at 30 frames per second (a typical frame rate) your 300-frame clip will last 10 seconds, a decent length of time in a final movie. 

You can use a slower frame rate (24 fps works fine), but below 24 the movie will look jerky unless you employ advanced frame blending techniques. I do that for auroras.

5B-PhotoPills Calculator
PhotoPills Calculator
Apps such as PhotoPills offer handy calculators for juggling exposure time vs. the number of frames to yield the length of the time-lapse shoot.

Bonus Tip

How long it will take to acquire the needed 300 frames will depend on how long each exposure is and the interval between them. An app such as PhotoPills (via its Time lapse function) is handy in the field for calculating exposure time vs. frame count vs. shoot length, and providing a timer to let you know when the shoot is done. 

TIP 6 — DO:  Use short intervals

6A-Intervals-No Gaps

6B-Intervals-Gaps
Mind the Gap!
At night use intervals as short as possible to avoid gaps in time, simulated here (at top) by stacking several time-lapse frames taken at a one-second interval into one image. Using too long an interval, as demonstrated just above, yields gaps in time and jumps in the star motion, simulated here by stacking only every other frame in a sequence. 

At night, the interval between exposures should be no more than one or two seconds. By “interval,” I mean the time between when the shutter closes and when it opens again for the next frame. 

Not all intervalometers define “Interval” that way. But it’s what you expect it means. If you use too long an interval then the stars will appear to jump across the sky, ruining the smooth motion you are after. 

In practice, intervals of four to five seconds are sometimes needed to accommodate the movement of motorized “motion control” devices that turn or slide the camera between each shot. But I’m not covering the use of those advanced units here. I cover those options and much, much more in 400 pages of tips, techniques and tutorials in my Nightscapes ebook, linked to above.

However, during the day or in twilight, intervals can be, and indeed need to be, much longer than the exposures. It’s at night with stars in the sky that you want the shutter to be closed as little as possible. 

TIP 7 — DO:  Shoot Raw

7-Camera Raw Comparison
The Power of Raw
Shooting raw, even for time-lapse frames that will eventually be turned into JPGs, allows for maximum control of shadows, highlights, colour balance, and noise reduction. “Before” is what came out of the camera; “After” is with the development settings shown applied in Camera Raw.

This advice also applies to still images where shooting raw files is essential for professional results. But you likely knew that.

However, with time-lapses some cameras offer a mode that will shoot time-lapse frames and assemble them into a movie right in the camera. Don’t use it. It gives you a finished, pre-baked movie with no ability to process each frame later, an essential step for good night time-lapses. And raw files provide the most data to work with.

So even with time-lapses, shoot raw not JPGs. 

If you are confident the frames will be used only for a time-lapse, you might choose to shoot in a smaller S-Raw or compressed C-Raw mode, for smaller files, in order to fit more frames onto a card. 

But I prefer not to shrink or compress the original raw files in the camera, as some of them might make for an excellent stacked and layered still image where I want the best quality originals (such as for the ISS over Waterton Lakes example above). 

To get you through a long field shoot away from your computer buy more and larger memory cards. You don’t need costly, superfast cards for most time-lapse work. 


PLANNING AND COMPOSITION

TIP 8 — DO:  Use planning apps to frame 

8A-TPE Screen
Planning the Shoot
Apps such as The Photographer’s Ephemeris (shown here set for the author’s Waterton Lakes site for moonrise) help in planning where the Sun, Moon and Milky Way will be from your site during the shoot.
8B-TPE 3D Demo
Simulating the Shoot
The companion app to The Photographer’s Ephemeris, TPE 3D, shown above in the inset, exactly matches the real scene for the mountain skyline, placement of the Milky Way, and lighting from the rising Moon. 

All nightscape photography benefits from using one of the excellent apps we now have to assist us in planning a shoot. They are particularly useful for time-lapses. 

Apps such as PhotoPills and The Photographer’s Ephemeris are great. I like the latter as it links to its companion TPE 3D app to preview what the sky and lighting will look like over the actual topographic horizon from your site. You can scrub through time to see the motion of the Milky Way over the scenery. The Augmented Reality “AR” modes of these apps are also useful, but only once you are on site during the day.

For planning a time-lapse at home I always turn to a “planetarium” program to simulate the motion of the sky (albeit over a generic landscape), with the ability to add in “field of view” indicators to show the view your lens will capture. 

You can step ahead in time to see how the sky will move across your camera frame during the length of the shoot. Indeed, such simulations help you plan how long the shoot needs to last until, for example, the galactic core or Orion sets.

Planetarium software helps ensure you frame the scene properly, not only for the beginning of the shoot (that’s easy — you can see that!), but also for the end of the shoot, which you can only predict. 

8C-Stellarium Start

8D-Stellarium End
Planetarium Planning
An alternative is to use a planetarium program such as the free Stellarium, shown above, which can display lens fields of view. These scenes show the simulated vs. real images (insets) for the start (top) and end (bottom) of the Waterton Lakes time-lapse with a 35mm lens frame, outlined in red. 

To save you from guessing wrong, try the free Stellarium (stellarium.org), or the paid Starry Night (starrynight.com) or SkySafari (skysafariastronomy.com). I use Starry Night. 

Bonus Tip

If your shoot will last as long as three hours, do plan to check the battery level and swap batteries before three hours is up. Most cameras, even new mirrorless models, will now last for three hours on a full battery, but likely not any longer. If it’s a cold winter night, expect only one or two hours of life from a single battery.


PROCESSING

TIP 9 — DO:  Develop one raw frame and apply settings to all

9A-Bridge-Copy

9B-Bridge-Paste
Copy and Paste Settings
Most raw developers or photo library programs (Adobe Bridge is shown here) offer the essential ability to copy settings from one image and paste them onto hundreds of others in a folder, developing all the time-lapse frames in a snap.

Processing the raw files takes the same steps and settings as you would use to process still images. 

With time-lapses, however, you have to do all the processing required within your favourite raw developer software. You can’t count on bringing multiple exposures into a layer-based processor such as Photoshop to stack and blend images. That works for a single image, but not for 300. 

I use Adobe Camera Raw out of Adobe Bridge to do all my time-lapse processing. But many photographers use Lightroom, which offers all the same settings and non-destructive functions as Adobe Camera Raw. 

For those who wish to “avoid Adobe” there are other choices, but for time-lapse work an essential feature is the ability to develop one frame, then copy and paste its settings (or “sync” settings) to all the other frames in the set. 

Not all programs allow that. Affinity Photo does not. Luminar doesn’t do it very well. DxO PhotoLab, ON1 Photo RAW, and the free Raw Therapee, among others, all work fine. 

HOW TO ASSEMBLE A TIME-LAPSE

Once you have a set of raws all developed, the usual workflow is to export all those frames out as high-quality JPGs which is what movie assembly programs need. Your raw developing software has to allow batch exporting to JPGs — most do. 

9C-Image Processor Screen
Photoshop Batch Export
Raw developers usually have a batch export function. So does Photoshop, via its Image Processor utility, shown here (found under File>Scripts>Image Processor) that can export a folder of raws into JPGs or TIFFs, and re-size them, often needed for final 4K or HD movies. 

However, none of the programs above (except Photoshop and Adobe’s After Effects) will create the final movie, whether it be from those JPGs or from the raws. 

9D-TLDF Screen
Assembling JPGs
The author’s favourite assembly program is TimeLapse DeFlicker (TLDF). It can turn a folder of JPGs into movies as large as 8K and with ProRes codecs for the highest quality.

So for assembling the intermediate JPGs into a movie, I often use a low-cost program called TLDF (TimeLapse DeFlicker) available for MacOS and Windows (timelapsedeflicker.com). It offers advanced functions such as deflickering (i.e. smoothing slight frame-to-frame brightness fluctuations) and frame blending (useful to smooth aurora motions or to purposely add star trails).

While there are many choices for time-lapse assembly, I suggest using a program dedicated to the task and not, as many do, a movie editing program. For most sequences, the latter makes assembly unnecessarily difficult and harder to set key parameters such as frame rates. 

TIP 10 — DO:  Try LRTimelapse for more advanced processing

10A-LRT-Bridge Keyframes
Working on Keyframes
The advanced processing program LRTimelapse creates several keyframes through the sequence (seven are shown here in Adobe Bridge) which you develop so each looks its best. During this sequence, the Moon rose changing the lighting toward the end of the shoot (in the last three keyfames). 

Get serious about time-lapse shooting and you will want — indeed, you will need — the program LRTimelapse (LRTimelapse.com). A free but limited trial version is available. 

This powerful program is for sequences where one setting will not work for all the frames. One size does not fit all.

Instead, LRTimelapse allows you to process a few keyframes throughout a sequence, say at the start, middle, and end. It then interpolates all the settings between those keyframes to automatically process the entire set of images to smooth (or “ramp”) and deflicker the transitions from frame to frame. 

10B-LRT-Final Screen
LRTimelapse Ramping
LRTimelapse reads your developed keyframe data and applies smooth transitions of all settings to each of the raw files between the keyframes. The result is a seamless and smooth final movie. The pink curve shows how the scene brightened at moonrise. The blue diamonds on the yellow line mark the seven keyframes. 

This is essential for sequences where the lighting changes during the shoot (say, the Moon rises or sets), and for so-called “holy grails.” Those are advanced sequences that track from daylight or twilight to darkness, or vice versa, over a wide range of camera settings.

However, LRTimelapse works only with Adobe Lightroom or the Adobe Camera Raw/Bridge combination. So for advanced time-lapse work Adobe software is essential. 

A Final Bonus Tip

Keep it simple. You might aspire to emulate the advanced sequences you see on the web, where the camera pans and dollies during the movie. I suggest avoiding complex motion control gear at first to concentrate on getting well-exposed time-lapses with just a static camera. That alone is a rewarding achievement.

But before that, first learn to shoot still images successfully. All the settings and skills you need for a great looking still image are needed for a time-lapse. Then move onto capturing the moving sky. 

I end with a link to an example music video, shot using the techniques I’ve outlined. Thanks for reading and watching. Clear skies!

The Beauty of the Milky Way from Alan Dyer on Vimeo.


© 2019 Alan Dyer

Alan Dyer is author of the comprehensive ebook How to Photograph and Process Nightscapes and Time-Lapses. His website is www.amazingsky.com 

For a channel of his time-lapse movies, music videos, and tutorials on Vimeo see https://vimeo.com/channels/amazingsky 

 

Testing the Nikon Z6 for Astrophotography


Nikon Z Title

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

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

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

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

Sony a7III vs Nikon Z6 copy

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

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


Disclosure

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

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

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

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

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

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


TL;DR Conclusions

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

Nikon Z6 Screens copy

Summary:

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

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

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

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

Recommendations: 

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

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


Nikon Z6 vs. Z7

Nikon Front View copy

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

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

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

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


High ISO Noise

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

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

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

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

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

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

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

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


ISO Invariance

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

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

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

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

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

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

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

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

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

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

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


Compressed vs. Uncompressed / Raw Large vs. Small 

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

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

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

Z6 Menu - Raw Formats

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

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

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

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

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

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


Star Image Quality

Orion Nebula, M42 and M43, with Nikon Z6
The Orion Nebula with the Nikon Z6
The Orion Nebula in Moonlight
The Orion Nebula with the Nikon D750

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

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

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

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


LENR Dark frames 

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

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

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

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

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

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

NOTE:

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

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

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


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

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

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

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

ANOTHER NOTE: 

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

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

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

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


Sensor Illumination 

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

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

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

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

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


Red Sensitivity

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

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

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

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

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


Live View Focusing and Framing 

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

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

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

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

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

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


Video Capability 

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

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

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

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

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

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

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

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


Battery Life

Nikon Z6 Battery copy

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

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

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

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

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

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


Lens and Telescope Compatibility 

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

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

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

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

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

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

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

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

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

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

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


Camera Controller Compatibility 

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

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

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

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

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

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


Raw File Compatibility 

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

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

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

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

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


Other Features for Astrophotography 

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

Nikon with Looking Right copy

Tilting LCD Screen 

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

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

OLED Top Screen (Above)

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

Z6 Menu - Quick Menu

Touch Screen 

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

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

Z6 Menu - Intervalometer

Built-in Intervalometer

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

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

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

Z6 Menu - Silent Shooting

Custom i Menu / Custom Function Buttons 

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

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

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

Nikon Z6-My Menu

My Menu 

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

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

Lighter Weight / Smaller Size

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

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

Electronic Front Curtain Shutter / Silent Shooting 

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

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


What’s Missing for Astrophotography (not much!)

Bulb Timer for Long Exposures

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

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

Z6 Menu - Multiple Exposures

In-Camera Image Stacking to Raws

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

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

Illuminated Buttons 

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


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

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

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

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

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

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

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

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


Recommendations 

I was impressed with the Z6. 

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

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

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

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

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

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

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

I highly recommend the Nikon Z6. 

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

 

 

Testing the Venus Optics 15mm Lens


Laowa Test Title

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

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

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


TL;DR Conclusions

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

I use it a lot and highly recommend it.


Size and Weight

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

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

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

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

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

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

Sigma 14mm vs Laowa 15mm Sigma 14mm f/1.8 Art lens (for Nikon mount) vs. Venus Optics 15mm f/2 lens (for Sony mount). © 2019 Alan Dyer

While compact, at 600 grams the Laowa 15mm is quite hefty for its size due to its solid metal construction. Nevertheless, it is half the weight of the massive 1250-gram Sigma 14mm f/1.8 Art. The Laowa is not a plastic entry-level lens, nor is it cheap, at $850 from U.S. sources.

For me, the Sony-Laowa combination is my first choice for a lightweight travel camera for overseas aurora trips

Laowa 15mm Back View The lens mount showing no electrical contacts to transfer lens metadata to the camera. © 2019 Alan Dyer

However, this is a no-frills manual focus lens. Nor does it even transfer aperture data to the camera, which is a pity. There are no electrical connections between the lens and camera.

However, for nightscape work where all settings are adjusted manually, the Venus Optics 15mm works just fine. The key factor is how good are the optics. I’m happy to report that they are very good indeed.


Testing Under the Stars

To test the Venus Optics lens I shot “same night” images, all tracked, with the Sigma 14mm f/1.8 Art lens, at left, and the Rokinon 14mm SP (labeled as being f/2.4, at right). Both are much larger lenses, made for DSLRs, with bulbous front elements not able to accept filters. But they are both superb lenses. See my test report on these lenses published in 2018.

Sigma and Rokinon 14mm The Sigma 14mm f/1.8 Art lens (left) vs. the Rokinon SP 14mm f/2.4. © 2019 Alan Dyer

The next images show blow-ups of the same scene (the nightscape shown in full below, taken at Dinosaur Provincial Park, Alberta), and all taken on a tracker.

I used the Rokinon on the Sony a7III using the Metabones adapter which, unlike some brands of lens adapters, does not compromise the optical quality of the lens by shifting its focal position. But lacking a lens adapter for Nikon-to-Sony at the time of testing, I used the Nikon-mount Sigma lens on a Nikon D750, a DSLR camera with nearly identical sensor specs to the Sony.


Vignetting

Laowa 15mm @ f2 A tracked image with the Venus Optics Laowa 15mm at f/2. Click or tap on an image to download a full-resolution JPG for closer inspection.

Above is a tracked image (so the stars are not trailed, which would make it hard to tell aberrations from trails), taken wide open at f/2. No lens correction has been applied so the vignetting (the darkening of the frame corners) is as the lens provides.

As shown above, when used wide open at f/2 vignetting is significant, but not much more so than with competitive lenses with much larger lenses, as I compare below.

And the vignetting is correctable in processing. Adobe Camera Raw and Lightroom have this lens in their lens profile database. That’s not the case with current versions (as of April 2019) of other raw developers such as DxO PhotoLab, ON1 Photo RAW, and Raw Therapee where vignetting corrections have to be dialled in manually by eye.

Laowa 15mm @ f2.8 A tracked image with the Venus Optics Laowa 15mm stopped down 1 stop to f/2.8.

When stopped down to f/2.8 the Laowa “flattens” out a lot for vignetting and uniformity of frame illumination. Corner aberrations also improve but are still present. I show those in close-up detail below.

Lens Comparison - Vignetting 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the left side of the image for vignetting (light fall-off), wide open and stopped down. ©2018 Alan Dyer

Above, I compare the vignetting of the three lenses, both wide open and when stopped down. Wide open, all the lenses, even the Sigma and Rokinon despite their large front elements, show quite a bit of drop off in illumination at the corners.

The Rokinon SP actually seems to be the worst of the trio, showing some residual vignetting even at f/2.8, while it is reduced significantly in the Laowa and Sigma lenses. Oddly, the Rokinon SP, even though it is labeled as f/2.4, seemed to open to f/2.2, at least as indicated by the aperture metadata.


On-Axis Performance

Lens Comparison - Centre 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the centre of the image for sharpness, wide open and stopped down. Click or tap on an image to download a full-resolution JPG for closer inspection. © 2018 Alan Dyer

Above I show lens sharpness on-axis, both wide open and stopped down, to check for spherical and chromatic aberrations with the bright blue star Vega centered. The red box in the Navigator window at top right indicates what portion of the frame I am showing, at 200% magnification in Photoshop.

On-axis, the Venus Optics 15mm shows stars just as sharply as the premium Sigma and Rokinon lenses, with no sign of blurring spherical aberration nor coloured haloes from chromatic aberration.

Laowa 15mm Side with Focus Point This is where this lens reaches sharpest focus on stars, just shy of the Infinity mark. © 2019 Alan Dyer

Focusing is precise and easy to achieve with the Sony on Live View. My unit reaches sharpest focus on stars with the lens set just shy of the middle of the infinity symbol. This  is consistent and allows me to preset focus just by dialing the focus ring, handy for shooting auroras at -35° C, when I prefer to minimize fussing with camera settings, thank you very much!


Off-Axis Performance

Lens Comparison - Upper Left 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the centre of the image for sharpness, wide open and stopped down. Click or tap on an image to download a full-resolution JPG for closer inspection. © 2018 Alan Dyer
Lens Comparison - Upper Right 15mm Laowa vs. Rokinon 14mm SP vs. Sigma Art 14mm – Comparing the upper right corner of the image for aberrations, wide open and stopped down. © 2018 Alan Dyer

The Laowa and Sigma lenses show similar levels of off-axis coma and astigmatism, with the Laowa exhibiting slightly more lateral chromatic aberration than the Sigma. Both improve a lot when stopped down one stop, but aberrations are still present though to a lesser degree.

However, I find that the Laowa 15mm performs as well as the Sigma 14mm Art for star quality on- and off-axis. And that’s a high standard to match.

The Rokinon SP is the worst of the trio, showing significant elongation of off-axis star images (they look like lines aimed at the frame centre), likely due to astigmatism. With the 14mm SP, this aberration was still present at f/2.8, and was worse at the upper right corner than at the upper left corner, an indication to me that even the premium Rokinon SP lens exhibits slight lens de-centering, an issue users have often found with other Rokinon lenses.


Real-World Examples – The Milky Way

Sweep of the Autumn Milky Way This is a stack of 8 x 2-minute exposures with the Venus Optics Laowa 15mm lens at f/2 and Sony a7III at ISO 800, on the Sky-Watcher Star Adventurer tracker. A single exposure taken through the Kenko Softon A filter layered in with Lighten mode adds the star glows, though exaggerates the lens distortion on the bright stars.
Mars and the Milky Way over Writing-on-Stone This is a stack of 12 exposures for the ground, mean combined to smooth noise, and one exposure for the sky, all 30 seconds at f/2 with the Laowa 15mm lens on the Sony a7III camera at ISO 6400. These were the last frames in a 340-frame time-lapse sequence.

The fast speed of the Laowa 15mm is ideal for shooting tracked wide-field images of the Milky Way, and untracked camera-on-tripod nightscapes and time-lapses of the Milky Way.

Image aberrations are very acceptable at f/2, a speed that allows shutter speed and ISO to be kept lower for minimal star trailing and noise while ensuring a well-exposed frame.


Real World Examples – Auroras

Coloured Curtains over CNSC (Feb 9, 2019) Aurora over the Churchill Northern Studies Centre, Churchill, Manitoba. This is 6 seconds at f/2 with the 15mm Venus Optic lens and Sony a7III at ISO 3200.
Sky-Filling Aurora at Tibbitt Lake Aurora from near Yellowknife, NWT, September 8, 2018. This is 2.5-seconds at f/2 with the Venus Optics 15mm lens and Sony a7IIII at ISO 3200.
Aurora from at Sea Near Lofotens #1 The Northern Lights from at sea when leaving the Lofoten Islands, Norway heading toward the mainlaind, from Stamsund to Bodo, March 3, 2019. This was from the Hurtigruten ship the ms Trollfjord. This is a single 1-second exposure for at f/2 with the 15mm Venus Optics lens and Sony a7III at ISO 6400.

Where the Laowa 15mm really shines is for auroras. On my trips to chase the Northern Lights I often take nothing but the Sony-Laowa pair, to keep weight and size down.

Above is an example, taken from a moving ship off the coast of Norway. The fast f/2 speed (I wish it were even faster!) makes it possible to capture the Lights in only 1- or 2-second exposures, albeit at ISO 6400. But the fast shutter speed is needed for minimizing ship movement.


Video Links

The Sony also excels at real-time 4K video, able to shoot at ISO 12,800 to 51,200 without excessive noise.

Aurora Reflections from Alan Dyer on Vimeo.

The Sky is Dancing from Alan Dyer on Vimeo.

The Northern Lights At Sea from Alan Dyer on Vimeo.

Examples of my aurora videos shot with the Sony and Venus Optics 15mm lens are in previous blogs from Yellowknife, NWT in September 2018, from Churchill, Manitoba in February 2019, and from at sea in Norway in March 2019.

Click through to see the posts and the videos shot with the Venus Optics 15mm.

As an aid to video use, the aperture ring of the Venus Optics 15mm can be “de-clicked” at the flick of a switch, allowing users to smoothly adjust the iris during shooting, avoiding audible clicks and jumps in brightness. That’s a very nice feature indeed.

In all, I can recommend the Venus Optics Laowa 15mm lens as a great match to Sony mirrorless cameras, for nightscape still and video shooting. UPDATE: Versions for Canon R and Nikon Z mount mirrorless cameras will now be available.

— Alan, April 20, 2019 / © 2019 Alan Dyer / AmazingSky.com

Testing ON1 Photo RAW for Astrophotography


ON1 Testing Title

Can the new version of ON1 Photo RAW match Photoshop for astrophotography? 

The short TL;DR answer: No.

But … as always, it depends. So do read on.


Released in mid-November 2018, the latest version of ON1 Photo RAW greatly improves a non-destructive workflow. Combining Browsing, Cataloging, Raw Developing, with newly improved Layers capabilities, ON1 is out to compete with Adobe’s Creative Cloud photo suite – Lightroom, Camera Raw, Bridge, and Photoshop – for those looking for a non-subscription alternative.

Many reviewers love the new ON1 – for “normal” photography.

But can it replace Adobe for night sky photos? I put ON1 Photo RAW 2019 through its paces for the demanding tasks of processing nightscapes, time-lapses, and deep-sky astrophotos.


The Conclusions

In my eBook “How to Photograph and Process Nightscapes and Time-Lapses” (linked to at right) I present dozens of processing tutorials, including several on how to use ON1 Photo RAW, but the 2018 edition. I was critical of many aspects of the old version, primarily of its destructive workflow when going from its Develop and Effects modules to the limited Layers module of the 2018 edition.

I’m glad to see many of the shortfalls have been addressed, with the 2019 edition offering a much better workflow allowing layering of raw images while maintaining access to all the original raw settings and adjustments. You no longer have to flatten and commit to image settings to layer them for composites. When working with Layers you are no longer locked out of key functions such as cropping.

I won’t detail all the changes to ON1 2019 but they are significant and welcome.

The question I had was: Are they enough for high-quality astrophotos in a non-destructive workflow, Adobe Photoshop’s forté.

While ON1 Photo RAW 2019 is much better, I concluded it still isn’t a full replacement of Adobe’s Creative Cloud suite, as least not for astrophotography.

NOTE: All images can be downloaded as high-res versions for closer inspection. 


ON1 2019 is Better, But for Astrophotography …

  1. Functions in Layers are still limited. For example, there is no stacking and averaging for noise smoothing. Affinity Photo has those.
  2. Filters, though abundant for artistic special effect “looks,” are limited in basic but essential functions. There is no Median filter, for one.
  3. Despite a proliferation of contrast controls, for deep-sky images (nebulas and galaxies) I was still not able to achieve the quality of images I’ve been used to with Photoshop.
  4. The lack of support for third-party plug-ins means ON1 cannot work with essential time-lapse programs such as Timelapse Workflow or LRTimelapse.
ON1 Final Composite
A finished nightscape composite, with stacked exposures for the ground and stacked and tracked exposures for the sky, layered and blended in ON1.

Recommendations

Nightscapes: ON1 Photo RAW 2019 works acceptably well for nightscape still images:

  1. Its improved layering and excellent masking functions are great for blending separate ground and sky images, or for applying masked adjustments to selected areas.

Time-Lapses: ON1 works is just adequate for basic time-lapse processing:

  1. Yes, you can develop one image and apply its settings to hundreds of images in a set, then export them for assembly into a movie. But there is no way to vary those settings over time, as you can by mating Lightroom to LRTimelapse.
  2. As with the 2018 edition, you still cannot copy and paste masked local adjustments from image to image, limiting their use.
  3. Exporting those images is slow.

Deep-Sky: ON1 is not a program I can recommend for deep-sky image processing:

  1. Stars inevitably end up with unsightly sharpening haloes.
  2. De-Bayering artifacts add blocky textures to the sky background.
  3. And all the contrast controls still don’t provide the “snap” and quality I’m used to with Photoshop when working with low-contrast subjects.

Library / Browse Functions

ON1 Browse Module
ON1 cannot catalog or display movie files or Photoshop’s PSB files (but then again with PSBs neither can Lightroom!).

ON1 is sold first and foremost as a replacement for Adobe Lightroom, and to that extent it can work well. Unlike Lightroom, ON1 allows browsing and working on images without having to import them formally into a catalog.

However, you can create a catalog if you wish, one that can be viewed even if the original images are not “on-line.” The mystery seems to be where ON1 puts its catalog file on your hard drive. I was not able to find it, to manually back it up. Other programs, such as Lightroom and Capture One, locate their catalogs out in the open in the Pictures folder.

For those really wanting a divorce from Adobe, ON1 now offers an intelligent AI-based function for importing Lightroom catalogs and transferring all your Lightroom settings you’ve applied to raw files to ON1’s equivalent controls.

However, while ON1 can read Photoshop PSD files, it will flatten them, so you would lose access to all the original image layers.

ON1’s Browse module is good, with many of the same functions as Lightroom, such as “smart collections.” Affinity Photo – perhaps ON1’s closest competitor as a Photoshop replacement – still lacks anything like it.

But I found ON1’s Browse module buggy, often taking a long while to allow access into a folder, presumably while it is rendering image previews.

There are no plug-ins or extensions for exporting directly to or synching to social media and photo sharing sites.


Nightscape Processing – Developing Raw Images

ON1 Before and After Processing
On the left, a raw image as it came out of the camera. On the right, after developing (with Develop and Effects module settings applied) in ON1.

For this test I used the same nightscape image I threw at Adobe competitors a year ago, in a test of a dozen or more raw developers. It is a 2-minute tracked exposure with a Sigma 20mm Art lens at f/2 and Nikon D750 at ISO 1600.

ON1 did a fairly good job. Some of its special effect filters, such a Dynamic Contrast, Glow, and Sunshine, can help bring out the Milky Way, though do add an artistic “look” to an image which you might or might not like.

Below, I compare Adobe Camera Raw (ACR) to ON1. It was tough to get ON1’s image looking the same as ACR’s result, but then again, perhaps that’s not the point. Does it just look good? Yes, it does.

ON1 & ACR Raw Image Comparison
On the left, a single raw image developed with Adobe Camera Raw. On the right, the same image with ON1 and its basic Develop and more advanced Effects settings.

Compared to Adobe Camera Raw, which has a good array of basic settings, ON1 has most of those and more, in the form of many special Effects, with many combined as one-click Presets, as shown below.

ON1 Presets
ON1 offers a huge array of Presets that apply combinations of its filters with one click from the Browse module.

A few presets and individual filters – the aforementioned Dynamic Contrast and Glow – are valuable. However, most of ON1’s filters and presets will not be useful for astrophotography, unless you are after highly artistic and unnatural effects.

Noise Reduction and Lens Correction

ON1 Noise Reduction
On the left, an image in ON1 without any Noise Reduction. On the right, with noise reduction and sharpening (under Details) applied with the settings shown.

Critical to all astrophotography is excellent noise reduction. ON1 does a fine job here, with good smoothing of noise without harming details.

Lens Correction works OK. It detected the 20mm Sigma art lens and automatically applied distortion correction, but not any vignetting (light “fall-off”) correction, perhaps the most important correction in nightscape work. You have to dial this in manually by eye, a major deficiency.

By comparison, ACR applies both distortion and vignetting correction automatically. It also includes settings for many manual lenses that you can select and apply in a click. For example, ACR (and Lightroom) includes settings for popular Rokinon and Venus Optics manual lenses; ON1 does not.

Hot Pixel Removal

Hot Pixel Removal Comparison
On the left, ACR with noise reduction applied (it offers no user-selectable Hot Pixel Removal tool). In the middle, ON1 with Remove Hot Pixels turned on; on the right, with it turned off – showing more hot pixels than ACR does.

I shot the example image on a warm summer night and without using in-camera Long Exposure Noise Reduction (to keep the gap between exposures short when shooting sets of tracked and untracked exposures for later compositing).

However, the penalty for not using LENR to expedite the image taking is a ground filled with hot pixels. While Adobe Camera Raw does have some level of hot pixel removal working “under the hood,” many specks remained.

ON1 showed more hot pixels, until you clicked Remove Hot Pixels, found under Details. As shown at centre above, it did a decent job getting rid of the worst offenders.

But as I’ll show later, the penalty is that stars now look distorted and sometimes double, or you get the outright removal of stars. ON1 doesn’t do a good job distinguishing between true sharp-edged hot pixels and the softer images of stars. Indeed, it tends to over sharpen stars.

A competitor, Capture One 11, does a better job, with an adjustable Single Pixel removal slider, so you can at least select the level of star loss you are willing to tolerate to get rid of hot pixels.

Star Image Quality

ON1 & ACR Star Image Comparison
On the left, a 700% blow-up of the stars in Adobe Camera Raw. On the right, the same image processed in ON1 and exported out as a PSD.

Yes, we are pixel peeping here, but that’s what we do in astrophotography. A lot!

Stars in ON1 don’t look as good as in Camera Raw. Inevitably, as you add contrast enhancements, stars in ON1 start to exhibit dark and unsightly “sharpening haloes” not present in ACR, despite me applying similar levels of sharpening and contrast boosts to each version of the image.

Camera Raw has been accused of producing images that are not as sharp as with other programs such as Capture One and ON1.

There’s a reason. Other programs over-sharpen, and it shows here.

We can get away with it here in wide-field images, but not later with deep-sky close-ups. I don’t like it. And it is unavoidable. The haloes are there, albeit at a low level, even with no sharpening or contrast enhancements applied, and no matter what image profile is selected (I used ON1 Standard throughout).

De-Bayering Artifacts

ON1-Debayer
ON1, with contrast boosts applied but with no sharpening or noise reduction, shows star haloes, while the sky shows a blocky pattern at the pixel level in high ISO shots.
ACR-Debayer
Adobe Camera Raw, with similar settings but also no sharpening or noise reduction, shows a smooth and uniform sky background.

You might have to download and closely inspect these images to see the effect, but ON1’s de-Bayering routine exhibits a cross-hatched blocky pattern at the pixel-peeping level. ACR does not.

I see this same effect with some other raw developers. For example, the free Raw Therapee shows it with many of its choices for de-Bayering algorithms, but not all. Of the more than a dozen raw developers I tested a year ago, ACR and DxO PhotoLab had (and still have) the most artifact-free de-Bayering and smoothest noise reduction

Again, we can get away with some pixel-level artifacts here, but not later, in deep-sky processing.


Nightscape Processing — Layering and Compositing

ON1 Perfect Brush
ON1’s adjustable “Perfect Brush” option for precise masking around edges and objects isn’t quite as effective as Photoshop’s Quick Selection Tool.

Compositing

The 2018 version of ON1 forced you to destructively flatten images when bringing them into the Layers module.

The 2019 version of ON1 improves that. It is now possible to composite several raw files into one image and still retain all the original Develop and Effects settings for non-destructive work.

You can then use a range of masking tools to mask in or out the sky.

For the example above, I have stacked tracked and untracked exposures, and am starting to mask out the trailed stars from the untracked exposure layer.

To do this with Adobe, you would have to open the developed raw files in Photoshop (ideally using “smart objects” to retain the link back to the raw files). But with ON1 we stay within the same program, to retain access to non-destructive settings. Very nice!

To add masks, ON1 2019 does not have the equivalent of Photoshop’s excellent Quick Selection Tool for selecting the sky or ground. It does have a “Perfect Brush” option which uses the tonal value of the pixels below it, rather than detecting edges, to avoid “painting over the lines.”

While the Perfect Brush does a decent job, it still requires a lot of hand painting to create an accurate mask without holes and defects. There is no non-destructive “Select and Mask” refinement option as in Photoshop.

Yes, ON1’s Refine Brush and Chisel Mask tools can help clean up a mask edge but are destructive to the mask. That’s not acceptable to my non-destructive mindset!

Local Adjustments 

ON1 Masking Adjustments
Local Adjustments can be painted in or out with classic and easy-to-adjust and view masks and layers, rather than adjustment pins used by many raw developers such as ACR.

The masking tools are also applicable to adding “Local Adjustments” to any image layer, to brighten or darken regions of an image for example.

These work well and I find them more intuitive than the “pins” ACR uses on raw files, or DxO PhotoLab’s quirky “U-Point” interface.

ON1’s Local Adjustments work more like Photoshop’s Adjustment Layers and are similarly non-destructive. Excellent.

Luminosity Masks

ON1 Luminosity Masking
ON1 has one-click Luminosity masking, an excellent feature.

A very powerful feature of ON1 is its built-in Luminosity masking.

Yes, Camera Raw now has Range Masks, and Photoshop can be used to create luminosity masks, but making Photoshop’s luminosity masks easily adjustable requires purchasing third-party extension panels.

ON1 can create an adjustable and non-destructive luminosity mask on any image or adjustment layer with a click.

While such masks, based on the brightness of areas, aren’t so useful for low-contrast images like the Milky Way scene above, they can be very powerful for merging high-contrast images (though ON1 also has an HDR function not tested here).

Glow Effect
ON1’s handy Orton-style Glow effect, here with a Luminosity mask applied. The mask can be adjusted with the Levels and Window sliders, and applied to a range of colors as well.

ON1 has the advantage here. Its Luminosity masks are a great feature for compositing exposures or for working on regions of bright and dark in an image.

Final Composite

ON1 Final Composite
A finished nightscape composite, with stacked exposures for the ground and stacked and tracked exposures for the sky, layered and blended in ON1.

Here again is the final result, above.

It is not just one image each for the sky and ground, but is instead a stack of four images for each half of the composite, to smooth noise. This form of stacking is somewhat unique to astrophotography, and is commonly used to reduce noise in nightscapes and in deep-sky images, as shown later.

Stacking

ON1-Layer Opacities
This shows an intermediate step in creating the final composite shown above: Four sky layers are stacked, with opacities as shown, which has the effect of smoothing noise. But to continue working on the image requires making a single “New Stamped Layer” out of the group of four – in this case, the sky layers. The same can be done for the four ground layers.

Here I show how you have to stack images in ON1.

Unlike Photoshop and Affinity Photo, ON1 does not have the ability to merge images automatically into a stack and apply a mathematical averaging to the stack, usually a Mean or Median stack mode. The averaging of the image content is what reduces the random noise.

Instead, with ON1 you have perform an “old school” method of average stacking – by changing the opacity of the layers, so that Layer 2 = 50%, Layer 3 = 33%, Layer 4 = 25%, and so on. The result is identical to performing a Mean stack mode in Photoshop or Affinity.

Fine, except there is no way to perform a Median stack, which can be helpful for eliminating odd elements present in only one frame, perhaps an aircraft trail.

Copy and Paste Settings

ON1 Pasting Settings
ON1 allows easy copying and pasting of settings from one raw image to others, with the annoying exception of Local Adjustments and their masks.

Before we even get to the stacking stage, we have to develop and process all the images in a set. Unlike Lightroom or Camera Raw, ON1 can’t develop and synchronize settings to a set of images at once. You can work on only one image at a time.

So, you work on one image (one of the sky images here), then Copy and Paste its settings to the other images in the set. I show the Paste dialog box here.

This works OK, though I did find some bugs – the masks for some global Effects layers did not copy properly; they copied inverted, as black instead of white masks.

However, Luminosity masks did copy from image to image, which is surprising considering the next point.

The greater limitation is that no Local Adjustments (ones with masks to paint in a correction to a selected area) copy from one image to another … except ones with gradient masks. Why the restriction?

So as wonderful as ON1’s masking tools might be, they aren’t of any use if you want to copy their masked adjustments across several images, or, as shown next, to a large time-lapse set.

While Camera Raw’s and Lightroom’s Local Adjustment pins are more awkward to work with, they do copy across as many images as you like.


Time-Lapse Processing

ON1 Copy & Paste
ON1 does allow developing one image in a set, then copying and pasting its settings to perhaps hundreds of other images in a time-lapse set.

A few Adobe competitors, such as Affinity Photo (as of this writing) simply can’t do this.

By comparison, with the exception of Local Adjustments, ON1 does have good functions for Copying and Pasting Settings. These are essential for processing a set of hundreds of time-lapse frames.

ON1 Export
This is ON1’s Export dialog box, set up here to export the developed raw files into another “intermediate” set of 4K-sized JPGs for movie assembly.

Once all the images are processed – whether it be with ON1 or any other program – the frames have to exported out to an intermediate set of JPGs for assembly into a movie by third-party software. ON1 itself can’t assemble movies, but then again neither can Lightroom (as least not very well), though Photoshop can, through its video editing functions.

For my test set of 220 frames, each with several masked Effects layers, ON1 took 2 hours and 40 minutes to perform the export to 4K JPGs. Photoshop, through its Image Processor utility, took 1 hour and 30 minutes to export the same set, developed similarly and with several local adjustment pins.

ON1 did the job but was slow.

A greater limitation is that, unlike Lightroom, ON1 does not accept any third party plug-ins (it serves as a plug-in for other programs). That means ON1 is not compatible with what I feel are essential programs for advanced time-lapse processing: either Timelapse Workflow (from https://www.timelapseworkflow.com) or the industry-standard LRTimelapse (from https://lrtimelapse.com).

Both programs work with Lightroom to perform incremental adjustments to settings over a set of images, based on the settings of several keyframes.

Lacking the ability to work with these programs means ON1 is not a program for serious and professional time-lapse processing.


Deep-Sky Processing

ON1-Tracked Milky Way
A tracked 2-minute exposure of the Cygnus Milky Way, with a Sony a7III camera at ISO 800 and Venus Optics Laowa 15mm lens at f/2, developed in ON1.
ACR-Tracked Milky Way
The same Milky Way image developed in Adobe Camera Raw. It looks better!

Wide-Angle Milky Way

Now we come to the most demanding task: processing long exposures of the deep-sky, such as wide-angle Milky Way shots and close-ups of nebulas and galaxies taken through telescopes. All require applying generous levels of contrast enhancement.

As the above example shows, try as I might, I could not get my test image of the Milky Way to look as good with ON1 as it did with Adobe Camera Raw. Despite the many ways to increase contrast in ON1 (Contrast, Midtones, Curves, Structure, Haze, Dynamic Contrast and more!), the result still looked flat and with more prominent sky gradients than with ACR.

And remember, with ACR that’s just the start of a processing workflow. You can then take the developed raw file into Photoshop for even more precise work.

With ON1, its effects and filters all you have to work with. Yes, that simplifies the workflow, but its choices are more limited than with Photoshop, despite ON1’s huge number of Presets.

Deep-Sky Close-Ups

ON1 Processed M31
The Andromeda Galaxy, in a stack of six tracked and auto-guided 8-minute exposures with a stock Canon 6D MkII through an 80mm f/6 refractor.
Photoshop Processed M31
The same set of six exposures, stacked and processed with ACR and Photoshop, with multiple masked adjustment layers as at right. The result looks better.

Similarly, taking a popular deep-sky subject, the Andromeda Galaxy, aka M31, and processing the same original images with ON1 and ACR/Photoshop resulted in what I think is a better-looking result with Photoshop.

Of course, it’s possible to change the look of such highly processed images with the application of various Curves and masked adjustment layers. And I’m more expert with Photoshop than with ON1.

But … as with the Cygnus Milky Way image, I just couldn’t get Andromeda looking as good in ON1. It always looked a little flat.

Dynamic Contrast did help snap up the galaxy’s dark lanes, but at the cost of “crunchy” stars, as I show next. A luminosity “star mask” might help protect the stars, but I think the background sky will inevitably suffer from the de-Bayering artifacts.

Star and Background Sky Image Quality

ON1 Processed M31-Close-Up
A 400% close-up of the final Andromeda Galaxy image. It shows haloed stars and a textured and noisy sky background.
Photoshop Processed M31-Close-Up
The same area blown up 400% of the Photoshop version of the Andromeda Galaxy image. Stars and sky look smoother and more natural.

As I showed with the nightscape image, stars in ON1 end up looking too “crunchy,” with dark halos from over sharpening, and also with the blocky de-Bayering artifacts now showing up in the sky.

I feel it is not possible to avoid dark star haloes, as any application of contrast enhancements, so essential for these types of objects, brings them out, even if you back off sharpening at the raw development stage, or apply star masks.

ON1 Processed M31-With & Without
On the left, the image before any processing applied; on the right, after the level of processing needed for such deep-sky images. What starts out looking OK, turns messy.

ON1 is applying too much sharpening “under the hood.” That might “wow” casual daytime photographers into thinking ON1 is making their photos look better, but it is detrimental to deep-sky images. Star haloes are a sign of poor processing.

Noise and Hot Pixels

ON1 With & Without NR and Hot Pixels
With and without noise reduction and hot pixel removal shows stars becoming lost and misshapen with the Remove Hot Pixel option.

ON1’s noise reduction is quite good, and by itself does little harm to image details.

But turn on the Remove Hot Pixel button and stars start to be eaten. Faint stars fade out and brighter stars get distorted into double shapes or have holes in them.

Hot pixel removal is a nice option to have, but for these types of images it does too much harm to be useful. Use LENR or take dark frames, best practices in any case.

Image Alignment and Registration

ON1 Auto-Alignment
The six Andromeda images stacked then “Auto-Aligned” in ON1, with just the top (first) and bottom (last) images turned on here. with the top image switched to Difference blend mode to show any mis-alignment.
Photoshop Auto-Alignment
The same set stacked and “Auto-Aligned” in Photoshop, with the same first and last images turned on and blended with Difference. PS’s alignment is much better, indicated by the image “blacking out” as the two registered frames cancel out.

Before any processing of deep-sky images is possible, it is first necessary to stack and align them, to make up for slight shifts from image to image, usually due to the mount not being perfectly polar aligned. Such shifts can be both translational (left-right, up-down) and rotational (turning about the guide star).

New to ON1 2019 is an Auto-Align Layers function. It worked OK but not nearly as well as Photoshop’s routine. In my test images of M31, ON1 didn’t perform enough rotation.

Once stacked and aligned, and as I showed above, you then have to manually change the opacities of each layer to blend them for noise smoothing.

By comparison, Photoshop has a wonderful Statistics script (under File>Scripts) that will automatically stack, align, then mean or median average the images, and turn the result into a non-destructive smart object, all in one fell swoop. I use it all the time for deep-sky images. There’s no need for separate programs such as Deep-Sky Stacker.

In ON1, however, all that has to be done manually, step-by-step. ON1 does do the job, just not as well.


Wrap-Up

M31 from ON1
The final M31, Andromeda Galaxy image processed with ON1.

ON1 Photo RAW 2019 is a major improvement, primarily in providing a more seamless and less destructive workflow.

Think of it as Lightroom with Layers! 

But it isn’t Photoshop.

Dynamic Contrast
ON1’s useful Dynamic Contrast filter. A little goes a long way.

True to ON1’s heritage as a special effect plug-in, it has some fine Effect filters, such as Dynamic Contrast above, ones I sometimes use from within Photoshop as plug-in smart filters.

Under Sharpen, ON1 does offer a High Pass option, a popular method for sharpening deep-sky objects.

Missing Filters and Adjustments

But for astrophoto use, ON1 is missing a lot of basic but essential filters for pixel-level touch-ups. Here’s a short list:

• Missing are Median, Dust & Scratches, Radial Blur, Shake Reduction, and Smart Sharpen, just to mention a handful of filters I find useful for astrophotography, among the dozens of others Photoshop has, but ON1 does not. But then again, neither does Lightroom, another example of how ON1 is more light Lightroom with layers and not Photoshop.

ON1 Color Adjustment
ON1’s selective Color Adjustment. OK, but where’s the Black and Neutrals?

• While ON1 has many basic adjustments for color and contrast, its version of Photoshop’s Selective Color lacks Neutral or Black sliders, great for making fine changes to color balance in astrophotos.

• While there is a Curves panel, it has no equivalent to Photoshop’s “Targeted Adjustment Tool” for clicking on a region of an image to automatically add an inflection point at the right spot on the curve. This is immensely useful for deep-sky images.

• Also lacking is a basic Levels adjustment. I can live without it, but most astrophotographers would find this a deal-breaker.

• On the other hand, hard-core deep-sky photographers who do most of their processing in specialized programs such as PixInsight, using Photoshop or Lightroom only to perform final touch-ups, might find ON1 perfectly fine. Try it!

Saving and Exporting

ON1 saves its layered images as proprietary .onphoto files and does so automatically. There is no Save command, only a final Export command. As such it is possible to make changes you then decide you don’t like … but too late! The image has already been saved, writing over your earlier good version. Nor can you Save As … a file name of your choice. Annoying!

Opening a layered .onphoto file (even with ON1 itself already open) can take a minute or more for it to render and become editable.

Once you are happy with an image, you can Export the final .onphoto version as a layered .PSD file but the masks ON1 exports to the Photoshop layers may not match the ones you had back in ON1 for opacity. So the exported .PSD file doesn’t look like what you were working on. That’s a bug.

Only exporting a flattened TIFF file gets you a result that matches your ON1 file, but it is now flattened.

Bugs and Cost

I encountered a number of other bugs, ones bad enough to lock up ON1 now and then. I’ve even seen ON1’s own gurus encounter bugs with masking during their live tutorials. These will no doubt get fixed in 2019.x upgrades over the next few months.

But by late 2019 we will no doubt be offered ON1 Photo RAW 2020 for another $80 upgrade fee, over the original $100 to $120 purchase price. True, there’s no subscription, but ON1 still costs a modest annual fee, presuming you want the latest features.

Now, I have absolutely no problem with that, and ON1 2019 is a significant improvement.

However, I found that for astrophotography it still isn’t there yet as a complete replacement for Adobe.

But don’t take my word for it. Download the trial copy and test it for yourself.

— Alan, November 22, 2018 / © 2018 Alan Dyer/AmazingSky.com 

 

Banff by Night


Milky Way Reflections at Bow Lake

Three perfect nights in July provided opportunities to capture the night sky at popular sites in Banff National Park.

When the weather forecast in mid-July looked so promising I made an impromptu trip to Banff to shoot nightscapes and time-lapses under unusually clear skies. Clouds are often the norm in the mountains or, increasingly these days, forest fire smoke in late summer.

But from July 15 to 17 the skies could not have been clearer, except for the clouds that rolled in late on my last night, when I was happy to pack up and get some sleep.

Conjunction over the Continental Divide with Train

My first priority was to shoot the marvellous close conjunction of the Moon and Venus on July 15. I did so from the Storm Mountain viewpoint on the Bow Valley Parkway, with a cooperative train also coming through the scene at the right time.

The Milky Way and Mars over Storm Mountain

This was the view later with the Milky Way and Mars over Bow Valley and Storm Mountain.

Bow Lake by Night Panorama

The next night, July 16, was one of the most perfect I had ever seen in the Rockies. Crystal clear skies, calm winds, and great lake reflections made for a picture-perfect night at Bow Lake on the Icefields Parkway. Above is a 360° panorama shot toward the end of the night when the galactic centre of the Milky Way was over Bow Glacier.

Streaks of green airglow arc across the south, while to the north the sky is purple from a faint display of aurora.

Earlier that night the usual auroral arc known as Steve put in an unexpected appearance. It was just a grey band to the eye, but the camera picked up Steve’s usual pink colours. Another photographer from the U.S. who showed up had no idea there was an aurora happening until I pointed it out.

Mars and the Milky Way at Herbert Lake

My last night was at Herbert Lake, a small pond great for capturing reflections of the mountains around Lake Louise, and the Milky Way. Here, brilliant Mars, so photogenic this summer, also reflects in the still waters.

At each site I shot time-lapses, and used those frames to have some fun with star trail stacking, showing the stars turning from east to west and reflected in the lake waters, and with a single still image taken at the end of the sequence layered in to show the untrailed sky and Milky Way.

But I also turned those frames into time-lapse movies, and incorporated them into a new music video, along with some favourite older clips reprocessed for this new video.

Banff by Night (4K) from Alan Dyer on Vimeo.

Enjoy! And do enlarge to full screen. The video is also in 4K resolution.

Clear skies!

— Alan, August 2, 2018 / © 2018 Alan Dyer / AmazingSky.com

 

Moonlight in the Badlands


Stars over Sedimentary Layers

Clear nights and a waxing Moon made for great opportunities to shoot the Badlands under moonlight.

This has not been a great spring. Only now is the last of the snow melting here in Alberta.

But some mild and clear nights this week with the waxing gibbous Moon allowed me to head to the Red Deer River valley near where I live in Alberta for some moonlit nightscapes.

 

Big Dipper over the Badlands

Here’s the Big Dipper high overhead as it is in spring pointing down to Polaris.

I shot this and some other images in this gallery with the new Sony a7III mirrorless camera. A full test of its astrophoto abilities is in the works.

Jupiter Rising over Red Deer River Badlands

This is Jupiter rising, with the Moon lighting the sky, and illuminating the landscape. Moonlight is the same colour as sunlight, just much fainter. So while this might look like a daytime scene, it isn’t.

Venus in Twilight at the Hoodoos

This is Venus setting in the evening twilight at the Hoodoos on Highway 10 near Drumheller. The winter stars are setting into the west, to disappear for a few months.

Venus, Pleiades and Hyades in Twilight

Here’s Venus in closeup, passing between the Hyades and Pleiades star clusters in Taurus, low in the twilight over the scenic Horsethief Canyon area of the Red Deer River.

While Venus is climbing higher into our evening sky this spring, the Pleiades, Hyades and all the winter stars are fast disappearing from view.

We say goodbye to winter, and not a moment too soon!

— Alan, April 28, 2018 / © 2018 Alan Dyer / AmazingSky.com

 

The Beauty of the Milky Way


Beauty of Milky Way Title

I present a new 4-minute music video (in 4K resolution) featuring time-lapses of the Milky Way.

One of the most amazing sights is the Milky Way slowly moving across the sky. From Canada we see the brightest part of the Milky Way, its core region in Sagittarius and Scorpius moving across the souther horizon in summer.

But from the southern hemisphere, the galactic core rises dramatically and climbs directly overhead, providing a jaw-dropping view of our edge-on Galaxy stretching across the sky. It is a sight all stargazers should see.

I shot the time-lapses from Alberta, Canada and from Australia, mostly in 2016 and 2017.

I include a still-image mosaic of the Milky Way from Aquila to Crux shot in Chile in 2011.

Do watch in 4K if you can! And in Full-Screen mode.

Locations include Writing-on-Stone and Police Outpost Provincial Parks, and Banff and Jasper National Parks in Alberta.

In Australia I shot from the Victoria coast and from inland in New South Wales near Coonabarabran, with some scenes from the annual OzSky Star Safari held each April.

I used a SYRP Genie Mini and a Star Adventurer Mini for the panning sequences, and a TimeLapse+ View intervalometer for the day-to-night sequences.

I processed all sequences (some 7500 frames in total) through the software LRTimelapse to smooth transitions and flickering.

Music is by Audiomachine.

Enjoy!

— Alan, January 22, 2018 / © 2018 Alan Dyer / amazingsky.com 

 

The Fast 14s Face-Off


Sigma and Rokinon 14mm on Stars

I put two new fast 14mm lenses to the test: the Sigma 14mm f/1.8 Art vs. the Rokinon 14mm f/2.4 SP. 

Much to the delight of nightscape and astrophotographers everywhere we have a great selection of new and fast wide-angle lenses to pick from.

Introduced in 2017 are two fast ultra-wide 14mm lenses, from Sigma and from Rokinon/Samyang. Both are rectilinear, not fish-eye, lenses.

I tested the Nikon version of the Sigma 14mm f/1.8 Art lens vs. the Canon version of the Rokinon 14mm f/2.4 SP. I used a Nikon D750 and Canon 6D MkII camera.

I also tested the new faster Rokinon SP against the older and still available Rokinon 14mm f/2.8, long a popular lens among nightscape photographers.

The Sigma 14mm is a fully automatic lens with auto focus. It is the latest in their highly regarded Art series of premium lenses. I have their 20mm and 24mm Art lenses and love them.

The Rokinon 14mm SP (also sold under the Samyang brand) is a manual focus lens, but with an AE chip so that it communicates with the camera. Adjusting the aperture is done on the camera, not by turning a manual aperture ring, as is the case with many of Rokinon’s lower cost series of manual lenses. The lens aperture is then recorded in each image’s EXIF metadata, an aid to later processing. It is part of Rokinon’s premium “Special Performance” SP series which includes an 85mm f/1.2 lens.

All units I tested were items purchased from stock, and were not supplied by manufacturers as samples for testing. I own these!


CONCLUSIONS

For those with no time to read the full review, here are the key points:

• The Sigma f/1.8 Art exhibits slightly more off-axis aberrations than the Rokinon 14mm SP, even at the same aperture. But aberrations are very well controlled.

• As its key selling point, the Sigma offers another full stop of aperture over the Rokinon SP (f/1.8 vs. f/2.4), making many types of images much more feasible, such as high-cadence aurora time-lapses and fixed-camera stills and time-lapses of a deeper, richer Milky Way.

• The Sigma also has lower levels of vignetting (darkening of the frame corners) than the Rokinon 14mm SP, even at the same apertures.

• Both the Sigma Art and Rokinon SP lenses showed very sharp star images at the centre of the frame.

• Comparing the new premium Rokinon 14mm SP against the older Rokinon 14mm f/2.8 revealed that the new SP model has reduced off-axis aberrations and lower levels of vignetting than the lower-cost f/2.8 model. However, so it should for double the price or more of the original f/2.8 lens.

• The Rokinon 14mm SP is a great choice for deep-sky imaging where optical quality is paramount. The Sigma 14mm Art’s extra speed will be superb for time-lapse imaging where the f/1.8 aperture provides more freedom to use shorter shutter speeds or lower ISO settings.

Though exhibiting the lowest image quality of the three lenses, the original Rokinon 14mm f/2.8 remains a superb value, at its typical price of $350 to $500. For nightscapers on a budget, it’s an excellent choice.

 


TESTING PROCEDURES

For all these tests I placed the camera and lens on a tracking mount, the Sky-Watcher Star Adventurer Mini shown below. This allowed the camera to follow the sky, preventing any star trailing. Any distortions you see are due to the lens, not sky motion.

Sigma on SAM on Stars
Star Adventurer Mini Tracker (with Sigma 14mm on Nikon D750)

As I stopped down the aperture, I lengthened the exposure time to compensate, so all images were equally well exposed.

In developing the Raw files in Adobe Camera Raw, I applied a standard level of Contrast (25) and Clarity (50) boost, and a modest colour correction to neutralize the background sky colour. I also applied a standard level of noise reduction and sharpening.

However, I did not apply any lens corrections that, if applied, would reduce lateral chromatic aberrations and compensate for lens vignetting.

So what you see here is what the lens produced out of the camera, with no corrections. Keep in mind that the vignetting you see can be largely compensated for in Raw development, with the provisos noted below. But I wanted to show how much vignetting each lens exhibited.


OFF-AXIS ABERRATIONS

Stars are the severest test of any lens. Not test charts, not day shots of city skylines. Stars.

The first concern with any fast lens is how sharp the stars are not only in the centre of the frame, but also across the frame to the corners. Every lens design requires manufacturers to make compromises on what lens aberrations they are going to suppress at the expense of other lens characteristics. You can never have it all!

However, for astrophotography we do look for stars to be as pinpoint as possible to the corners, with little coma and astigmatism splaying stars into seagull and comet shapes. Stars should also not become rainbow-coloured blobs from lateral chromatic aberration.

SIGMA 14mm ART

Sigma 14mm Upper L Corner
Sigma 14mm Art – Upper Left Corner Close-up at 5 Apertures
Sigma 14mm Upper R Corner
Sigma 14mm Art – Upper Right Corner Close-up at 5 Apertures

These images show 200% blowups of the two upper corners of the Sigma 14mm Art lens, each at five apertures, from wide open at f/1.8, then stopped down at 1/3rd stop increments to f/2.8. As you would expect, performance improves as you stop down the lens, though some astigmatism and coma are still present at f/2.8.

But even wide open at f/1.8, off-axis aberrations are very well controlled and minimal. You have to zoom up this much to see them.

There was no detectable lateral chromatic aberration.

Aberrations were also equal at each corner, showing good lens centering and tight assembly tolerances.

ROKINON 14mm SP

Rokinon 14mm Upper L Corner
Rokinon 14mm SP at 3 Apertures
Rokinon 14mm Upper R Corner
Rokinon 14mm SP at 3 Apertures

Similarly, these images show 200% blow-ups of the upper corners of the Rokinon SP, at its three widest apertures: f/2.4, f/2.8 and f/3.2.

Star images look tighter and less aberrated in the Rokinon, even when compared at the same apertures.

But images look better on the left side of the frame than on the right, indicating a slight lens de-centering or variation in lens position or figuring, a flaw noted by other users in testing Rokinon lenses. The difference is not great and takes pixel-peeping to see. Nevertheless, it is there, and may vary from unit to unit. This should not be the case with any “premium” lens.

SIGMA vs. ROKINON

Rokinon vs Sigma (Corner Aberrations)
Rokinon vs. Sigma Corner Aberrations Compared

This image shows both lenses in one frame, at the same apertures, for a more direct comparison. The Rokinon SP is better, but of course, doesn’t go to f/1.8 as does the Sigma.


ON-AXIS ABERRATIONS

We don’t want good performance at the corners if it means sacrificing sharp images at the centre of the frame, where other aberrations such as spherical aberration can take their toll and blur images.

These images compare the two lenses in 200% blow-ups of an area in the Cygnus Milky Way that includes the Coathanger star cluster. Both lenses look equally as sharp.

SIGMA 14mm ART

Sigma 14mm Centre
Sigma 14mm Art – Centre of Frame Close-up

Even when wide open at f/1.8 the Sigma Art shows very sharp star images, with little improvement when stopped down. Excellent!

ROKINON 14mm SP

Rokinon 14mm Centre
Rokinon 14mm SP – Centre of Frame Close-up

The same can be said for the Rokinon SP. It performs very well when wide open at f/2.4, with star images as sharp as when stopped down 2/3rds of an f-stop to f/3.2

SIGMA vs. ROKINON

Rokinon vs Sigma (Centre Aberrations)
Sigma vs. Rokinon Centre Sharpness Compared

This image shows both lenses in one frame, but with the Sigma wide open at f/1.8 and stopped down to f/2.8, vs. the Rokinon wide open at f/2.4 and stopped to f/2.8. All look superb.


VIGNETTING

The bane of wide-angle lenses is the light fall-off that is inevitable as lens focal lengths decrease. We’d like this vignetting to be minimal. While it can be corrected for later when developing the Raw files, doing so can raise the visibility of noise and discolouration, such as magenta casts. The less vignetting we have to deal with the better.

As with off-axis aberrations, vignetting decreases as lenses are stopped down. Images become more uniformly illuminated across the frame, with less of a “hot spot” in the centre.

SIGMA 14mm ART

Sigma 14mm Vignetting (5 Apertures)
Sigma 14mm Art – Vignetting Compared at 5 Apertures

This set compares the left edge of the frame in the Sigma SP at five apertures, from f/1.8 to f/2.8. You can see how the image gets brighter and more uniform as the lens is stopped down. (The inset image at upper right show what part of the frame I am zooming into.)

ROKINON 14mm SP

Rokinon 14mm Vignetting (3 Apertures)
Rokinon 14mm SP – Vignetting Compared at 3 Apertures

This similar set compares the frame’s left edge in the Rokinon SP at its three widest apertures, from f/2.4 to f/3.2. Again, vignetting improves but is still present at f/3.2.

SIGMA vs. ROKINON

Rokinon vs Sigma Vignetting
Rokinon vs. Sigma – Vignetting Compared

This compares both lenses at similar apertures side by side for a direct comparison. The Sigma is better than the Rokinon with a much more uniform illumination across the frame.

Sigma 14mm Vignetting at f1.8
Sigma 14mm Art – Vignetting at f/1.8 Maximum Aperture
Rokinon 14mm Vignetting at f2.4
Rokinon 14mm SP – Vignetting at f/2.4 Maximum Aperture

In these two images, above, of the entire frame at their respectively widest apertures, I’d say the Sigma exhibits less vignetting than the Rokinon, even when wide open at f/1.8. The cost for this performance, other than in dollars, is that the Sigma is a large, heavy lens with a massive front lens element.


ROKINON 14mm f/2.4 SP vs. ROKINON 14mm f/2.8 Standard

Even the Rokinon 14mm SP, though a manual lens, carries a premium price, at $800 to $1000 U.S., depending on the lens mount.

Samyang 14mm Lens
The 14mm Rokinon/Samyang f/2.8 Lens

For those looking for a low-cost, ultra-wide lens, the original Rokinon/Samyang 14mm f/2.8 (shown above) is still available and popular. It is a fully manual lens, though versions are available with a AE chip to communicate lens aperture information to the camera.

I happily used this f/2.8 lens for several years. Before I sold it earlier in 2017 (before I acquired the Sigma 14mm), I tested it against Rokinon’s premium SP version.

The older f/2.8 lens exhibited worse off-axis and on-axis aberrations and vignetting than the SP, even with the SP lens set to the same f/2.8 aperture. But image quality of the original lens is still very good, and the price is attractive, at half the price or less, than the 14mm SP Rokinon.

TWO 14mm ROKINONS: OFF-AXIS ABERRATIONS

14mm Rokinons Aberrations (Upper L Corner)
Two Rokinons (Older “Standard” vs. new SP) – Upper Left Corner Close-up
14mm Rokinons Aberrations (Upper R Corner)
Two Rokinons (Older “Standard” vs. new SP) – Upper Right Corner Close-up

Here, in closeups of the upper corners, I show the difference between the two Rokinons, the older standard lens on the left, and the new SP on the right.

The SP, as it should, shows lower aberrations and tighter star images, though with the improvement most marked on the left corner; not so much on the right corner. The original f/2.8 lens holds its own quite well.

TWO 14mm ROKINONS: ON-AXIS ABERRATIONS

14mm Rokinons Aberrations (Centre)
Two Rokinons (Older “Standard” vs. new SP) – Centre of Frame Close-up

At the centre of the frame, the difference is more apparent, with the SP lens exhibiting sharper star images than the old 14mm with its generally softer, larger star images. The latter likely has more spherical aberration.

TWO 14mm ROKINONS: VIGNETTING

14mm Rokinons Vignetting
Two Rokinons (Older “Standard” vs. new SP) – Vignetting Compared

The new SP lens clearly has the advantage here, with less vignetting and brighter corners even when wide open at f/2.4 than the older lens does at its widest aperture of f/2.8. This is another reason to go for the new SP if image quality is paramount


PRICES

The new Sigma 14mm Art lens is costly, at $1600 U.S., though with a price commensurate with its focal length and aperture. Other premium lenses in this focal length range, either prime or zoom, from Nikon and Canon sell for much more, and have only an f/2.8 maximum aperture. So in that sense, the Sigma Art is a bargain.

The new Rokinon 14mm SP sells for $800 to $1000, still a premium price for a manual focus lens. But its optical quality competes with the best.

The older Rokinon 14mm f/2.8 is a fantastic value at $350 to $500, depending on lens mount and AE chip. For anyone getting into nightscape and Milky Way photography, it is a great choice.


RECOMMENDATIONS

With such a huge range in price, what should you buy?

A 14mm is a superb lens for nightscape shooting – for sky-filling auroras, for panoramas along the Milky Way, or of the entire sky. But the lens needs to be fast. All three lenses on offer here satisfy that requirement.

Sigma 14mm & Rokinon 14mm SP (Front)
Sigma 14mm Art (left) and Rokinon 14mm SP (right)

SIGMA 14mm f/1.8 ART

If you want sheer speed, this is the lens. It offers a full stop gain over the already fast Rokinon f/2.5, allowing exposures to be half the length, or shooting at half the ISO speed for less noise.

Its fast speed comes into its own for rapid cadence aurora time-lapses, to freeze auroral motion as much as possible in exposures as short as 1 to 2 seconds at a high ISO. The fast speed might also make real-time movies of the aurora possible on cameras sensitive and noiseless enough to allow video shooting at ISO 25,000 and higher, such as the Sony a7s models.

The Sigma’s fast speed also allows grabbing rich images of the Milky Way in exposures short enough to avoid star trailing, either in still images or in time-lapses of the Milky Way in motion.

While the Sigma does exhibit some edge aberrations, they are very well controlled (much less than I see with some 24mm and 35mm lenses I have) and are a reasonable tradeoff for the speed and low level of vignetting, which results in less noisy corners.

Photographers obsess over corner aberrations when, for fixed-camera nightscape shooting, a low level of vignetting is probably more critical. Correcting excessive vignetting introduces noise, while the corner aberrations may well be masked by star trailing. Only in tracked images do corner aberrations become more visible, as in the test images here.

I’d suggest the Sigma is the best choice for nightscape and time-lapse shooting, with its speed allowing for kinds of shots not possible otherwise.

The Sigma also appears to be the best coated of all the lenses, as you can see in the reflections in the lenses in the opening image, and below. However, I did not test the lenses for flares and ghosting.

As a footnote, none of the lenses allow front-mounted filters, and none have filter drawers.

ROKINON 14mm f/2.4 SP

For less money you get excellent optical quality, though with perhaps some worrisome variation in how well the lens elements are figured or assembled, as evidenced by the inconsistent level of aberration from corner to corner.

Nevertheless, stars are tight on- and off-axis, and vignetting is quite low, for corners that will be less noisy when the shadows are recovered in processing.

I’d suggest the Rokinon SP is a great choice if tracked deep-sky images are your prime interest, where off-axis performance is most visible. However, the SP’s inconsistent aberrations from corner to corner are evidence of lower manufacturing tolerances than Sigma’s, so your unit may not perform like mine.

For nightscape work, the SP’s f/2.4 aperture might seem a minor gain over Rokinon’s lower-cost f/2.8 lens. But it is 1/3 of an f-stop. That means, for example, untracked Milky Way exposures could be 30 seconds instead of 40 seconds, short enough to avoid obvious star trailing. At night, every fraction of an f-stop gain is welcome and significant.

ROKINON 14mm f/2.8 Standard

You might never see the difference in quality between this lens and its premium SP brother in images intended for time-lapse movies, even at 4K resolution.

But those intending to do long-exposure deep-sky imaging, as these test images are, will want the sharpest stars possible across the frame. In which case, consider the 14mm SP.

But if price is a prime consideration, the original f/2.8 Rokinon is a fine choice. You’ll need to apply a fair amount of lens correction in processing, but the lens exists in the Camera Raw/Lightroom database, so correction is just a click away.


Sigma and Rokinon 14mm on Stars

That was a lengthy report, I know! But there’s no point in providing recommendations without the evidence to back them up.

All images, other than the opening “beauty shot,” can be clicked/tapped on to download a full-resolution original JPG for closer inspection.

As I’ve just received the Sigma Art lens I’ve not had a chance to shoot any “real” nightscape images with it yet, just these test shots. But for a real life deep-sky image of the Milky Way shot with the Rokinon SP, see this image from Australia. https://flic.kr/p/SSQm7G

I hope you found the test of value in helping you choose a lens.

Clear skies!

— Alan, September 22, 2017 / © 2017 Alan Dyer / amazingsky.com

 

A Starry Night in the Badlands


Winter Milky Way Arch and Zodiacal Light

In a winter of cloud, the skies cleared for a magical night in the Alberta Badlands.

Two weeks ago, on February 28, I took advantage of a rare and pristine night to head to one of my favourite spots in Dinosaur Provincial Park, to shoot nightscapes of the winter sky over the Badlands.

A spate of warm weather had melted most of the snow, so the landscape doesn’t look too wintery. But the stars definitely belong to winter in the Northern Hemisphere.

The main image above shows the winter Milky Way arching across the sky from southeast (at left) to northwest (at right). The tower of light in the west is the Zodiacal Light, caused by sunlight reflecting off dust particles in the inner solar system. It is an interplanetary, not atmospheric, effect.

Winter Sky Panorama at Dinosaur Park (Fish-Eye View)
This is a stitch of 6 segments with the 12mm Rokinon lens at f/2.8 for 30 seconds each, with the Nikon D750 at ISO 6400, mounted portrait. Stitched with PTGui.

Above, this 360° version of the scene records the entire sky, with the winter Milky Way from horizon to horizon. With a little averted imagination you can also trace the Zodiacal Light from west (right) over to the eastern sky (left), where it brightens in the diffuse glow of the Gegenschein, where dust opposite the Sun in the outer solar system reflects light back to us.

Winter Sky Panorama at Dinosaur Park (with Labels)
This is a stitch of 6 segments taken with the 12mm full-fame fish-eye Rokinon lens at f/2.8, all 30-second exposures with the Nikon D750 at ISO 6400. The camera was aimed portrait with the segments at 60° spacings. Stitched with PTGui using equirectangular projection with the zeith pulled down slightly.

A rectangular version of the panorama wraps the sky around from east (left), with Leo rising, to northeast (right), with the Big Dipper standing on its handle. I’ve added the labels in Photoshop of course.

Winter Stars over Dinosaur Park
This is a stack of 8 x 30-second exposures for the ground, mean combined to smooth noise, plus one 30-second exposure for the sky. All at f/2.2 with the Sigma 20mm Art lens and Nikon D750 at ISO 6400.

Here, in a single-frame shot, Orion is at centre, Canis Major (with Sirius) is below left, and Taurus (with Aldebaran) is at upper right. The Milky Way runs down to the south. The clusters M35, M41, M46 and M47 are visible as diffuse spots, as is the Orion Nebula, M42, below Orion’s Belt.

Evening Zodiacal Light at Dinosaur Park
The late winter evening Zodiacal Light, from at Dinosaur Provincial Park, Alberta, February 28, 2017. This is a stack of 7 x 30-second exposures for the ground, mean combined for lower noise, plus one 30-second exposure for the sky, all at f/2 with the 20mm Sigma Art lens, and Nikon D750 at ISO 6400.

This is certainly my best shot of the evening Zodiacal Light from my area in Alberta. It is obvious at this time of year on moonless nights, but requires a site with little urban skyglow to the west.

It is best visible in the evening from northern latitudes in late winter and spring.

Here, Venus is just setting above the badlands landscape. The Andromeda Galaxy is at right, the Pleiades at left. The Milky Way runs across the frame at top.

There is a common belief among nightscape photographers that the Milky Way can be seen only in summer. Not so.

What they mean is that the brightest part of the Milky Way, the galactic centre, is best seen in summer. But the Milky Way can be seen in all seasons, with the exception of spring when it is largely absent from the early evening sky, but rises late at night.

— Alan, March 14, 2017 / © 2017 Alan Dyer / AmazingSky.com 

 

Jasper by Starlight


Taurus Rising over Mount Kerkeslin

The annual Dark Sky Festival in Jasper National Park ended with the best finale – dark skies, on a beautiful star-filled night. 

On Saturday night, October 22, I left the final set of science talks in the Big Tent at the heart of the Festival and headed out down the Icefields Parkway for a night of shooting Jasper by starlight.

The lead image is of the winter stars, including the Pleiades, rising above Mt. Kerkeslin at Athabasca Falls.

Pleiades and Taurus over Athabasca Falls
The Pleiades star cluster and the other stars of Taurus rising above Mount Kerkeslin at Athabasca Falls, in Jasper National Park, Alberta, October 22, 2016. The sky is brightening with the rising waning Moon off frame at left. Some cloud adds star glows and hazy patches to the sky. This is a stack of 15 exposures, mean combined to smooth noise, for the ground and one exposure for the sky. All are 25 seconds at f/2 with the Sigma 20mm Art lens and Nikon D750 at ISO 6400.

I shot the image above moments later, from the usual viewpoint overlooking the Falls, reduced to a trickle in late autumn. Illumination is solely by starlight – no artificial and glaring light painting here.

Perseus and Cassiopeia over Mt Kerkeslin
The autumn constellations of Perseus, Cassiopeia and Andromeda over Mount Kerkeslin at the Athabasca River Viewpoint on the Icefields Parkway, in Jasper National Park, Alberta. The Andromeda Galaxy is at upper right. The Pleiades are just clearing the mountain top at lower right. Thin clouds add the natural glows around the stars. Illumination is from starlight. This is a stack of 8 exposures, mean combined to smooth noise, for the ground and one exposure for the sky, all 25 seconds at f/2 with the Sigma 20mm lens and Nikon D750 at ISO 6400.

Earlier in the night, I stopped at the Athabasca River Viewpoint and shot the autumn stars of Cassiopeia, Andromeda, and Perseus above Mt. Kerkeslin. The Pleiades are just appearing above the mountain ridge.

Stars over Athabasca River
The autumn stars of the watery constellations of Capricornus, Aquarius, Piscis Austrinus, and Cetus over the Athabasca River and the peaks of the Continental Divide, from the Athabasca River Viewpoint (the “Goats and Glaciers” viewpoint) on the Icefields Parkway, Jasper National Park, Alberta. Thin cloud provides the natural glows around the stars. This is a stack of 8 exposures for the ground, mean combined to smooth noise, and one exposure for the sky, all 25 seconds at f/2 with the Sigma 20mm Art lens, and Nikon D750 at ISO 6400.

From that viewpoint I shot a scene looking south over the river and with the stars of Capricornus and Aquarius above the Divide.

Milky Way over Athabasca Pass
The Milky Way over the region of Athabasca Pass, as seen from the highway viewpoint on the Icefields Parkway, in Jasper National Park, Alberta, Oct 22, 2016. The Milky Way here is the section through Aquila, with Altair at top and Mars bright above the peaks of the Continental Divide. This is a stack of 8 exposures, mean combined to smooth noise, for the ground and one exposure for the sky, all 25 seconds at f/2 with the Sigma 20mm lens, and Nkion D750 at ISO 6400.

At the start of the night I stopped at the viewpoint for Athabasca Pass far in the distance. The summer Milky Way was setting over the pass. This historic pass was used by David Thompson in the late 1700s and early 1800s as his route into B.C. to extend the fur trade across the Divide. Thompson writes in his Journal about one particularly clear night on the pass:

“My men were not at their ease, yet when night came they admired the brilliancy of the Stars, and as one of them said, he thought he could almost touch them with his hand.”

The night ended with a display of Northern Lights over the Athabasca River. What a superb night under the stars in Jasper!

Aurora over Athabasca River
The Northern Lights over the Athabasca River in Jasper National Park, Alberta, Canada, on October 22/23 at about 1:30 am. I shot this from an access point to the Athabasca River by the bridge on Highway 93 on the Icefields Parkway. Pyramid Mountain is at left near the town of Jasper. Vega is the bright star at left; the Big Dipper is at right. The image is a stack of 10 exposures for the ground, mean combined to smooth noise and to smooth the water, and one exposure for the sky and aurora. All 15 seconds at ISO 1600 at f2 with the Sigma 20mm lens and Nikon D750.

As a finale, here’s a music video collecting together still images and time-lapse movies shot this night, and on two other nights during the Dark Sky Festival, including at the big Lake Annette “Beyond the Stars” star party I spoke at.

Enjoy!

As usual, enlarge to full screen and go to HD for the best view.

Thanks!

— Alan, October 24, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

The Moving Stars of the Southern Hemisphere


Southern Sky Star Trails - OzSky Looking South

Nothing amazes even the most inveterate skywatcher more than traveling to another hemisphere and seeing sky move. It moves the wrong way!

Whether you are from the southern hemisphere traveling north, or as I do, travel south from the Northern Hemisphere, watching how the sky moves can be disorienting.

Here I present a video montage of time-lapses shot last April in Australia, at the annual OzSky Star Party near Coonabarabran in New South Wales.

Select HD and Enlarge button to view at full screen at best quality.

You’ll see the sky set in the west but traveling in arcs from right to left, then in the next clip, rise in the east, again moving from right to left. That’s the wrong angle for us northerners.

Looking north you see the seasonal constellations, the ones that rise and set over a night and that change with the seasons. In this case, the night starts with Orion (upside-down!) to the north but setting over in the west, followed by Leo and bright Jupiter. The sky is moving from east to west, but that’s from right to left here. The austral Sun does the same thing by day.

Looking south, we see the circumpolar constellations, the ones that circle the South Celestial Pole. Only there’s no bright “South Star” to mark the pole.

The sky, including the two Magellanic Clouds (satellite galaxies to the Milky Way) and the spectacular Milky Way itself, turns around the blank pole, moving clockwise – the opposite direction to what we see up north.

I shot the sequences over four nights in early April, as several dozen stargazers from around the world revelled under the southern stars, using an array of impressive telescopes supplied by the Three Rivers Foundation, Australia, for us to explore the southern sky.

I’ll be back next year!

– Alan, August 19, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

Capturing the Quadrantids


Quadrantid Meteor Shower Composite

The Quadrantid meteors streaked out of the northern sky on a fine winter’s night.

The temperature was mild and skies clear in the early evening for the annual Quadrantid meteor shower. This is a prolific but short-lived shower with a brief peak. The cold and low altitude of its radiant point keeps this shower from becoming better known.

This was the first year I can recall shooting it. I had some success during a 2-hour shoot on January 3, from 9 to 11 pm MST.

The result above is a stack of 14 images, the best out of 600 shot that recorded meteors. The ground and sky comes from one image with the best Quad of the night, and the other meteor images were masked and layered into that image, with no attempt to align their paths with the moving radiant point.

However, over the 2 hours, the radiant point low in the north would not have moved too much, as it rose higher into the northern sky.

Most of the meteors here are Quads, but the very bright bolide at left, while it looks like it is coming from the radiant, it is actually streaking toward the radiant, and is not a Quadrantid. But oh so close! I left it in the composite for the sake of the nice composition!

Light clouds moving in added the natural star glows around the Big Dipper stars.

All frames were 10 seconds at f/2 with the 24mm lens and Nikon D750 at ISO 3200.

— Alan, January 4, 2016 / © 2016 Alan Dyer / www.amazingsky.com 

Astrophotography Video Tutorials – Free!


 

Video Tutorial FB PR ImageLearn the basics of shooting nightscape and time-lapse images with my three new video tutorials.

In these comprehensive and free tutorials I take you from “field to final,” to illustrate tips and techniques for shooting the sky at night.

At sites in southern Alberta I first explain how to shoot the images. Then back at the computer I step you through how to process non-destructively, using images I shot that night in the field.


 

Tutorial #1 – The Northern Lights

This 24-minute tutorial takes you from a shoot at a lakeside site in southern Alberta on a night with a fine aurora display, through to the steps to processing a still image and assembling a time-lapse movie.


 

Tutorial #2 – Moonlit Nightscapes

This 28-minute tutorial takes you from a shoot at Waterton Lakes National Park on a bright moonlit night, to the steps for processing nightscapes using Camera Raw and Photoshop, with smart filters, adjustment layers and masks.


 

Tutorial #3 – Star Trails

This 35-minute tutorial takes you from a shoot at summer solstice at Dinosaur Provincial Park, then through the steps for stacking star trail stills and assembling star trail time-lapse movies, using specialized programs such as StarStaX and the Advanced Stacker Plus actions for Photoshop.

 

As always, enlarge to full screen for the HD versions. These are also viewable at my Vimeo channel.  

Or they can be viewed on my YouTube channel

Thanks for watching!

And for much more information about shooting and processing nightscapes and time-lapse movies, check out my 400-page multimedia eBook, linked below.

— Alan, November 21, 2015 / © 2015 Alan Dyer / www.amazingsky.com/tutorials.html

 

A Super Eclipse of the Moon


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. This was the night of a total lunar eclipse, which was in progress in its initial partial phase as the Moon rose this night. The blue band on the horizon containing the Moon is the shadow of Earth on our atmosphere, while the dark bite taken out of the lunar disk is the shadow of Earth on the Moon. The pink band above is the Belt of Venus. This is a two-image panorama stitched to extend the scene vertically to take in more sky and ground than one frame could accommodate. Both shot with the 200mm lens and 1.4x extender, on the Canon 5DMkII.

I could not have asked for a more perfect night for a lunar eclipse. It doesn’t get any better!

On Sunday, September 27, the Moon was eclipsed for the fourth time in two years, the last in a “tetrad” of total lunar eclipses that we’ve enjoyed at six-month intervals since April 2014. This was the best one by far.

The Full Moon rising in partial eclipse on the night of September 27, 2015, night of a total eclipse that began with the partial phase in progress at moonrise from my location. The pink Belt of Venus colours the sky at top. The Moon sits in the blue shadow of the Earth, which also partly obscures the disk of the Moon. I shot this from Writing-on-Stone Provincial Park, Alberta. This is through the TMB 92mm refractor for a focal length of 550mm using the Canon 60Da at ISO 400 for 1/250 second.
This is through the TMB 92mm refractor for a focal length of 500mm using the Canon 60Da at ISO 400 for 1/250 second.

The timing was perfect for me in Alberta, with the Moon rising in partial eclipse (above), itself a fine photogenic site.

In the top image you can see the rising Moon embedded in the blue band of Earth’s shadow on our atmosphere, and also entering Earth’s shadow on its lunar disk. This was a perfect alignment, as lunar eclipses must be.

For my earthly location I drove south to near the Montana border, to a favourite location, Writing-on-Stone Provincial Park, to view the eclipse over the sandstone formations of the Milk River.

The image below shows a screen shot of my site plan and viewing angles using The Photographer’s Ephemeris app.

IMG_2515

More importantly, weather forecasts for the area called for perfectly clear skies, a relief from the clouds forecast – and which did materialize – at home to the north, and would have been a frustration to say the least. Better to drive 3 hours!

This was the second lunar eclipse I viewed from Writing-on-Stone, having chased clear skies to here in the middle of the night for the October 8, 2014 eclipse.

Me, in a selfie, observing a total eclipse of the Moon with binoculars on September 27, 2015, from Writing-on-Stone Provincial Park, Alberta. I had three cameras set up to shoot the eclipse and a fourth to shoot the scene like this. The night was perfect for the eclipse. The Moon is in totality here, with the stars and Moon trailed slightly from the long exposure.

I shot with three cameras: one doing a time-lapse through the telescope, one doing a wide-angle time-lapse of the Moon rising, and the third for long-exposure tracked shots during totality, of the Moon and Milky Way.

The Moon in total eclipse on September 27, 2015 – the “supermoon” eclipse – shining red over the Milk River and sandstone formations at Writing-on-Stone Provincial Park in southern Alberta, with the Milky Way in full view in the sky darkened by the lunar eclipse. The Sweetgrass Hills of Montana are to the south. The centre of the Milky Way is at far right. The Andromeda Galaxy is at upper left. The Moon was in Pisces below the Square of Pegasus. It was a perfectly clear night, ideal conditions for shooting the eclipse and stars. This is a stack of 5 x 2-minute tracked exposures for the sky and 5 x 4-minute untracked exposures for the ground to smooth noise. The Moon itself comes from a short 30-second exposure to avoid overexposing the lunar disk. Illumination of the ground is from starlight. All exposures with the 15mm lens at f/2.8 and Canon 5D MkII at ISO 1600. The camera was on the iOptron Sky-Tracker.
This is a stack of 5 x 2-minute tracked exposures for the sky and 5 x 4-minute untracked exposures for the ground to smooth noise. The Moon itself comes from a short 30-second exposure to avoid overexposing the lunar disk. Illumination of the ground is from starlight. All exposures with the 15mm lens at f/2.8 and Canon 5D MkII at ISO 1600. The camera was on the iOptron Sky-Tracker.

That image is above. It shows the eclipsed Moon at left, with the Milky Way at right, over the Milk River valley and with the Sweetgrass Hills in the distance.

The sky was dark only during the time of totality. As the Moon emerged from Earth’s shadow the sky and landscape lit up again, a wonderful feature of lunar eclipses.

While in the above shot I did layer in a short exposure of the eclipsed Moon into the long exposure of the sky, it is still to accurate scale, unlike many dubious eclipse images I see where giant moons have been pasted into photos, sometimes at least in the right place, but often not.

Lunar eclipses bring out the worst in Photoshop techniques.

The total eclipse of the Moon of September 27, 2015, in closeup through a telescope, at mid-totality with the Moon at its darkest and deepest into the umbral shadow, in a long exposure to bring out the stars surrounding the dark red moon. This was also the Harvest Moon for 2015 and was the perigee Full Moon, the closest Full Moon of 2015. This is a single exposure taken through the TMB 92mm refractor at f/5.5 for 500 mm focal length using the Canon 60Da at ISO 400 for 8 seconds, the longest I shot during totality. The telescope was on the SkyWatcher HEQ5 mount tracking at the lunar rate.
This is a single exposure taken through the TMB 92mm refractor at f/5.5 for 500 mm focal length using the Canon 60Da at ISO 400 for 8 seconds, the longest I shot during totality. The telescope was on the SkyWatcher HEQ5 mount tracking at the lunar rate.

Above is a single closeup image taken through the telescope at mid-totality. I exposed for 8 seconds to bring out the colours of the shadow and the background stars, as faint as they were with the Moon in star-poor Pisces.

I shot a couple of thousand frames and processing of those into time-lapses will take a while longer, in particular registering and aligning the 700 I shot at 15-second intervals through the telescope. They show the Moon entering, passing through, then exiting the umbra, while it moves against the background stars.

Me celebrating a successful total eclipse of the Moon during the final partial phases, observed and shot from Writing-on-Stone Provincial Park, Alberta, on September 27, 2015. I shot with 3 cameras, with a 4th to record the scene. Two of the cameras at centre are still shooting time-lapses of final partial phases. The camera at right was used to take long tracked exposures of the Milky Way during totality. The telescope at left was used just to look!

So I was a happy eclipse chaser! I managed to see all four of the lunar eclipses in the current tetrad, two from Alberta, one from Australia, and one from Monument Valley.

With the latest success, I’ve had my fill of lunar eclipses for a while. Good thing, as the next one is not until January 31, 2018, before dawn in the dead of winter.

With the mild night, great setting, and crystal clear skies, this “supermoon” eclipse could not have been better. It was a super eclipse.

– Alan, September 29, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Canon vs. Nikon for Astrophotography


Canon and Nikon Cameras

I’ve been an avowed Canon DSLR user for a decade. I may be ready to switch!

[NOTE: This review dates from 2015. Tests done today with current models would certainly differ. Canon’s EOS R mirrorless series, for example, offer much better ISO Invariancy performance but lack the “dark frame buffer” advantage of Canon DSLRs. And indeed, I have used the Nikon D750 a lot since 2015. But I did not give up my Canons!]

Here, in a technical blog, I present my tests of two leading contenders for the best DSLR camera for nightscape and astronomical photography: the Canon 6D vs. the Nikon D750. Which is better?

To answer, I subjected both to side-by-side outdoor tests, using exposures you’ll actually use in the field for typical nightscapes and for deep-sky images.

Both cameras are stock, off-the-shelf models. They have not had their filters modified for astronomy use. Both are 20- to 24-megapixel, full-frame cameras, roughly competitive in price ($1,900 to $2,300).

For images shot through lenses, I used the Canon L-Series 24mm on the Canon 6D, and the Sigma 24mm Art lens on the Nikon D750.

The bottom line: Both are great cameras, with the Nikon D750 having the edge for nightscape work, and the Canon 6D the edge for deep-sky exposures.

NOTE: Click on the test images for higher-resolution versions for closer inspection. All images and text © 2015 Alan Dyer and may not be reproduced without my permission.


TEST #1 — Noise

The 24.3-megapixel Nikon D750 has 5.9-micron pixels, while the 20.2-megapixel Canon 6D has slightly larger 6.5-micron pixels which, in theory, should lead to lower noise for the Canon. How do they compare in practice?

The scene used to test for noise (here with the Nikon images) showing the development settings applied to both the Nikon and Canon sets. NO noise reduction (colour or lunminance) was applied to any of the images, but Exposure, Shadows, Contrast and Clarity were boosted, and Highlights reduced.
The scene used to test for noise (here with the Nikon images) showing the development settings applied to both the Nikon and Canon sets. NO noise reduction (colour or lunminance) was applied to any of the images, but Exposure, Shadows, Contrast and Clarity were boosted, and Highlights reduced.

I shot a moonlit nightscape scene (above) at five ISO settings, from 800 to 12800, at increasingly shorter exposures to yield identically exposed frames. I processed each frame as shown above, with boosts to shadows, clarity, and contrast typical for nightscapes. However, I applied no noise reduction (either luminance or color) in processing. Nor did I take and apply dark frames.

Noise - Canon

Noise - Nikon

The blowups of a small section of the frame (outlined in the box in the upper right of the Photoshop screen) show very similar levels of luminance noise. The Canon shows slightly more color noise, in particular more magenta pixels in the shadows at high ISOs. Its larger pixels didn’t provide the expected noise benefit.


TEST #2 — Resolution

Much has been written about the merits of Canon vs. Nikon re: the most rigorous of tests, resolving stars down at the pixel level.

I shot the images below of the Andromeda Galaxy the same night through a 92mm aperture apo refractor. They have had minimal but equal levels of processing applied. At this level of inspection the cameras look identical.

M31 (Canon 6D)

M31 (Nikon D750)

But what if we zoom in?

For many years Nikon DSLRs had a reputation for not being a suitable for stellar photography because of a built-in noise smoothing that affected even Raw files, eliminating tiny stars along with noise. Raw files weren’t raw. Owners worked around this by turning on Long Exposure Noise Reduction, then when LENR kicked in after an exposure, they would manually turn off the camera power.

This so-called “Mode 3” operation yielded a raw frame without the noise smoothing applied. Clearly, this clumsy workaround made it impossible to automate the acquisition of raw image sequences with Nikons.

Are Nikons still handicapped? In examining deep-sky images at the pixel-peeping level (below), I saw absolutely no difference in resolution or the ability to record tiny and faint stars. With its 4-megapixel advantage the Nikon should resolve finer details and smaller stars, but in practice I saw little difference.

Closeup of telescope view of Andromeda Galaxy with Canon 6D 4 minute exposure at ISO 800 No noise reduction applied in processing
Closeup of telescope view of Andromeda Galaxy with Canon 6D
4 minute exposure at ISO 800
No noise reduction applied in processing
Closeup of telescope view of Andromeda Galaxy with Nikon D750 4 minute exposure at ISO 800 No noise reduction applied in processing
Closeup of telescope view of Andromeda Galaxy with Nikon D750
4 minute exposure at ISO 800
No noise reduction applied in processing

On the other hand I saw no evidence for Nikon’s “star eater” reputation. I think it is time to lay this bugbear of Nikons to rest. The Nikon D750 proved to be just as sharp as the Canon 6D.

Note that in the closeups above, the red area marks a highlight (the galaxy core) that is overexposed and clipped. Nikon DSLRs also have a reputation for having sensors with a larger dynamic range than Canon, allowing better recording of highlights before clipping sets in.

However, in practice I saw very little difference in dynamic range between the two cameras. Both clipped at the same points and to the same degree.


TEST #3 — Mirror Box Shadowing

An issue little known outside of astrophotography is that a DSLR’s deeply-inset sensor can be shadowed by the upraised mirror and sides of the mirror box. Less light falls on the edges of the sensor.

The vignetting effect is noticeable only when we boost the contrast to the high degree demanded by deep-sky images, and when shooting through fast telescope systems.

Here I show the vignetting of the Canon and Nikon when shooting through my 92mm refractor at f/4.5.

The circular corner vignetting visible in the images below is from the field flattener/reducer I employed on the telescope. It can be compensated for by using Lens Correction in Adobe Camera Raw, or eliminated by taking flat fields.

Demonstrating the level of vignetting and mirror-box shadowing with the Canon 6D on a TMB 92mm apo refractor with a 0,85x field flattener/reducer lens
Demonstrating the level of vignetting and mirror-box shadowing with the Canon 6D on a TMB 92mm apo refractor with a 0.85x field flattener/reducer lens
Demonstrating the level of vignetting and mirror-box shadowing with the Nikon D750 on a TMB 92mm apo refractor with a 0,85x field flattener/reducer lens
Demonstrating the level of vignetting and mirror-box shadowing with the Nikon D750 on a TMB 92mm apo refractor with a 0.85x field flattener/reducer lens

The dark edge at the bottom of the frame is from shadowing by the upraised mirror. It can be eliminated only by taking flat fields, or reduced by using masked brightness adjustments in processing.

Both cameras showed similar levels of vignetting, with the Canon perhaps having the slight edge.


TEST #4 — ISO Invariancy

So far the Nikon D750 and Canon 6D are coming up fairly equal in performance. But not here. This is where the Nikon outperforms the Canon by quite a wide margin.

Sony sensors (used in Sony cameras and also used by Nikon) have a reputation for being “ISO Invariant.”

What does that mean?

A typical Milky Way nightscape with the Nikon D750 and Sigma 24mm Art lens. With no Moon, shot at very high ISO of 6400 and wide aperture of f/1.4 to show image quality under these demanding shooting circumstances. Lens correction and basic development setttings applied.
A typical Milky Way nightscape with the Nikon D750 and Sigma 24mm Art lens.
With no Moon, shot at very high ISO of 6400 and wide aperture of f/1.4 to show image quality under these demanding shooting circumstances.
Lens correction and basic development setttings applied.
A typical Milky Way nightscape with the Canon 6D and Canon 24mm L lens (original model). With no Moon, shot at very high ISO of 6400 and wide aperture of f/1.4 to show image quality under these demanding shooting circumstances. Lens correction and basic development setttings applied.
A typical Milky Way nightscape with the Canon 6D and Canon 24mm L lens (original model).
With no Moon, shot at very high ISO of 6400 and wide aperture of f/1.4 to show image quality under these demanding shooting circumstances.
Lens correction and basic development setttings applied.

In the examples above, the correct exposure for the starlit scene was 15 seconds at f/1.4 at ISO 6400. See how the two cameras rendered the scene? Very similar, albeit with the Canon showing more noise and discoloration in the dark frame corners.

What if we shoot at the same 15 seconds at f/1.4 … but at ISO 3200, 1600, 800, and 400? These are now 1-, 2-, 3-, and 4-stops underexposed, respectively.

Then we boost the Exposure setting of the underexposed Raw files later in processing, by 1, 2, 3 or 4 f-stops. What do we see?

Nikon D750 - Comparing ISO Invariancy from ISO 6400 to 400 (Nightscape)
Nikon D750 – Comparing ISO Invariancy from ISO 6400 to 400 (Nightscape)

With the Nikon (above) we see images that look nearly identical for noise to what we got with the properly exposed ISO 6400 original. It really didn’t matter what ISO speed the image was shot at – we can turn it into any ISO we want later with little penalty.

Canon 6D - Comparing ISO Invariancy from ISO 6400 to 400 (Nightscape)
Canon 6D – Comparing ISO Invariancy from ISO 6400 to 400 (Nightscape)

With the Canon (above) we get images with grossly worse noise in the shadows and with ugly magenta discoloration. Canons cannot be underexposed. You must use as high an ISO as needed for the correct exposure.

This “ISO Invariant” advantage of Nikon over Canon is especially noticeable in nightscapes scenes lit only by starlight, as above. The Canon turns ugly purple at -3EV underexposure, and loses all detail and contrast at -4EV underexposure.

For nightscape imaging this is an important consideration. We are limited in exposure time and aperture, and so are often working at the ragged edge of exposure. Dark areas of a scene are often underexposed and prone to noise. With the Nikon D750 these areas may still look noisy, but not much more so than they would be at that ISO speed.

With the Canon 6D, underexpose the shadows and you pay the price of increased noise and discoloration when you try to recover details in the shadows.

 For more technical information on the topic of ISO invariancy, see DPReview.com and many of their recent reviews of DSLRs, such as this page about the Canon 5Ds/r models. 

Apparently, the difference comes from where the manufacturer places the analog-to-digital circuitry: on the sensor (ISO invariant) or outboard on a separate circuit (ISO variant), and thus where in the signal path the amplification occurs when we boost ISO speed.


TEST #6 — Features

One could go on endlessly about features, but here I compare the two cameras on just a few key operating features very important to astrophotographers.

Nikon Intervalometer Start

Intervalometer:

The Canon 6D has none, though newer Canons do. The Nikon D750, as do many Nikons, has a built-in intervalometer (shown above), even with a deflickering “Exposure Smoothing” option. However, exposure time is limited to the camera’s maximum of 30 seconds. Any longer requires an outboard intervalometer, as with the Canon.

If you use your camera with any motion control time-lapse unit, then it becomes the intervalometer, negating any capability built into the camera. But it’s nice to have.

Small Advantage: Nikon


Interval Length:

REVISED JUNE 2020:

When taking time-lapse or star trail images with the Canon I can set an interval as short as 1 second between frames, for a minimum of gaps or jumps in the stars. With the Nikon, controlled internally by its built-in intervalometer, a 1-second interval is possible but only if you set the interval to 33 seconds for a 30-second shutter speed.

That’s true of Canon and Sony built-in intervalometers as well, because on all cameras setting the exposure to 30 seconds really gives you a 32-second exposure. A little known fact! So the interval between shutter firings has to be set to 33 seconds. It’s tricky.

Advantage: None to either


Nikon D750 with Radian

Tiltable LCD Screen:

The Canon 6D has none. The Nikon D750 has a very useful tilt-out screen as shown above. This is hugely convenient for all forms of astrophotography. Only cropped-frame Canons have tilt-out screens. This feature might add weight, but it’s worth it!

Big Advantage: Nikon


Dark Frame Buffer:

The Nikon has none. With Long Exposure Noise Reduction ON, the Canon 6D allows up to four exposures to be shot in quick succession before the dark frame kicks in and locks up the camera. (Put the camera into Raw+JPG.)

[JUNE 2020: With the Canon 6D MkII the buffer allows three frames to be taken in quick succession.]

This is very useful for deep-sky imaging, for acquiring a set of images for stacking that have each had a dark frame subtracted in-camera, with a minimum of “down-time” at the camera.

Big Advantage: Canon


Live View Screen Brightness:

As pointed out to me by colleague Christoph Malin, with the Nikon you cannot dim the screen when in Live View mode and with Exposure Simulation ON. So it can be too bright at night. With the Canon you can dim the Live View screen — the LCD Brightness control affects the screen both during Live View as well as during playback of images.

Small Advantage: Canon


Canon with GBTimelapse

Software Compatibility:

Canon EOS cameras are well supported by advanced software, such as GBTimelapse (above) that controls only Canons, not Nikons, in complex time-lapse sequences, and Nebulosity, popular among deep-sky imagers for DSLR control.

Small Advantage: Canon


My take-away conclusions: 

• Nikon DSLRs now are just as good for astrophotography as Canons, though that wasn’t always the case – early models did suffer from more noise and image artifacts than their Canon counterparts.

• Canon DSLRs, due to their sensor design, are more prone to exhibiting noise and image artifacts when images are greatly underexposed then boosted later in processing. Just don’t underexpose them – good advice for any camera.


All images and text are © 2015 Alan Dyer.

– Alan, August 27, 2015 & Revised June 25, 2020 / © 2015 Alan Dyer / www.amazingsky.com

Moonlight on the Prairie


The rising almost-Full Moon, a “Blue Moon” of July 30, 2015, rising behind a rustic old farmhouse near Bow Island, Alberta. The Moon sits in the pibk Belt of Venus with the blue shadow of the Earth below. This is a single frame from a 600-frame time-lapse sequence, taken with the Canon 6D and 16-35mm lens.

I present a short time-lapse vignette of scenes shot under moonlight on the Alberta prairie.

The movie linked below features sequences shot July 29 and 30, 2015 on beautifully clear moonlit nights at locations south of Bow Island, Alberta, on the wide open prairie. The three-minute video features two photogenic pioneer sites.

Circumpolar star trails over the historic but sadly neglected St. Anthony’s Church between Bow Island and Etzikom, Alberta. The Big Dipper is at left, Polaris at top. The Roman Catholic church was built in 1911 by English, Russian German immigrants. It served a dwindling congregation until 1991 when it closed. At that time workers found a time capsule from 1915 with names of the priest and parisioners of the day. In summer of 2014 the Church suffered its latest indignity when the iron cross on its steeple tower was stolen. It was there when I stopped at this Church on a site scouting trip in May 2014. I planned to return on a moonlit night and did on July 29, 2015. A nearby house had been torn down and the cross was now gone.  This is a stack of 300 6-second exposures with the Canon 6D at ISO 1600 and 16-35mm lens at f/2.8. Bright light from a 13-day Moon lights the scene, making for very short exposures. The ground comes from one exposure to keep shadows sharp. The final stars also come from another single exppsure taken two minutes after the last trail image. I used the Advanced Stacker Actions to stack the trails.

The church is the now derelict St. Anthony’s Church, a former Roman Catholic church built in 1911 by English and Russian-German immigrants. It served a dwindling congregation until as late as 1991 when it closed. At that time workers found a time capsule from 1915 with names of the priest and parisioners of the day.

The wood church seems to have been largely neglected since.

In the summer of 2014 the Church suffered its latest indignity when the iron cross on its steeple tower was stolen. I also shot in the pioneer cemetery of the Church.

Circumpolar star trails circling above an old rustic and abandoned house near Bow Island, Alberta, with illumination from the nearly Full Moon. Cassiopeia is near centre. Polaris is at top left.  This is a stack of 140 frames from a time-lapse sequence with additional frames added for the first and last stars, and the ground coming from a mean combine stack of 8 frames to reduce noise. Each frame is 10 seconds at f/4 with the 16-35mm lens and ISO 1600 with the Canon 6D. Stacked with Advanced Stacker Actions, using the Ultrastreaks effect, from within Photoshop.

The other site is a nearby farmhouse with photogenic textures and accompanied by rustic out buildings that are barely managing to stand.

Illumination was from a waxing gibbous Moon, just 1 to 2 days before the infamous “Blue Moon” of July 31. Its bright light turned the sky blue, and lit the landscape with the same quality as sunlight, because it is sunlight!


Enlarge the video to full screen for the full HD version.

For the technically inclined:

I shot the scenes with three cameras – a Canon 60Da, Canon 6D, and Nikon D750.

The Nikon, with a 24mm lens, was on the Dynamic Perception Stage Zero Dolly and Stage R panning unit, while the 60Da, with a 14mm lens, was on the compact Radian panning unit. The third camera, the 6D, with a 16-35mm lens, was on a fixed tripod for the star trail sequences and stills.

The music is by Adi Goldstein (AGSoundtrax.com), whose music I often use in my sequences. It just seems to work so well, and is wonderfully melodic and powerful. Thank you, Adi!

To process the several thousand frames that went into the final movie, I used Adobe Bridge and Adobe Camera Raw, supplemented by the latest Version 4.2 of LRTimelapse (lrtimelapse.com). Its new “Visual Deflicker” workflow does a beautiful job smoothing out frame-to-frame flickering in sequences shot in twilight under darkening lighting conditions. Thank you Gunther!

For the star trail sequences and the still images above I used the Advanced Stacker Actions from StarCircleAcademy.com. Unlike most other stacking programs, the Stacker Actions work from within Adobe Bridge and Photoshop directly, using the processed Raw images, with no need to create intermediate sets of JPGs. Thank you Steven!

— Alan, August 3, 2015 / © 2015 Alan Dyer / www.amazingsky.com 

The Milky Way over the Milk River


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.

The summer Milky Way shines over the Milk River and the sandstone formations of Writing-on-Stone Provincial Park.

Earlier this week I spent two nights shooting at a favourite site in southern Alberta, near the U.S. border. Here, the Milk River winds through a small canyon and coulees lined with eroded sandstone formations called hoodoos. Carved on those hoodoos are ancient graffiti – petroglyphs dating back hundreds of years recording life on the plains. Thus the name: Writing-on-Stone.

It’s a beautiful place, especially so at night. I was there to shoot video scenes for an upcoming “How to Photograph the Milky Way” tutorial. And to collect images for the tutorial.

Above is a shot that is one frame from a time-lapse sequence, one that captures a meteor and the Milky Way over the Milk River, with the Sweetgrass Hills of Montana in the distance.

The summer Milky Way over the Milk River Valley and sandstone formations of Writing-on-Stone Provincial park, in southern Alberta. On the horizon are the volcanic Sweetgrass Hills in Montana. The red tint at top is from an aurora active that night and the ground is partly illuminated by green auroral light from the north. The Summer Triangle stars are at top left. Sagittarius is on the horizon sinking into the low clouds at botton right which are illuminated by lights from Sweetgrass, Montana. Clouds and smoke from forest fires to the west cut down the transparency and clarity of the sky this night, especially toward the horizon.  This is a stack of 4 x 3-minute tracked exposures for the sky, and 4 x 5-minute untracked exposures for the ground, all with the 15mm Canon full-frame fish-eye and Canon 6D at ISO 1000, on the iOptron Sky-Tracker unit.

This image is from a set of exposures I took with the camera and ultra-wide 15mm lens tracking the turning sky, to prevent the stars from trailing in long exposures. A set of images with the tracker motor turned off supplied the sharp ground.

It shows the sweep of the summer Milky Way, with some clouds and forest fire smoke intruding to the south.

In both images the ground is green because, in part, it is being lit by an aurora display going on behind the camera to the north.

An aurora display to the northeast over the Milk River Valley and Writing-on-Stone Provincial Park in southern Alberta, night of July 22/23, 2015. The ground is lit by aurora light. The view is looking east to the rising autumn constellations of Cassiopeia and Perseus at left, and Andromeda and Pegasus at centre. The Milky Way runs from left to top centre. I shot this with the 15mm full-frame fisheye and Canon 6D. The sky is from one image, but the ground is from a stack of 4 images, mean combined, to smooth noise.

Here’s the view looking east, with a green aurora fringed with red lighting the northern sky.

The arc of the auroral oval as seen from southern Alberta, July 22/23, 2015, from Writing on Stone Provincial Park, looking north over the flat prairie. The Big Dipper is at left. This is a 4-segment panorama with the Canon 60Da and 16-35mm lens at 16mm, stitched in Photoshop.

The display on the night of July 22/23 formed a classic arc across the north. This was my panoramic view of the vast auroral oval that was wrapping around the planet at far northern latitudes. Here, I was at 49° north, almost on the Canada-U.S. border, and well south of the main oval.

In all, it was a magical two nights at a scenic and sacred site.

– Alan, July 24, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Solstice Sky at Dinosaur Park


Summer solstice twilight and circumpolar star trails over the badlands of Dinosaur Provincial Park, Alberta. Some bright noctilucent clouds are visible low on the northern horizon. I shot this June 15, 2015 as part of a shoot for a “star trail” video tutorial, as an example image. This is a stack of the first 200 frames of 275 shot for a time-lapse, each 15 seconds at f/2.8 with the Rokinon 14mm lens and Canon 6D at ISO 1600. I stacked them in Advanced Stacker Actions with the ultrastreak mode. The foreground comes from a mean blend of the first 8 frames, to smooth noise, and to provide a brighter foreground from early in the sequence when the sky and ground were brighter.

The stars circle the bright northern sky at solstice time over the Alberta Badlands.

I spent the evening and well into the night on Monday shooting at a favourite spot, Dinosaur Provincial Park in southern Alberta. The result of about an hour of shooting around midnight is the circumpolar star trail composite at top.

It shows the stars spinning about Polaris, while the northern horizon is rimmed with the bright glow of all-night twilight.

Particularly bright in the northwest are noctilucent clouds low on the horizon. These are high-altitude clouds near the edge of space catching the sunlight streaming over the pole at this time of year.

Noctilucent clouds (NLCs) over the silhouette of the badlands of Dinosaur Provincial Park in southern Alberta, on the night of June 15/16, 2015. The clouds remained low on the northern horizon and faded as the Sun angle dropped through the night but then reappeared in the northwest prior to dawn. The bright star at left is Capella, circumpolar at this latitude of 50° N.  This is a single exposure for 10 seconds at f/3.2 with the 16-35mm lens and at ISO 800 with the Canon 60Da.

They are a phenomenon unique to the weeks around solstice, and for our latitudes on the Canadian Prairies.

The close-up shot above shows their intricate wave-like formation and pearly colour. They faded though the night as the Sun set for the clouds. But they returned in the pre-dawn light.

If you live at mid-northern latitudes, keep an eye out for these clouds of solstice over the next month. It’s now their peak season.

– Alan, June 16, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Under an Endless Open Sky


Circumpolar star trails at dawn over the historic Butala homestead at the Old Man on His Back Prairie and Heritage Conservation Area in southwest Saskatchewan, taken May 2015. This is a stack of 70 frames from a larger time-lapse sequence, from the end of the sequence in the dawn twilight. Each exposure is 40 seconds with the 14mm lens at f/2.8 and Canon 60Da at ISO 1600. Stacked with Advanced Stacker Actions. The foreground comes from a stack of 8 of the final exposures, mean combined, to smooth noise.

The skies were spectacular at a pioneer homestead on the Saskatchewan prairie.

Canada’a province of Saskatchewan bills itself as the “Land of Living Skies,” and that was certainly true last week when I spent three perfect nights under some of the darkest skies in the country.

The location was the Old Man on His Back Prairie & Heritage Conservation Area, deep in dry southwest Saskatchewan, between Grasslands National Park and Cypress Hills Interprovincial Park, two favourite places of mine for nightscape photography and astronomy.

The Conservation Area reclaims and preserves original short grass prairie habitat. It is named for the formation to the west that is said to resemble the profile of Napi, the creator being of Siksika legends, who after creating the world, lay back here to rest.

The land was once a working ranch first settled by the Butala family. The white pioneer house in my photos dates from that time. It was built in Montana and moved here in the 1920s.

The waxing crescent Moon and Venus (above) over the old farm house at the Visitor Centre at the Old Man on His Back Natural and Historical Conservation Area in southwest Saskatchewan, May 20, 2015, on a very clear night. The old house was the original house lived in by the Butala family who settled the area in the 1920s. This is a single exposure taken as part of an 850-frame time-lapse sequence with the 14mm Rokinon lens and Canon 60Da camera.

In the mid-1990s Peter and Sharon Butala transferred their land to the Nature Conservancy of Canada, to create an island of original prairie amid the heavily grazed land around it.

A 360° panorama of the night sky and prairie landscape from the Visitor Centre and farmyard at the Old Man on His Back Prairie & Heritage Conservation Area in southwest Saskatchewan. The Milky Way arches across the eastern sky from north to south, while an aurora display (faint to the naked eye) glows in an arch of green and magenta across the northern horizon. The pioneer house was built in the 1920s and this was a working ranch until the 1990s when the land was turned over to the Nature Conservancy of Canada to turn into a natural area to preserve the short grass prairie habitat.  This a stitch of 8 segments, each a 1 minute untracked exposure at f/3.5 with the 15mm lens and ISO 4000 with the Canon 6D. Stitched with PTGui software. I shot these May 18, 2015.

For astronomers, the Area serves also as an island of darkness amid intruding light pollution. The region is very dark, with few lights and manmade sky-glows on the horizon.

My 360° panorama above shows that the greatest glows come from the arc of the aurora to the north and the arch of the Milky Way stretching across the sky. This is a stargazer’s paradise.

My 2-minute compilation of time-lapse videos and still images taken over three crystal clear nights attempts to capture the wonder of the night sky from such a dark site. Be sure to enlarge the video to full screen to view it.

It was in the little white house that Sharon Butala wrote some of her best-selling books retelling stories of her life on the prairie, notably The Perfection of the Morning, and Wild Stone Heart.

In the latter book, Sharon writes:

“At night the Milky Way glittered and gleamed above us, fathomlessly deep and numberless, the constellations wheeled slowly across the sky with the seasons, and the moon came and went, sometimes white as a maiden’s face, sometimes a looming orange sphere … under such an endless, open sky.”

– Sharon Butala, Wild Stone Heart (Harper Collins, 2000)

– Alan, May 25, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Nightscapes at Double Arch


Star Trails Behind Double Arch

The iconic Double Arch looks great under dark skies, moonlight, or painted with artificial light.

Last night, I returned to the Double Arch at Arches National Park, to capture a star trail series, starting from the onset of darkness at 9:30 p.m., and continuing for 2.5 hours until midnight, an hour after moonrise at 11:00 p.m. The lead image is the result.

I think it turned out rather well.

The Big Dipper is just streaking into frame at top right, as I knew it would from shooting here the night before. The bright streak at upper left is Jupiter turning into frame at the end of the sequence. Note how the shadow of the moonlit foreground arch matches the shape of the background arch.

On the technical end, the star trail composite is a stack of 160 frames, each 45 seconds at f/2.8 and ISO 3200, with the Canon 6D and 14mm lens. The foreground, however, comes from a stack of 8 frames taken toward the end of the shoot, as the moonlight was beginning to light the arches. An additional 45-second exposure taken a couple of minutes after the last star trail frame adds the star-like points at the “head” of the star trail streaks.

I used the excellent Advanced Stacker Actions from StarCircleAcademy to do the stacking in Photoshop.

Dark Sky Behind Double Arch

Before starting the star trail set, I took some initial short-exposure nightscapes while the sky was still dark. The result is the above image, of Double Arch in a dark sky. Passing car headlights provided some rather nice accent illumination.

On such a fine night I thought others might be there as well. Arches is a very popular place for nightscape imaging.

Sure enough, 6 others came and went through the early evening before moonrise. We had a nice time chatting about gear and techniques.

As expected, a few photographers came armed with bright lights for artificially lighting the arches. I kept my camera running, knowing any illumination they shone on the foreground wouldn’t affect my star trails, and that I’d mask in the foreground from frames taken after moonrise.

Photographer Lighting Double Arch

Here’s one frame from my star trail sequence where one photographer headed under the arch to light it for his photos. It did make for a nice scene – a human figure adds scale and dimension.

However, I always find the light from the LED lamps too artificial and harsh, and comes from the wrong direction to look natural. I also question the ethics of blasting a dark sky site with artificial light.

On a night like this I’d rather wait until moonrise and let nature provide the more uniform, warmer illumination with natural shadows.

Big Dipper over Double Arch

As an example, I took this image the night before using short exposures in the moonlight to capture the Big Dipper over Double Arch. When I shot this at 11 p.m. I had the site to myself. Getting nature to provide the right light requires the photographer’s rule of “waiting for the light.”

– Alan, April 7, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Orion Over and Through Turret Arch


Orion Star Trails Through Turret Arch

What a fabulous night for some nightscapes at Arches National Park, Utah.

I’m at Arches National Park for two nights, to shoot the stars over its amazing eroded sandstone landscape.

I started the night last night, April 6, shooting Orion over Turret Arch while the sky was still lit by deep twilight. That image is below. It shows Orion and the winter sky, with bright Venus at right, setting over the aptly-named Turret Arch.

I scouted the location earlier in the day and measured in person, as expected from maps, that the angles would be perfect for capturing Orion over the Arch.

But better still would be getting Orion setting through the Arch. That’s the lead photo at top.

I shot the star trail image later in the evening, over half an hour. It uses a stack of 5 exposures: a single, short 30-second one for the initial point-like stars, followed by a series of four 8-minute exposures to create the long star trails. The short exposure was at ISO 4000; the long exposures at ISO 250. All are with the Rokinon 14mm lens.

Orion Over Turret Arch

Arches is a popular and iconic place for nightscape photography.

I thought I’d likely not be alone, and sure enough another pair of photographers showed up, though they were armed with lights to illuminate the Arches, as many photographers like to do.

I shot this from afar, as they lit up the inside of Turret Arch where I had been earlier in the night.

Photographer Lighting Turret Arch

I prefer not to artificially illuminate natural landscapes, or do so only mildly, not with bright spotlights. We traded arches! – while I shot Turret, the other photography couple shot next door at the North and South Window Arches, and vice versa. It all worked out fine.

Later in the night, after moonrise, I shot next door at the famous Double Arch. Those moonlit photos will be in tomorrow’s blog.

It was a very productive night, and a remarkable experience shooting at such a location on a warm and quiet night, with only a fellow photographer or two for company.

– Alan, April 7, 2015 / © 2015 Alan Dyer / www.amazingsky.com

A Stellar Occultation by the Moon


Impending Occultation of Beta Capricorni

The double star Beta Capricorni disappears in a wink behind the Earthlit edge of the Moon.

The evening of Wednesday, November 26 provided a bonus celestial event, the eclipse of a double star by the Moon.

The star is Beta Capricorni, also known as Dabih. I had a ringside seat Wednesday night as the waxing Moon hid the star in what’s called an occultation.

Dabih is a wide double star, composed of a bright magnitude 3 main star, Beta1 Capricorni, and a fainter magnitude 6 companion, Beta 2 Capricorni. You can see both in the still image view at top. Their wide separation makes them easy to split in binoculars.

In reality, they are separated in space by an enormous gap of 21,000 times the distance from the Earth to the Sun. By comparison, distant Pluto lies an average of just 40 times the Earth-Sun distance.

With such a wide separation Beta1 and Beta2 take an estimated 700,000 years to orbit each other.

Beta1 is a giant orange star 600 times more luminous than our own Sun and 35 times bigger. Beta2 is a blue subgiant 40 times more luminous that the Sun.

Adding to the complexity of the system, Beta2 is also a close double, while Beta1 is a tight triple star, making for a quintuple star system.

The movie below records each occultation, first of the fainter blue Beta2 star, then of the brighter Beta1 star.

Each occultation happens in an instant to the eye. However, stepping through the video shows that the brighter star took 4 video frames to dim, about 1/10th of a second. Whether this is real, due to the star’s giant size, or just an effect of the twinkling of the atmosphere, is questionable.

Technical notes:

The still photo is a “high dynamic range” stack of 12 exposures from 4 seconds to 1/500th second, taken with the Canon 60Da camera at ISO 400, to capture the huge range in brightness, from the dark side of the Moon and stars, to the bright sunlit crescent. I used Photoshop’s HDR Pro module to stack the images and Adobe Camera Raw in 32-bit mode to do the tone-mapping, the process that compresses the brightness range into a final image.

I shot the video with the 60Da camera as well, setting it to ISO 6400, and using its video mode to record real-time video clips, both in HD 1920×1080 for the wide-field “establishing shots,” and in its unique 640×480 Movie Crop mode for the close-ups of the actual occultations. Those two clips appear as inset movies. I edited and processed the clips, plus added the titles, using Photoshop and its video capabilities.

All were shot from New Mexico with the TMB 92mm refractor at f/5.5.

– Alan, November 28, 2014 / © 2014 Alan Dyer

Truly Interstellar


M26 Open Cluster and NGC 6712 Globular Cluster

We gaze into the interstellar depths of the Milky Way through uncountable stars.

In this telescopic scene we look toward the Scutum Starcloud, and next spiral arm in from ours as we gaze toward the core of the Galaxy.

The field is packed with stars, seemingly crowded together in interstellar space. In fact, light years of empty space separate the stars, even in crowded regions of the Milky Way like this.

Two dense clusters of stars stand out like islands in the sea of stars. At lower right is Messier 26, an open cluster made of a few dozen stars. Our young Sun probably belonged to a similar family of stars billions of years ago. M26 lies 5,200 light years away.

At upper left is a condensed spot of light, made of hundreds of thousands of density packed stars in the globular cluster known only as NGC 6712. Though much larger and denser than M26, NGC 6712 appears as a tiny spot because of its remoteness – 23,000 light years away, a good part of the distance toward the centre of the Galaxy.

Look carefully (and it may not be visible on screen) and you might see a small green smudge to the left of NGC 6712. That’s a “planetary nebula” called IC 1295. It’s the blown off atmosphere of an aging Sun-like star. It’s what our Sun will become billions of years from now.

At top is a vivid orange-red star, S Scuti, a giant pulsating star nearing the end of its life.

A truly interstellar scene.

– Alan, November 9, 2014 / © 2014 Alan Dyer

 

 

Red Moon over Writing-on-Stone


Red Moon over Writing-on-Stone

The red eclipsed Moon shines over the Milk River, with Orion over the Sweetgrass Hills.

This was the scene at 4:45 this morning, October 8, from my observing site for the lunar eclipse, Writing-on-Stone Provincial Park in southern Alberta.

The eclipsed red Moon shines at far right over the Milk River and sandstone formations of Writing-on-Stone Park, home to ancient petroglyphs, and a sacred site to First Nations people.

At left are the Sweetgrass Hills across the border in Montana. Above shine the stars of Orion, with his Dog Star Sirius below. Above is Taurus, with Aldebaran and the Pleiades cluster.

The night was fairly clear for the hour of totality, though with high haze fuzzing the stars and Moon. But considering the cloud I had driven 3 hours to escape I was happy.

Self-Portrait at Oct 8, 2014 Total Lunar Eclipse

Here I am in a 5:30 a.m. selfie by starlight and moonlight, with the clouds I had escaped now rolling in to cover the Moon as it began to emerge from Earth’s shadow.

No matter. I had captured what I had come for: the nightscape above (with a 14mm lens), and close-ups shot through this telescope gear, one of which I featured in my previous post.

– Alan, October 8, 2014 / © 2014 Alan Dyer

 

Aurora and Airglow Panorama


Aurora & Airglow Panorama

The sky lights up in greens and reds from aurora and airglow.

This has been a good week for aurora watching. Friday night the Northern Lights danced again, this time in a sky already filled with a more subtle phenomenon, airglow.

Airglow adds its own bands of reds and greens across the sky, seen here as arcs from left (west) to centre (north) and into the east. Airglow is light from fluorescing air molecules releasing energy absorbed from the Sun by day.

The aurora adds the brighter green curtains across the north with vertical beams of yellow and red shooting up.

A weird structure which I assume is from the aurora is the sharp-edged yellow band at left in the west. It lasted no more than 2 or 3 minutes, enough to record in three frames of this 7-segment 180° panorama taken near home at an array of grain bins, now filled from the harvest.

To the west and east urban light pollution adds glows of yellow to the horizon.

– Alan, September 27, 2014 / © 2014 Alan Dyer

 

Autumn Stars Rising over Dinosaur Park


Autumn Sky Rising over Badlands

The autumn constellations rise into a colourful sky at Dinosaur Provincial Park, Alberta.

Last night the sky started out beautifully clear but as it got darker it was apparent even to the eye that the sky wasn’t really dark, despite the lack of any Moon.

The camera captured the culprit – extensive green airglow, to the east at right. A faint aurora also kicked up to the north, at left, adding a red glow. Light pollution from gas plants nearby and from Brooks 50 km away added yellow to the sky scattered off haze and incoming cloud.

The sky colours added to the scene of the autumn constellations of Cassiopeia, Andromeda, Perseus and Pegasus rising in the east. The Andromeda Galaxy is at centre. The Pleiades is (are?) just rising over the hill.

This is a composite of five stacked and tracked exposures for the sky (with the camera on the Star Adventurer tracking mount) and four stacked but untracked exposures I took at the end of the sequence for the sharp ground (I just turned the tracker motor off for these).

– Alan, September 26, 2014 / © 2014 Alan Dyer

 

Red Rock Canyon by Starlight


Red Rock Canyon by Starlight

The Milky Way illuminates the trail at Red Rock Canyon, in Waterton Lakes National Park.

Last Sunday night was incredibly clear. I trekked around Waterton Lakes National Park, taking panoramas at various sites. This is Red Rock Canyon, a popular spot by day.

By night it is one of the darkest accessible places in the Park. Here the landscape is lit only by the light of the stars and Milky Way.

This is a composite of two exposures, both on a tripod with no tracking of the sky motion:

– one exposure was 60 seconds for the sky to minimize star trailing.

– the other exposure, taken immediately following, was 3 minutes for the ground, to bring out detail in the dark, starlit landscape.

I blended the two exposures in Photoshop, creating a single image with the best of both worlds, earth and sky.

– Alan, September 25, 2014 / © 2014 Alan Dyer

 

Galaxy and Glacier


Milky Way over Athabasca Glacier

The centre of the Milky Way Galaxy sets behind the Athabasca Glacier and Columbia Icefields. 

This was one of the clearest nights I have ever seen at the Icefields. Unlike most nights, last night not a whiff of high cirrus was wafting off the great sheets of ice in Jasper National Park, leaving the sky pristine for the Milky Way to shine over the glaciers.

I shot this image Sunday night, September 14, from the approach road down to the tongue of the Athabasca Glacier. At this time of year, the Milky Way sets directly behind the glacier in the early evening. The angles were perfect.

At left is the glacier-clad peak of Mt. Andromeda, indeed named for the constellation and mythological princess. It is lit just by starlight. The waning Moon didn’t rise until 11:30 p.m., leaving me a couple of hours of dark sky to shoot these and other images.

To record the scene I shot and composited two versions of the image:

– one from a stack of four tracked images where the camera followed the stars on a small mount (the Sky-Watcher Star Adventurer) in order to build up the image and, admittedly, record far more detail and colour than your eye could ever see in the Milky Way.

– the sharp landscape comes from another stack of four images where I turned the tracking drive off so the ground wouldn’t blur. Stacking them helps reduce noise.

I composited the two sets of images, masking the sky from the untracked images and the ground from the tracked images. Perhaps that’s all a bit of trickery but the scene is real – the Milky Way really was there behind Athabasca Glacier.

Each sky exposure was 3 minutes, each ground exposure 4 minutes, all with the 24mm lens at f/2.5 and the Canon 6D at ISO 1250.

– Alan, September 15, 2014 / © 2014 Alan Dyer

 

Stars on Ice – The Columbia Icefields by Moonlight


Star Trails over Columbia Icefields

The stars trail over the glaciers of the Columbia Icefields.

What an amazing night this was! You rarely get pristine cloudless skies over the Icefields. Some cloud is almost always blowing off the ice. But last Saturday in Jasper National Park was as clear as it gets.

The Moon was bright, as a waxing gibbous just off frame at left. It lit the landscape like it was day.

I shot with two cameras, one doing a time-lapse motion control sequence panning across the scene. The other was a fixed camera shooting 20-second exposures at 1-second intervals. The resulting frames from the fixed camera, 270 in this case, are multi-purpose:

– I stacked about 100 of them to make the star trail composite above. Two frames supplied the stars at the beginning and end of the trails. Another single frame supplied the ground, to avoid the shadows being blurred by the Moon’s motion if you used the ground composited from all 100 frames.

– I can also take the full set of 270 frames and sequence them into a time-lapse movie of the stars moving over the landscape.

Stars over the Columbia Icefields Panorama

Before beginning the time-lapse sequences I shot this 180° panorama, made of 5 segments stitched in PTGui software. It extends from the southwest at left, where the Milky Way is barely visible, to the north at right, with the Big Dipper over the Icefields Parkway.

Click on it for a bigger view.

Shooting at the Icefields

This is the camera setup, with the camera on the right taking the star trail image I feature at top.

The Athabasca Glacier is at left, the Stutfield Glacier at right.

Icefields Parking Lot at Night

Midnight under moonlight is when to see the Icefields! This is the lower parking lot, at the start of the trail up to Athabasca Glacier. This is packed with cars, RVs and buses by day, but at night I was the only one there.

– Alan, Sept, 8, 2014 / © 2014 Alan Dyer

 

Stars over Mt. Edith Cavell


Mt Edith Cavell by Starlight

The stars of the summer sky shine over the North Face of Mt. Edith Cavell.

The valley below Mt. Edith Cavell in Jasper National Park is one of the most impressive locations in the Canadian Rockies. At few other sites do you get the sense of standing at the foot of a vertical mountain face.

I shot this view last Friday night, when the waxing Moon was behind the mountain, lighting the clouds and sky but not the mountain and valley directly.

But enough scattered light came from the sky to light the foreground and mountain face to make a nice photo with detail in both earth and sky.

Use of highlight and shadow recovery in Adobe Camera Raw also helps a lot!

Mt. Edith Cavell Trail at Twilight Panorama

This view is a 360° ground-to-zenith panorama I shot earlier in the evening in twilight. It’s from the Trail of the Glacier path, where the path crosses Cavell Creek.

Mt. Edith Cavell was named in 1916 after the World War One nurse who was executed by the Germans for assisting allied soldiers escape occupied Belgium.

– Alan, September 8, 2014 / © 2014 Alan Dyer

 

Pyramid Island Sky Panorama


Panorama from Pyramid Island Boardwalk, Jasper Park

The sky presents a panoramic show from Pyramid Island in Jasper National Park.

What a wonderful place to watch the stars. Last night I walked out to Pyramid Island in Jasper, via the historic boardwalk built in the 1930s. The site provides a panorama view around the lake and sky.

To the left is the “mainland.” Just left of centre the waxing gibbous Moon is setting over Pyramid Lake.

To the right of centre, the boardwalk leads out the small island, with Pyramid Mountain behind it.

To the right of the frame, a faint aurora glows to the northeast over the still waters of the lake.

This is a 360° panorama shot with the 15mm full-frame fish-eye lens in portrait orientation, with the segments stitched with PTGui software.

Big Dipper over Pyramid Mountain from Pyramid Island

After shooting some panoramas I walked to the end of the island and shot this view looking north and northwest to Pyramid Mountain. The Big Dipper is to the right of the peak, and the aurora lights up the northern horizon at right.

As I shot these images, the night was absolutely quiet. Until the wolves began to howl at the north end of the lake, in mournful howls that echoed across the waters.

It was one of the most spine-chilling moments I’ve experienced in many years of shooting landscapes at night.

– Alan, September 5, 2014 / © 2014 Alan Dyer

 

 

Mars, Saturn and the Milky Way in Twilight


Mars, Saturn & Milky Way over Ranch Corral

Mars and Saturn meet in conjunction beside the Milky Way.

As it was getting dark two nights ago, I shot this view of Mars and Saturn (the “double star” at right, with Mars below Saturn) paired together now in the evening twilight. The location was Grasslands National Park, on the Park’s main loop tour road.

At the centre of the image is Scorpius and its bright star Antares, just behind the gate of the old corral.

At left are the star clouds of the Milky Way and the galactic core. Just above the horizon are the naked-eye star clusters Messier 6 and Messier 7, the most southerly of the popular Messier objects.

The sky is blue from the last of the twilight glow.

The image is a composite of two exposures, both 1 minute but one tracking the sky and one with the drive turned off to provide the sharper foreground.

– Alan, August 29, 2014 / © 2014 Alan Dyer

 

Standing Under the Stars at Grasslands Park


Standing Under the Stars at Grasslands Park

Grasslands National Park is one of the finest places in Canada to revel in the dark night sky.

This was the scene last night, in far south Saskatchewan, under clear and super dark night skies, at long last after a week of rain, wind and wintery cold.

I’m at Grasslands National Park south of Val Marie, Saskatchewan, to shoot night sky panoramas in what must rank as Canada’s darkest Dark Sky Preserve.

The park itself is new, created only a decade and half ago. It preserves original prairie grasses and is home to unique and rare species. Bison roam here, allowing you to travel back to pre-European times as you gaze out onto a landscape much as it was for thousands of years.

But look up at night and you can gaze at a sky as it was seen for thousands of years, mostly unblemished by the artificial glows of light pollution. Grasslands National Park is a “dark sky preserve,” allowing visitors to see the stars and Milky Way as they should be seen.

I shot this 360° panorama from the Eagle Butte Loop Trail just inside the boundary of the Park. The main hill is 70 Mile Butte, a landmark to the early NorthWest Mounted Police as it lay 70 miles from their posts at Wood Mountain to the east and Eastend to the west.

This view looks out across the farmland to the west and a handful of yard lights. But little else spoils the view around the rest of the horizon. The last vestiges of evening twilight provide a backdrop for the lone silhouette.

The Milky Way arches overhead, and some bands of green airglow, a natural night sky phenomenon, stretch from east to west. The centre of the Milky Way Galaxy lies to the far right, with its glowing clouds of stars.

– Alan, August 26, 2014 / © 2014 Alan Dyer

Table Mountain Time-Lapses


Table Mountain Star Trails-Circumpolar Elastic Effect

I present a set of short time-lapse videos shot at the Table Mountain Star Party.

At the star party in Washington state last week I shot about a 3-hour-long set of images each night for assembly into time-lapse movies. Here’s the compilation.

 

Click the Enlarge button for a full-screen view.

For the first two clips I used the eMotimo motion controller to pan across the star party field looking south to the Milky Way.

For the last two clips I used a static camera aimed north to capture the turning sky around the north celestial pole. I took the same 350 frames and assembled them two ways: as a standard movie and as an “accumulating star trails” movie where the stars seem to draw themselves across the sky like a sky full of comets.

That clip cross-fades to the still image above, created with the Advanced Stacker Plus actions that automatically stacks and blends images via a choice of effects. I used the “elastic stars” effect for the still image.

Many thanks to the organizers and volunteers at the Table Mountain Star Party for the opportunity to attend and speak at the party. I was a great three nights. I highly recommend the site and event.

– Alan, August 3, 2014 / © 2014 Alan Dyer

 

Mount Kobau Nightscapes


Big Dipper Down the Road

The pines and sagebrush landscape of the summit of Mount Kobau are illuminated by the light of just the stars and Milky Way.

This collection of images from Monday night, July 28, captures the night sky above and the land below in classic “nightscapes.”

I took all of these with a camera on a static tripod, with no tracking system involved here. All are about 40-second exposures at ISO 3200 to 6400 with a fast 24mm lens at f/2.5 on a Canon 6D.

However, for the image above I composited two exposures: a shorter 40 second shot for the sky and a longer 1 minute 40 second shot for the ground. I used Photoshop’s Quick Selection tool to make a rough selection of the ground, then the Refine Mask and Smart Radius tool to refine the edge to precisely mask the sky separately from the ground, for individual processing.

The top image shows the Big Dipper and a well-timed meteor, at the end of the summit road on Mt. Kobau, near Osoyoos, BC.

Big Dipper & Arcturus from Mt Kobau

This image takes in the Big Dipper at right pointing down to Arcturus at left. I used Photoshop’s Content Aware Fill to neatly eliminate a power pole and wires.

Sagebrush and Stars

Looking southwest reveals the Milky Way above the sagebrush and pine trees. This is a single exposure, with the ground processed with Shadow detail recovery to bring out the starlit ground.

Pleiades Rising Down the Road

This image, taken about 2 a.m., records the Pleiades star cluster rising down the end of the summit road, with Capella at left. It is a dual-exposure composite: 40 seconds for the sky and 1m40s for the ground.

I gave a talk at this year’s Mt. Kobau Star Party on how to shoot these kinds of nightscapes, illustrated with some of these images shot on site the night before. Very nice!

– Alan, July 30, 2014 / © 2014 Alan Dyer

 

Swirling Stars at a Star Party


Table Mountain Star Trails-Circumpolar Elastic Effect

The stars of the northern sky swirl in circles around the North Star.

This is admittedly a fanciful effect but an attractive one. The above image records the rotating night sky as it spins around the north celestial pole near Polaris. I stacked 250 image to create this concentric star swirl.

To produce the image I used the excellent Advanced Stacker Actions from StarCircleAcademy, using the new version 14e actions. They include this novel “elastic” effect which produces trails with point-like stars at the beginning and end of the trails.

Table Mountain Star Party Star Trails #1

Another variation, the Short Comets effect, produced this image, with the stars turned into swirling comets.

I took the images for these composites at the Table Mountain Star Party near Oroville, Washington last week under superb skies. The same images that went into these still image stacks can be used to create time-lapse movies.

– Alan, July 29, 2014 / © 2014 Alan Dyer

Circling Stars Over the Open Range


Reesor Ranch Circumpolar Star Trails

The stars swirl in circles above the big sky country of the Canadian Prairies.

For these images I set the camera to take hundreds of images over the course of about 4 hours, then stacked about 100 frames for each of the composites. I stacked the images with the application StarStax

The result shows the stars circling the North Celestial Pole and Polaris in the northern sky. The top image is from earlier in the night when the Moon was still up lighting the landscape.

Reesor Ranch Circumpolar Star Trails v2

The image above is from late in the night, after moonset, and with the glow of dawn beginning to brighten the northern sky. Some low noctilucent clouds are also appearing on the horizon.

This was a beautiful night at Reesor Ranch in Saskatchewan, on the edge of Cypress Hills Interprovincial Park, on the Alberta-Saskatchewan border. I’ve just wrapping up a week of shooting here with clear nights every night but two. The hard drives are full!

– Alan, July 11, 2014 / © 2014 Alan Dyer

 

The Christmas Sky of 2013


Orion & Winter Sky (Christmas 2013)

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” ‘Twas the night of Christmas, and all across the sky,

All the stars were twinkling, and Orion shone on high.”

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Here’s my Christmas postcard, presenting the winter stars and constellations as they appeared over my Alberta backyard on Christmas night. The night was clear and calm, and not too cold.

Orion stood “on high” in the south, above bright Sirius, and below even brighter Jupiter at left, now blazing away in Gemini.

The winter Milky Way runs down the sky from Perseus at top to Canis Major on the horizon.

Merry Christmas to all and to all a good night!

– Alan, December 25, 2013 / © 2013 Alan Dyer

Venus in the Moonlight


Venus at Chiricahua National Monument (Dec 15, 2013) #3

Venus blazes brightly in the moonlit sky in the Chiricahua Mountains of Arizona.

This was the view last night, from Massai Point at the summit of the Chiricahua Mountains, looking southwest toward Venus in the blue moonlit sky. A bright waxing gibbous Moon provided the illumination, turning night into day in these long exposures.

I started my trek around Arizona and New Mexico here, at Chiricahua National Monument two weeks ago, on December 3, when I took some sunset shots.

Venus at Chiricahua National Monument (Dec 15, 2013) #1

I end my trip by returning to the Chiricahuas, but now with a nearly Full Moon in the sky.

I saw this scene two weeks ago but didn’t shoot it then. So I returned to capture Venus at the end of a moonlit road, shining above the volcanic rock formations that are the distinctive feature of the National Monument.

Now, it’s home to Alberta and the snow and cold.

– Alan, December 16, 2013 / © 2013 Alan Dyer

 

The Summer Triangle Stars


Summer Triangle in the Milky Way

The trio of Summer Triangle stars flank the Milky Way in the dying days of summer.

I shot the featured image above two nights ago on a perfect late summer night from home. Skies were dark and transparent, with no aurora and little airglow to taint the sky.

The image takes in the Summer Triangle stars of Vega (top), Deneb (left) and Altair (bottom). Vega and Altair straddle the summer Milky Way, but Deneb lies right in the thick of it, way down the Local Arm that we live in. Vega and Altair are nearby normal stars, only 25 and 16 light years away. But Deneb is a blue supergiant, shining from 1400 light years away, and one of the most luminous stars in the catalog.

The Milky Way through this area of sky is riven by twisting lanes of interstellar dust. A particularly dark patch sits above Deneb at top left. Then below Deneb the Milky Way gets split by the Great Rift that continues down into Aquila and Ophiuchus at lower right.

All along this part of the Milky Way, particularly around Deneb, the camera picks up a string of glowing red nebulas where stars are forming. The red comes from hydrogen atoms emitting deep red light, as hydrogen is wont to do.

Summer Milky Way from Backyard (Sept 9, 2013)

This image is from a couple of nights earlier. I used a wider angle lens to take in the full sweep of the summer Milky Way, from Sagittarius skimming the horizon, to Cassiopeia past the zenith at the top. You can see the Summer Triangle in the top half of the image, the part of the sky now overhead on early September nights from the northern hemisphere.

I took both shots with a filter-modified Canon 5D MkII placed on a little iOptron SkyTracker for tracked long exposures (4 to 5 minutes). The main image was with a 24mm Canon lens, the bottom image with a 14mm Rokinon lens.

– Alan, September 12, 2013 / © 2013 Alan Dyer

 

The Great Arc of the Milky Way


Milky Way Panorama (Sept 4, 2013)

The Milky Way sweeps in a great arch of light across the sky.

It’s been a wonderful week for shooting the Milky Way. I had a very clear night on Tuesday but ventured no further than a few hundred feet from home to the harvested canola field next door.

The Milky Way was beautifully placed, as it always is at this time of year, right across the sky from northeast to southwest, with the starclouds of Cygnus passing directly overhead.

The top photo is a panorama of 8 shots, with a camera on a tripod, and each exposure being just 60 seconds with a 14mm lens in portrait orientation. I stitched the segments with PTGui software, rendering the scene with its spherical projection mode which wraps the dome of the sky onto a flat surface in a way that retains the zenith detail as your eye saw it, but greatly distorts the extremities of the scene at either end.

My house is at lower right.

Milky Way over Harvest Field (Sept 4, 2013)

For this image, I used the same lens to take a single view from horizon to well past the zenith. Here the camera was tracking the stars for a set of stacked 5-minute exposures to grab even more detail in the Milky Way.

What stands out as much as the Milky Way are the green fingers of airglow stretching across the sky. These were invisible to the eye but the camera sure picks them up.

Airglow is caused by oxygen atoms, in this case, fluorescing at night as they release some of the energy they absorbed by day. It’s not aurora and generally covers more of the sky, sometimes with a diffuse glow or, as here, with more structured bands that slowly shift over minutes. It varies from night to night and can occur at any latitudes. But usually only cameras pick it up. To the eye, airglow just makes the sky look inexplicably a little less dark than you think it should be on such a clear night.

– Alan, September 7, 2013 / © 2013 Alan Dyer

 

The Milky Way over Milk River


Milky Way over Writing-on-Stone Park #2 (Sept 1, 2013)

The summer Milky Way sets over the Milk River on the last weekend of the summer.

This was the view last night, Sunday, September 1, from the Visitor Centre hill overlooking the spectacular Milk River valley and the sandstone formations of Writing-on-Stone Provincial Park, Alberta.

The Milk River winds around the park’s campsite, filled on a beautiful long weekend with campers enjoying the clear skies and temperatures in the 30s by day. At night, conditions were perfect. Warm, dry, no bugs, no wind. The best.

I set up two cameras: one for a day-to-night time lapse and one for a time-lapse panning the scene as the Milky Way moved to the west. These two images are frames from the latter.

Above is a shot from later in the evening when the sky was dark …

Milky Way over Writing-on-Stone Park (Sept 1, 2013)

… while this image is from earlier in the shoot, when the last of the blue twilight still lit the sky and the camera was aimed a little more to the east.

On the horizon at left in the image above lie the Sweetgrass Hills of Montana, a prominent landmark in southern Alberta. The yellow sky glows are from towns in northern Montana.

Lights from the campground and car headlights illuminate the landscape and the eroded hoodoo formations.

Writing-on-Stone Park preserves ancient rock petroglyphs that record scenes from before and after contact with Europeans. It is a sacred site to First Nations people and is a marvellous place for stargazing.

– Alan, September 2,