I had the chance to test out an early sample of Canon’s new EOS Ra camera designed for deep-sky photography.
Once every 7 years astrophotographers have reason to celebrate when Canon introduces one of their “a” cameras, astronomical variants optimized for deep-sky objects, notably red nebulas.
In 2005 Canon introduced the ground-breaking 8-megapixel 20Da, the first DLSR to feature Live View for focusing. Seven years later, in 2012, Canon released the 18-megapixel 60Da, a camera I still use and love.
Both cameras were cropped-frame DSLRs.
Now in 2019, seven years after the 60Da, we have the newly-released EOS Ra, the astrophoto version of the 30-megapixel EOS R released in late 2018. The EOS R is a full-frame mirrorless camera with a sensor similar to what’s in Canon’s 5D MkIV DSLR.
Here, I present a selection of sample images taken with the new EOS Ra.
Both versions of the EOS R have identical functions and menus.
The big difference is that the EOS Ra, as did Canon’s earlier “a” models, has a factory-installed filter in front of the sensor that transmits more of the deep red “hydrogen-alpha” wavelength emitted by glowing nebulas.
Normal cameras suppress much of this deep-red light as a by-product of their filters cutting out the infra-red light that digital sensors are very sensitive to, but that would not focus well.
I was sent an early sample of the EOS Ra, and earlier this autumn also had a sample of the stock EOS R.
Both were sent for testing so I could prepare a test report for Sky and Telescope magazine. The full test report will appear in an upcoming issue.
• How the Ra compares to previous “a” models and third-party filter-modified cameras
• How the Ra works for normal daylight photography
• Noise levels compared to other cameras
• Features unique to the EOS Ra, such as 30x Live View focusing
UPDATE — November 25, 2019
As part of further testing I shot the Heart and Soul Nebulas in Cassiopeia through my little Borg 77mm f/4 astrograph with both the EOS Ra and my filter-modified 5D MkII (modified years ago by AstroHutech) to compare which pulled in more nebulosity. It looked like a draw.
Both images are single 8-minute exposures, taken minutes apart and developed identically in Adobe Camera Raw, but adjusted for colour balance to equally neutralize the sky background. The histograms look similar. Even so, the Ra looks a little redder overall. But keep in mind a sky or nebula can be made to appear any shade of red you like in processing.
The question is which camera shows more faint nebulosity?
The modified 5D MkII has always been my favourite camera for this type of astrophotography, picking up more nebulosity than other “a” models I’ve tested, including the Nikon D810a.
But in this case, I’d say the EOS Ra is performing as well as, if not better than the 5D MkII. How well any third-party modified camera you buy now performs will depend which, if any, filter the modifier installs in front of the sensor. So your mileage will vary.
For most of my other testing I shot through my much-prized Astro-Physics Traveler, a 105mm aperture f/6 apochromatic refractor on the Astro-Physics Mach1 mount.
To connect the EOS Ra (with its new RF lens mount) to my existing telescope-to-camera adapter and field flattener lens I used one of Canon’s EF-EOS R lens adapters.
The bottom line is that the EOS Ra works great!
It performs very well on H-alpha-rich nebulas and has very low noise. It will be well-suited to not only deep-sky photography but also to wide-field nightscape and time-lapse photography, perhaps as Canon’s best camera yet for those applications.
WHAT ABOUT THE PRICE?
The EOS Ra will sell for $2,500 US, a $700 premium over the cost of the stock EOS R. Some complain. Of course, if you don’t like it, you don’t have to buy it. This is not an upgrade being forced upon you.
As I look at it, it is all relative. When Nikon’s astronomy DSLR, the 36 Mp D810a, came out in 2015 it sold for $3,800 US, $1,300 more than the EOS Ra. It was, and remains a fine camera, if you can find one. It is discontinued.
A 36 Mp cooled and dedicated CMOS astro camera, the QHY367, with the same chip as the D810a, goes for $4,400, $1,900 more than the Ra. Yes, it will produce better images I’m sure than the EOS Ra, but deep-sky imaging is all it can do. At a cost, in dollars and ease of use.
And yes, buying a stock EOS R and having it modified by a third party costs less, and you’ll certainly get a good camera, for $300 to $400 less than an Ra. But …
• The EOS Ra has a factory adjusted white balance for ease of “normal” use — no need to buy correction filters. So there’s a $$ saving there, even if you can find clip-in correction filters for the EOS R — you can’t.
• And the Ra retains the sensor dust cleaning function. Camera modifier companies remove it or charge more to reinstall it.
• And the 30x live view magnification is very nice.
• The EOS Ra also carries a full factory warranty.
Do I wish the EOS Ra had some other key features? Sure. A mode to turn all menus red would be nice. As would an intervalometer built-in, one that works with the Bulb Timer to allow sequences of programmed multi-minute exposures. Both could be added in with a firmware update.
And providing a basic EF-EOS R lens adapter in the price would be a welcome plus, as one is essential to use the EOS Ra on a telescope.
That’s my take on it. I’ll be buying one. But then again I bought the 20Da, twice!, and the 60Da, and I hate to think what I paid for those much less capable cameras.
BONUS TEST — The RF 15-35mm L Lens
Canon is also releasing an impressive series of top-class RF lenses for their R mirrorless cameras. The image below is an example astrophoto with the new RF 15-35mm f/2.8 L zoom lens, an ideal combination of focal lengths and speed for nightscape shooting.
Below is a further set of stacked and processed images with the RF 15-35mm L lens, taken in quick succession, at 15mm, 24mm, and 35mm focal lengths, all shot wide open at f/2.8. The EOS Ra was on the Star Adventurer tracker (as below) to follow the stars.
Click or tap on the images below to view a full-resolution version for closer inspection.
The RF 15-35mm lens performs extremely well at 15mm exhibiting very little off-axis aberrations at the corners.
Off-axis aberrations do increase at the longer focal lengths but are still very well controlled, and are much less than I’ve seen on my older zoom and prime lenses in this focal length range.
The RF 15-35mm is a great complement to the EOS Ra for wide-field Milky Way images.
I was impressed with the new EOS Ra. It performs superbly for astrophotography.
A new low-cost sky tracker promises to simplify not only tracking the sky but also taking time-lapses panning along the horizon. It works but …
If you are an active nightscape photographer chances are your social media feeds have been punctuated with ads for this new low-cost tracker from MoveShootMove.com.
For $200, much less than popular trackers from Sky-Watcher and iOptron, the SiFo unit (as it is labelled) offers the ability track the sky, avoiding any star trails. That alone would make it a bargain, and useful for nightscape and deep-sky photographers.
But it also has a function for panning horizontally, moving incrementally between exposures, thus the Move-Shoot-Move designation. The result is a time-lapse movie that pans along the horizon, but with each frame with the ground sharp, as the camera moves only between exposures, not during them.
Again, for $200 this is an excellent feature lacking in trackers like the Sky-Watcher Star Adventurer or iOptron SkyTracker. The Sky-Watcher Star Adventurer Mini does, however, offer both tracking and “move-shoot-move” time-lapse functions, but at a cost of $300 to $400 U.S., depending on accessories.
All these functions are provided in a unit that is light (weighing 700 grams with a tripod plate and the laser) and compact (taking up less space in your camera bag than most lenses). By comparison, the Star Adventurer Mini weighs 900 grams with the polar scope, while the original larger Star Adventurer is 1.4 kg, double the MSM’s weight.
Note, that the MSM’s advertised weight of 445 grams does not include the laser or a tripod plate, two items you need to use it. So 700 grams is a more realistic figure, still light, but not lighter than the competition by as much as you might be led to believe.
Nevertheless, the MSM’s small size and weight make it attractive for travel, especially for flights to remote sites. Construction is solid and all-metal. This is not a cheap plastic toy.
But does it work? Yes, but with several important caveats that might be a concern for some buyers.
What I Tested
I purchased the Basic Kit B package for $220 U.S., which includes a small case, a laser pointer and bracket for polar alignment (and with a small charger for the laser’s single 3.7-volt battery), and with the camera sync cable needed for time-lapse shooting.
I also purchased the new “button” model, not the older version that used a knob to set various tracking rates.
The ball head needed to go on top of the tracker is something you supply. The kit does come with two 3/8-inch stud bolts and a 3/8-to1/4-inch bushing adapter, for placing the tracker on tripods in the various mounting configurations I show below.
The first units were labelled as ‘SiFo,” but current units now carry the Gauda brand name. I’ll just call it the MSM.
I purchased the gear from the MSM website, and had my order fulfilled and shipped to me in Canada from China with no problems.
Tracking the Sky in Nightscapes
The attraction is its tracking function, allowing a camera to follow the sky and take exposures longer than any dictated by “500” or “NPF” Rules to avoid any star trailing.
Exposures can be a minute or more to record much more depth and detail in the Milky Way, though the ground will blur. But blending tracked sky exposures with untracked ground exposures gets around that, and with the MSM it’s easy to turn on and off the tracking motor, something not possible with the low-cost wind-up Mini Track from Omegon.
The illustrations and instructions (in a PDF well-hidden off the MSM Buy page) show the MSM mounted using the 1/4-20 bolt hole on the side of the unit opposite the LED-illuminated control panel. While this seems to be the preferredmethod, in the first unit I tested I found it produced serious mis-tracking problems.
With a Canon 6D MkII and 50mm f/1.4 lens (not a particularly heavy combination), the MSM’s gears would not engage and start tracking until after about 5 minutes. The first exposures were useless. This was also the case whenever I moved the camera to a new position to re-frame the scene or sky. Again, the first few minutes produced no or poor tracking until the gears finally engaged.
This would be a problem when taking tracked/untracked sets for nightscapes, as images need to be taken in quick succession. It’s also just plain annoying.
However, see the UPDATE at the end for the performance of a new Gauda-branded unit that was sent to me.
The solution was to mount the MSM using the 3/8-inch bolt hole on the back plate of the tracker, using the 1/4-20 adapter ring to allow it to attach to my tripod head. This still allowed me to tip the unit up to polar align it.
Tracking was now much more consistent, with only the first exposure usually badly trailed. But subsequent exposures all tracked, but with varying degrees of accuracy as I show below.
When used as a tracker, you need to control the camera’s exposure time with an external intervalometer you supply, to allow setting exposures over 30 seconds long.
The MSM offers a N and S setting, the latter for use in the Southern Hemisphere. A 1/2-speed setting turns the tracker at half the normal sidereal rate, useful for nightscapes as a compromise speed to provide some tracking while minimizing ground blurring.
For any tracker to track, its rotation axis has to be aimed at the Celestial Pole, near Polaris in the Northern Hemisphere, and near Sigma Octantis in the Southern Hemisphere.
I chose the laser pointer option for this, rather than the polar alignment scope. The laser attaches to the side of the MSM using a small screw-on metal bracket so that it points up along the axis of rotation, the polar axis.
The laser is labeled as a 1mw unit, but it is far brighter than any 1mw I’ve used. This does make it bright, allowing the beam to show up even when the sky is not dark. The battery is rechargeable and a small charger comes with the laser. Considering the laser is just a $15 option, it’s a bargain. But ….
UPDATE ADDED SEPTEMBER 1
Since I published the review, I have had the laser professionally tested, and it measured as having an output of 45 milliwatts. Yet it is labeled as being under 1 milliwatt. This is serious misrepresentation of the specs, done I can only assume to circumvent import restrictions. In Canada it is now illegal to import, own, or use any green laser over 5 milliwatts, a power level that would be sufficient for the intended use of polar aligning. 45mw is outright illegal.
So be warned, use of this laser will be illegal in some areas. And use of any green laser will be illegal close to airports, and outlawed entirely in some jurisdictions such as Australia, a fact the MSM website mentions.
The legal alternative is the optical polar alignment scope. I already have several of those, but my expectation that I could use one I had with the same bracket supplied with the laser were dashed by the fact that the bracket’s hole is too narrow to accept any of the other polar alignment scopes I have, which are all standard items. I you want a polar scope, buy theirs for $70.
However, if you can use it where you live, the laser works well enough, allowing you to aim the tracker at the Pole just by eye. For the wide lenses the tracker is intended to be used with, eyeball alignment proved good enough.
Just be very, very careful not to accidentally look down the beam. Seriously. It is far too easy to do by mistake, but doing so could damage your eye in moments.
Tracking the Sky in Deep-Sky Images
How well does the MSM actually track? In tests of the original SiFo unit I bought, and in sets of exposures with 35mm, 50mm, and 135mm lenses, and with the tracker mounted on the back, I found that 25% to 50% of the images showed mis-tracking. Gear errors still produced slightly trailed stars. This gear error shows itself more as you shoot with longer focal lengths.
The MSM is best for what it is advertised as — as a tracker for nightscapes with forgiving wide-angle lenses in the 14mm to 24mm range. With longer lenses, expect to throw away a good number of exposures as unusable. Take twice as many as you think you might need.
With a 135mm lens taking Milky Way closeups, more than half the shots were badly trailed. Really badly trailed. This is not from poor polar alignment, which produces a gradual drift of the frame, but from errors in the drive gears, and random errors at that, not periodic errors.
To be fair, this is often the case with other trackers as well. People always want to weight them down with heavy and demanding telephotos for deep-sky portraits, but that’s rarely a good idea with any tracker. They are best with wide lenses.
That said, I found the MSM’s error rate and amount to be much worse than with other trackers. With the Star Adventurer models and a 135mm lens for example, I can expect only 20% to 25% of the images to be trailed, and even then rarely as badly as what the MSM exhibited.
See the UPDATE at the end for the performance of the replacement Gauda-branded unit sent to me with the promise of much improved tracking accuracy.
Yes, enough shots worked to be usable, but it took using a fast f/2 lens to keep exposure times down to a minute to provide that yield. Users of slow f/5.6 kit-zoom lenses will struggle trying to take deep-sky images with the MSM.
In short, this is a low-cost tracker and it shows. It does work, but not as well as the higher-cost competitors. But restrict it to wide-angle lenses and you’ll be fine.
Panning the Ground
The other mode the MSM can be used in is as a time-lapse motion controller. Here you mount the MSM horizontally so the camera turns parallel to the horizon (or it can be mounted vertically for vertical panning, a mode I rarely use and did not test).
This is where the Move-Shoot-Move function comes in.
The supplied Sync cable goes from the camera’s flash hot shoe to the MSM’s camera jack. What happens is that when the camera finishes an exposure it sends a pulse to the MSM, which then quickly moves while the shutter is closed by the increment you set.
There is a choice of 4 speeds, marked in degrees-per-move: 0.05°, 0.2°, 0.5°, and 1.0°. For example, as the movie below shows, taking 360 frames at the 1° speed results in a complete 360° turn.
The MSM does the moving, but all the shutter speed control and intervals must be set using a separate intervalometer, either one built into the camera, or an outboard hardware unit. The MSM does not control the camera shutter. In fact, the camera controls the MSM.
Intervals should be set to be about 2 seconds longer than the shutter speed, to allow the MSM to perform its move and settle.
This connection between the MSM and camera worked very well. It is unconventional, but simple and effective.
Too Slow or Too Fast
The issue is the limited choice of move speeds. I found the 0.5° and 1° speeds much too fast for night use, except perhaps for special effects in urban cityscapes. Even in daytime use, when exposure times are very short, the results are dizzying, as I show below.
Even the 0.2°-per-move speed I feel is too fast for most nightscape work. Over the 300 exposures one typically takes for a time-lapse movie, that speed will turn the MSM (300 x 0.2°) = 60 degrees. That’s a lot of motion for 300 shots, which will usually be rendered out at 24 or 30 frames per second for a clip that lasts 10 to 12 seconds. The scene will turn a lot in that time.
On the other hand, the 0.05°-per-move setting is rather slow, producing a turn of (300 x 0.05°) = 15° during the 300 shots.
That works, but with all the motion controllers I’ve used — units that can run at whatever speed they need to get from the start point to the end point you set — I find a rate of about 0.1° per move is what works best for a movie that provides the right amount of motion. Not too slow. Not too fast. Just right.
UPDATE ADDED DECEMBER 21, 2019
From product photos on the MoveShootMove.com website now it appears that the tracker is now labeled MSM, as it should have been all along.
Most critically, perhaps in response to this review and my comments here, the time-lapse speeds have been changed to 0.05, 0.075, 0.1 and 0.125 degrees per move, adding the 0.1°/move speed I requested below and deleting the overly fast 0.5° and 1.0° speeds.
Plus it appears the new units have the panel labels printed the other way around so they are not upside down for most mounting situations.
I have not tested this new version, but these speeds sound much more usable for panning time-lapses. Bravo to MSM for listening!
Following the Sky in a Time-Lapse
The additional complication is trying to get the MSM to also turn at the right rate to follow the sky — for example, to keep the galaxy core in frame during the time-lapse clip. I think doing so produces one of the most effective time-lapse sequences.
But to do that with any device requires turning at a rate of 15° per hour, the rate the sky moves from east to west.
Because the MSM provides only set fixed speeds, the only way you have of controlling how much it moves over a given amount of time, such as an hour, is to vary the shutter speed.
I found that to get the MSM to follow the Milky Way in a time-lapse using the 0.05° rate and shooting 300 frames required shooting at a shutter speed of 12 seconds. No more, no less.
Do the Math
Where does that number come from?
At its rate of 0.05°/move, the MSM will turn 15° over 300 shots. The sky moves 15° in one hour, or 3600 seconds. So to fit 300 shots into 3600 seconds means each shot has to be no longer than (3600/300) = 12 seconds long.
The result works, as I show in the sampler movie.
But 12 seconds is a rather short shutter speed on a dark, moonless night with the Milky Way.
For properly exposed images you would need to shoot at very fast apertures (f/1.4 to f/2) and/or high and noisy ISO speeds. Neither are optimal. But they are forced upon you by the MSM’s restricted rates.
Using the faster 0.2° rate (of the original model) yields a turn of 60° over 300 shots. That’s four hours of sky motion. So each exposure now has to be 48 seconds long for the camera to follow the sky, four times longer because the drive rate is now four times faster.
A shutter speed of 48 seconds is a little too long in my opinion. Stars in each frame will trail. Plus a turn of 60° over 300 shots is quite a lot, producing a movie that turns too quickly.
By far the best speed for motion control time-lapses would be 0.1° per move. That would allow 24-second exposures to follow the sky, allowing a stop less in aperture or ISO speed. (DECEMBER 21 UPDATE: That speed seems to now be offered.)
Yes, having only a limited number of pre-wired speeds does make the MSM much easier to program than devices like the Star Adventurer Mini or SYRP Genie Mini that use wireless apps to set their functions. No question, the MSM is better suited to beginners who don’t want to fuss with lots of parameters.
As it is, getting a decent result requires some math and juggling of camera settings to make up for the MSM’s limited choices of speeds.
Time-Lapse Movie Examples
This compilation shows examples of daytime time-lapses taken at the fastest and dizzying 0.5° and 1.0° speeds, and night time-lapses taken at the slower speeds. The final clip is taken at 0.05°/move and with 12-second exposures, a combination that allowed the camera to nicely follow the Milky Way, albeit at a slow pace. Taking more than the 300 frames used here would have produced a clip that turned at the same rate, but lasted longer.
The MSM is powered off an internal rechargeable battery, which can be charged from any 5-volt charger you have from a mobile phone.
The MSM uses a USB-C jack for the power cable, but a USB-A to USB-C cord is supplied, handy as you might not have one if you don’t have other USB-C devices.
The battery lasted for half a dozen or more 300-shot time-lapses, enough to get you through at least 2 or 3 nights of shooting. However, my testing was done on warm summer nights. In winter battery life will be less.
While the built-in battery is handy, in the field should you find battery level low (the N and S switches blink as a warning) you can’t just swap in fresh batteries. Just remember to charge up before heading out. Alternatively, it can be charged from an external 5V battery pack such as used to prolong cell phone life.
The MSM does not offer, nor does it promise, any form of automated panorama shooting. This is where the device turns by, say, 15° to 45° between shots, to shoot the segments for a still-image panorama. More sophisticated motion controllers from SYRP and Edelkrone offer that function, including the ability to mate two devices for automated multi-tier panoramas.
Nor does the MSM offer the more advanced option of ramping speeds up and down at the start and end of a time-lapse. It moves at a constant rate throughout.
While some of the shortcomings could perhaps be fixed with a firmware update, there is no indication anywhere that its internal firmware can be updated through the USB-C port.
UPDATE ADDED OCTOBER 7, 2019
Since I published the review, MSM saw the initial test results and admitted that the earlier units like mine (ordered in June) exhibited large amounts of tracking error. They sent me a replacement unit, now branded with the Gauda label. According to MSM it contains a more powerful motor promised to improve tracking accuracy and making it possible to take images with lenses as long as 135mm.
I’m sorry to report it didn’t.
In tests with the 135mm lens the new, improved MSM still showed lots of tracking error, to the point that images taken with a lens as long as this were mostly unusable.
Tap or click on the images to download full-res versions.
The short movie above takes the full-frame images from the zenith set of 24 frames taken over 48 minutes and turns them into a little time-lapse. It shows how the mechanism of the MSM seems to be wobbling the camera around in a circle, creating the mis-tracking.
Comparison with the Star Adventurer
As a comparison, the next night I used a Sky-Watcher Star Adventurer (the full-size model not the Mini) to shoot the same fields in the northeast and overhead with the same 135mm lens and with the same ball-head, to ensure the ball-head was not at fault. Here are the results:
The Star Adventurer performed much better. Most images were well-tracked. Even on those frames that showed trailing, it was slight. The Star Adventurer is a unit you can use to take close-ups of deep-sky fields with telephoto lenses, if that’s your desire.
By contrast, the MSM is best used — indeed, I feel can only be used practically — with wide-angle lenses and with exposures under 2 minutes. Here’s a set taken with a 35mm lens, each for 2 minutes.
With the more forgiving 35mm lens, while more images worked, the success rate was still only 50%.
What I did not see with the new Gauda unit was the 5-minute delay before the gears meshed and tracking began. That issue has been resolved by the new, more powerful motor. The new Gauda model does start tracking right away.
But it is still prone to significant enough drive errors that stars are often trailed even with a 35mm lens (this was on a full-frame Canon 6D MkII).
UPDATED CONCLUSIONS (December 21, 2019)
The MSM tracker is low-cost, well-built, and compact for easy packing and travel. It performs its advertised functions well enough to allow users to get results, either tracked images of the Milky Way and constellations, or simple motion-control time-lapses.
But it is best used — indeed I would suggest can only be used — with wide-angle lenses for tracked Milky Way nightscapes. Even then, take more shots than you think you need to be sure enough are well-tracked and usable.
It can also be used for simple motion-control time-lapses, provided you do to the math to get it to turn by the amount you want, working around the too-slow or too-fast speeds. The new 0.1° per move speed (added in models as of December 2019) seems a reasonable rate for most time-lapses.
However, I think aspiring time-lapse photographers will soon outgrow the MSM’s limitations for motion-control sequences. But it can get you started.
If you really value its compactness and your budget is tight, the MSM will serve you well enough for tracked nightscape shooting with wide-angle lenses.
But if you wish to take close-ups of starfields and deep-sky objects with longer lenses, consider a unit like the Sky-Watcher Star Adventurer for its lower tracking errors. Or the Star Adventurer Mini for its better motion-control time-lapse functions.
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.
• 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
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
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.
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.
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.
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.
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
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.
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.
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
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.
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
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.
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.
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.
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.
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.
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
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.
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.
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
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
As most cameras do, the Z6 also has a “My Menu” page which you can also populate with favourite menu commands.
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.
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.
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.
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
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.
I was impressed with the Z6.
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.
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.
But what about lenses for the Sony? Here’s one ideal for astrophotography.
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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!
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
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
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.
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.
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.
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.
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 …
Functions in Layers are still limited. For example, there is no stacking and averaging for noise smoothing. Affinity Photo has those.
Filters, though abundant for artistic special effect “looks,” are limited in basic but essential functions. There is no Median filter, for one.
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.
The lack of support for third-party plug-ins means ON1 cannot work with essential time-lapse programs such as Timelapse Workflow or LRTimelapse.
Nightscapes: ON1 Photo RAW 2019 works acceptably well for nightscape still images:
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:
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.
As with the 2018 edition, you still cannot copy and paste masked local adjustments from image to image, limiting their use.
Exporting those images is slow.
Deep-Sky: ON1 is not a program I can recommend for deep-sky image processing:
Stars inevitably end up with unsightly sharpening haloes.
De-Bayering artifacts add blocky textures to the sky background.
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 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.
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.
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.
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
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
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
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).
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
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!
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.
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).
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.
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.
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
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.
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.
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.
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.
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
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 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’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
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.
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.
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.
• 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.
Here’s a short promo video, one that also opens the ebook as one of the embedded videos.
I originally published this ebook in 2014, then revised it in late 2016. Here’s what’s new in this 2018 Third Edition:
Updated equipment (cameras, lenses, filters, time-lapse gear) to reflect what’s current as of mid-2018. For example I added: the Revolve Camera slider; functions from the Canon 6D MkII; and information about the Sony a7III Mirrorless.
Updated the processing tutorials with current software: Photoshop CC2018, Lightroom Classic CC, Starry Landscape Stacker, TLDF, Timelapse Workflow, and LRTimelapse version 5.
Added tutorials on selected non-Adobe programs: DxO PhotoLab, ON1 Photo RAW, Affinity Photo, and the extensions Raya Pro 3 and Dr. Brown’s Services.
Added some 50 new topic pages, such as on memory cards and exposure blending.
In addition I’ve performed “housekeeping chores” such as:
Removing some embedded movies to reduce the file size and
Converting interactive diagrams into labeled images and
Flattening some of the interactive image galleries, all for facilitating conversion to PDFs for non-Apple platforms.
Improving the resolution of most tutorial screenshot images.
Improving many diagrams and updating many images.
Merging the chapter on Intervalometers into Chapter 1.
Plus I’ve added a section on lunar eclipses back in. Yay!
Here are screen shots of sample chapter content pages, to provide an idea of what the ebook contains and looks like.
All current owners of the older editions get the Third Edition update for free through the iBooks app (Mac or iPad, and also iPhone).
I hope you enjoy the new edition. Tell your friends! And do leave a rating or review at the iBooks sales page. Thanks!
And yes, for non-Apple people, a non-interactive PDF version for all other platforms (Windows and Android) is in production for later this year.
I put the new Sony a7III mirrorless camera through its paces for the features and functions we need to shoot the night sky.
Sony’s a7III camera has enjoyed rave reviews since its introduction earlier in 2018. Most tests focus on its superb auto exposure and auto focus capabilities that rival much more costly cameras, including Sony’s own a7rIII and a9.
For astrophotography, none of those auto functions are of any value. We shoot everything on manual. Indeed, the ease of manually focusing in Live View is a key function.
In my testing I compared the Sony a7III to two competitive DSLRs, the Canon 6D MkII and Nikon D750.
All three are “entry-level” full-frame cameras, with 24 to 26 megapixels and in a similar price league of $1,500 (Nikon) to 2,000 (Sony).
I tested a Sony a7III purchased locally. It was not supplied to me by Sony in return for an “influential” blog post.
I did this testing in preparation for the new third edition of my Nightscapes and Time-Lapse eBook, which includes information on Sony mirrorless cameras, as well as many, many other updates and additions!
NOTE:Click or Tap on most images to bring them up full-frame for inspection.
Mirrorless vs. DSLR
As with Sony’s other popular Alpha 7 and 9 series cameras, the new Alpha 7III is a full-frame mirrorless camera, a class of camera Canon and Nikon have yet to offer, though models are rumoured or promised.
In the meantime, Sony commands the full-frame mirrorless market.
As its name implies, a mirrorless camera lacks the reflex mirror of a digital single lens reflex camera that, in a DSLR, provides the light path for framing the scene though the optical viewfinder.
In a mirrorless, the camera remains in “live view” all the time, with the sensor always feeding a live image to either or both the rear LCD screen and electronic viewfinder (EVF). While you can look through and frame using the EVF as you would with a DSLR, you are looking at an electronic image from the sensor, not an optical image from the lens.
The advantage of purely electronic viewing is that the image you are previewing matches the image you’ll capture, at least for short exposures. The disadvantage is that full-time live view draws more power, with mirrorless cameras notorious for being battery hungry.
Other mirrorless advantages include:
Compact size and lighter weight, yet offering all the image quality of a full-frame DSLR.
The thinner body allows the use of lenses from any manufacturer, albeit requiring the right adapter, an additional expense.
Lenses developed natively for mirrorless models can be smaller and lighter. An example is the Laowa 15mm f/2 I used for some of the testing.
The design lends itself to video shooting, with many mirrorless cameras offering 4K as standard, while often in DSLRs only high-end models do.
More rapid-fire burst modes and quieter shutters are a plus for action and wedding photographers, though they are of limited value for astrophotography.
Points of Comparison
In testing the Sony a7III I ignored all the auto functions. Instead, I concentrated on those points I felt of most concern to astrophotographers, such as:
Effectiveness of Long Exposure Noise Reduction (LENR)
Quality of Raw files, such as sharpness of stars
Brightness of Live View for framing and focusing
Uniformity of sensor illumination
Compatibility for time-lapse imaging
Levels of luminance and chrominance noise were excellent and similar to – but surprisingly not better than – the Nikon D750.
The Star Eater is gone. Stars are not smoothed out in long exposures.
The Sony exhibited good – though not great – “ISO invariant” performance.
Dark frame subtraction using Long Exposure Noise Reduction removed most – but not all – hot pixels from thermal noise.
Live View Focusing and Framing
Live View was absolutely superb, though the outstanding Bright Monitoring function is as well-hidden as Sony could possibly make it.
Sensor Illumination Uniformity
The Sony showed some slight edge-of-frame shadowing from the mask in front of the sensor, as well as a weak purple amp glow.
• The a7III lacks any internal intervalometer or ability to add one via an app. But it is compatible with many external intervalometers and controllers.
• The a7III’s red sensitivity for recording H-Alpha-emitting nebulas was poor.
• It lacks the “light-frame” buffer offered by full-frame Canons that allows shooting several frames in quick succession even with LENR turned on.
The a7III offers 4K video and, at 24 frames-per-second, is full-frame. Shutter speeds can be as slow as 1/4-second, allowing real-time aurora shooting at reasonable ISO speeds.
Shooting typical 400-frame time-lapses used about 40% of the battery capacity, similar to the other DSLRs.
The Sony a7III is a superb camera for still and time-lapse nightscape shooting, and excellent for real-time aurora videos. It is good, though not great, for long-exposure deep-sky imaging.
The Sony a7III uses a sensor that is “Backside Illuminated,” a feature that promises to improve low-light performance and reduce noise.
I saw no great benefit from the BSI sensor. Noise at typical astrophoto ISO speeds – 800 to 6400 – were about equal to the four-year-old Nikon D750.
That was a bit surprising. I expected the new BSI-equipped Sony to better the Nikon by about a stop. It did not. This emphasizes just how good the Nikon D750 is.
Nevertheless, noise performance of the Sony a7III was still excellent, with both the Sony and Nikon handily outperforming the Canon 6D MkII, with its slightly smaller pixels, by about a stop in noise levels.
NOTE: I performed all Raw developing with Adobe Camera Raw v10.3. It is possible some of the artifacts I saw are due to ACR not handling the a7III’s .ARW files as well as it should. But to develop all the images from Sony, Nikon, and Canon equally for comparisons, ACR is the best choice.
Both the Sony and Nikon use sensor and signal path designs that are “ISO invariant.” As a result, images shot underexposed at slower ISOs, then boosted in exposure later in processing look identical to properly exposed high-ISO images. Well, almost.
The Sony still showed some discoloration artifacts and added noise when boosting images by +4 EV that the Nikon did not. Even with uncompressed Raws, the Sony was not quite as ISO invariant as the Nikon, though the difference shows up only under extreme push-processing of badly underexposed frames.
Plus, the Sony was far better than the Canon 6D MkII’s “ISO variant” sensor. Canon really needs to improve their sensors to keep in the game.
Compressed vs. Uncompressed
The Sony a7III offers a choice of shooting Uncompressed or Compressed Raw files. Uncompressed Raws are 47 Mb in size; Compressed Raws are 24 Mb.
In well-exposed images, I saw little difference in image quality.
But the dark shadows in underexposed nightscapes withstood shadow recovery better in the uncompressed files. Compressed files showed more noise and magenta discoloration in the shadows.
It is not clear if Sony’s compressed Raws are 12-bit vs. 14-bit for uncompressed files.
Nevertheless, for the demands of nightscape and deep-sky shooting and processing, I suggest shooting Uncompressed Raws. Use Compressed only if you plan to take lots of time-lapse frames and need to conserve memory card space on extended shoots.
Star Eater (Updated June 3, 2018)
Over the last year or so, firmware updates from Sony introduced a much-publicized penchant for Sony Alphas to “eat” stars even in Raw files, apparently due to an internal noise reduction or anti-aliasing routine users could not turn off. Stars were smoothed away along with the noise in exposures longer than 3.2 seconds in some Sony cameras (longer than 30 seconds in others).
I feel that in the a7III the Star Eater has been largely vanquished.
As the images below show, there is a very slight one-pixel-level softening that kicks in at 4 seconds and longer but it did not eat or wipe out stars. Stars are visible to the same limiting magnitude and close double stars are just as well resolved across all exposures. Indeed, at slower ISOs and longer exposures, more stars are visible.
I saw none of the extreme effects reported by others with other Sonys, where masses of faint stars disappeared or turned into multi-colored blotches.
I did not see any significant “star eating” in any long exposures even up to the 4 minutes I used for some deep-sky shots. In images taken at the same time with other cameras not accused of star eating, the Sony showed just as many faint stars as the competitors. Long exposures showed just as many stars as did short exposures.
This was true whether I was shooting compressed or uncompressed Raws, with or without Long Exposure Noise Reduction. Neither compression nor LENR invoked “star eating.”
LENR Dark frames
For elimination of hot pixels from thermal noise I prefer to use Long Exposure Noise Reduction when possible for nightscape and deep-sky images, especially on warm summer nights.
Exceptions are images taken for star trail stacking and for time-lapses, images that must be taken in quick succession, with minimal time gap between frames.
Turning on LENR did eliminate most hot pixels in long exposures, but not all. A few remained. Also, when boosting the exposure a lot in processing, the images taken with LENR on showed more shot and read noise than non-LENR frames.
The dark frame the camera was taking and subtracting was actually adding some noise, perhaps due to a temperature difference. The cause is not clear.
Sony advises that when using LENR Raw images are recorded with only 12-bit depth, not 14-bit. This might be a contributing factor. Yet frames taken with LENR on were the same 47 Mb size as normal uncompressed frames.
For those who think this is normal for LENR use, the Nikon D750 shows nothing like this – frames taken with LENR on are free of all hot pixels and do not show more shot or read noise, nor deterioration of shadow detail from lower bit depths.
However, I emphasize that the noise increase from using LENR with the Sony was visible only when severely boosting underexposed images in processing.
In most shooting situations, I found using LENR provided the overriding positive benefit of reducing hot pixels. It just needs to be better, Sony!
How evenly an image is illuminated is a common factor when testing lenses.
But astrophotography, which often requires extreme contrast boosts, reveals non-uniform illumination of the sensor itself, regardless of the optics, originating from hardware elements in front of the sensor casting shadows onto the sensor.
This is most noticeable – indeed usually only noticeable – when shooting deep-sky targets though telescopes.
With DSLRs it is the raised mirror which often casts a shadow, produced a dark vignetted band along the bottom of the frame. Its extent varies from camera model to model.
With a mirrorless camera the sensor is not set far back in a mirror box, as it is in a DSLR. As such, I would have expected a more uniformly illuminated sensor.
Instead, I saw a slight shadowing at the top and bottom edges but just at the corners. This is from a thin metal mask in front of the sensor. It intrudes into the light path ever so slightly. It shouldn’t.
This is an annoying flaw, though applying “flat fields” or ad hoc local adjustments should eliminate this. But that’s a nuisance to do, and should not be necessary with a mirrorless camera.
Worse is that long deep-sky exposures at high ISOs also exhibited a faint purple glow at the left edge, perhaps from heat from nearby electronics, a so-called “amp glow.” Or I’ve read where this is from an internal infrared source near the sensor.
Taking a dark frame with LENR did not eliminate this, and it should, demonstrating again that for whatever reason in the a7III LENR is not as effective as it should be.
I have not seen such “amp” glows in cameras (at least in the DSLRs I’ve used) for a number of years, so seeing it in the new Sony a7III was another surprise.
This would be much tougher to eliminate in deep-sky images where the extreme contrast boosts we typically apply to images of nebulas and galaxies will accentuate any odd glows.
One supplier of filter-modified cameras, Spencer’s Camera, also refuses to modify Sonys, because this glow renders them poor choices for filter modification, for those wanting cameras with deeper red sensitivity.
When shooting deep-sky objects, particularly red nebulas, we like a camera to have a less aggressive infrared cutoff filter, to pick up as much of the deep red Hydrogen-Alpha emission line as possible.
The Sony showed poor deep-red sensitivity, though not unlike other cameras. It was a little worse than the stock Canon 6D MkII.
This isn’t a huge detriment, as anyone who really wants to go after deep nebulosity must use a “filter-modified” camera anyway.
Canon and Nikon both offered factory modified cameras at one time, notably the Canon 60Da and Nikon D810a. Sony doesn’t have an “a” model mirrorless.
To get the most out of the Sony for deep-sky imaging you would have to have it modified by a third-party, though the amp glow described above makes it a poor choice for modification.
Live View Focusing and Framing
Up to now my report on the Sony a7III hasn’t shown as glowing a performance as all the YouTube reviews would have you believe.
But Live Focus is where the a7III really stands out. I love it!
In Live View it is possible to make the image so bright you can actually see the Milky Way live on screen! Wow! This makes it so easy to frame nightscapes and deep-sky fields.
But this special “Bright Monitoring” mode is as well hidden as Sony could make it. Unless you actually read the full-length 642-page PDF manual (you have to download it), you won’t know about it. Bright Monitoring does not appear in any of the in-camera menus you can scroll through, so you won’t stumble across it.
Instead, you have to go to the Camera Settings 2 page, then select Still Image–Custom Key. In the menu options that appear you can now scroll to one called Bright Monitoring. Surprise! Assign it to one of the hardware Custom C buttons. I put it on C2, making it easy to call up when needed.
The other Live View function that works well, but also needs assigning to a C button is the Camera Settings 1 > Focus Magnifier. I put this on C1. It magnifies the Live View by 5.9x or 11.7x, allowing for precise manual focusing on a star.
Two other functions are useful for Live View:
Camera Settings 2 > Live View Display > Setting Effect ON. This allows the Live View image to reflect the camera settings in use, better simulating the actual exposure, even without Bright Monitoring on.
Camera Settings 1 > Peaking Setting. Turning this ON superimposes a shimmering effect on parts of an image judged in focus. This might be an aid, or an annoyance. Try it.
In all, the Sony provides superb, if well-hidden, Live View options that make accurately framing and focusing a nightscape or time-lapse scene a joy.
Great Features for Astrophotography
Here are some other Sony a7III features I found of value for astrophotography, and for operating the camera at night.
Tilting LCD Screen
Like the Nikon D750, the Sony’s screen tilts vertically up and down, great for use when on a telescope, or on any tripod when aimed up at the sky. As photographers age, this becomes a more essential feature!
The four C buttons can be programmed for oft-used functions, making them easy to access at night. Standard functions such as ISO and Drive Mode are easy to get at on the thumb wheel, unlike the Nikon D750 where I am forever hunting for the ISO or Focus Zoom buttons, or the Canon 6D MkII which successfully hides the Focus Zoom and Playback buttons at night.
In new models, Sony now offers the option of a final “My Menu” page which you can populate with often-used functions from the other 35 pages of menu commands!
Adaptability to Many Lenses
Using the right lens adapter (I use one from Metabones), it is possible to use lenses with mounts made for Canon, Nikon, Sigma and others. Plus there are an increasing number of lenses from third parties offered with native Sony E-mounts. This is good news, as astrophotography requires fast, high-quality lenses, and the Sony allows more choices.
Lighter Weight / Smaller Size
The compact a7III body weighs a measured 750 grams, vs. 900 grams each for the Nikon D750 and Canon 6D MkII. The lower weight can be helpful for use on lightweight telescopes, on small motion control devices, and for simply keeping weight and bulk down when traveling.
Dual Card Slots
Not essential, but having two card slots is very helpful, for backup, for handling overflows from very long time-lapse shoots, or assigning them for stills vs. movies, or Raws vs. JPGs. Only Slot 1 will work with the fastest UHS II cards that are needed for recording the highest quality 4K video.
It is possible to power the camera though the USB port (indeed that’s how you charge the battery, as no separate battery charger is supplied as standard, a deficiency). This might be useful for long shoots, though likely as not that same USB port will be needed for an intervalometer or motion control device. But if the Sony had a built-in intervalometer…!
To reduce battery drain it is possible to turn off the EVF completely – I find I never use it at night – and to turn off the LCD display when shooting, though the latter is an option you have to activate to add to the Display button’s various modes.
The downside is that when shooting is underway you get no reassuring indication anything is happening, except for a brief LED flash when an image is written to a card.
Electronic Front Curtain Shutter
Most DSLRs do not offer this, but the Sony’s option of an electronic front curtain shutter and the additional Silent Shooting mode completely eliminates vibration, useful for some high-magnification shooting through telephotos and telescopes.
What’s Missing for Astrophotography
Intervalometer — NOW INCLUDED! UPDATE: In April 2019 Sony issued a v3 Firmware update for the a7III which added an internal intervalometer. I’ve used this new function and it works very well.
I had originally remarked that this useful function was missing. But no more! Thank you Sony!
While a built-in intervalometer is not essential, I find I often do use the Canon and Nikon in-camera intervalometers for simple shoots. So it is great to have one available on the Sony. However, like other brands’ internal intervalometers Sony’s is good only for exposures up to 30 seconds long.
Bulb Timer or Long Exposures
However, while the Sony has a Bulb setting there is no Bulb Timer as there is with the Canon. The Bulb Timer would allow setting long Bulb exposures of any length in the camera.
Instead, for any exposures over 30 seconds long (or time-lapses with >30-second-long frames) the Sony must be used with an external Intervalometer. I use a $50 Vello unit, and it works very well. It controls the Sony through the camera’s Multi USB port.
In-Camera Image Stacking
Also missing, and present on most new Canons, are Multiple Exposure modes for in-camera stacking of exposures in a Brighten mode (for star trails) or Averaging mode (for noise smoothing).
Yes, this can all be done later in processing, but having the camera do the stacking can often be convenient, and great for beginners, as long as they understand what those functions do, or even that they exist!
When using its internal intervalometer, the Nikon D750 has an excellent Exposure Smoothing option. This does a fine job smoothing frame-to-frame flickering in time-lapses, something the Canon cannot do. Nor the Sony, as it has no intervalometer at all.
Light Frame Buffer in LENR
This feature is little known and utilized, and only Canon full-frame cameras offer it. Turn on LENR and it is possible to shoot three (with the 6D MkII) or four (with the 6D) Raw images in quick succession even with LENR turned on. The Canon 5D series also has this.
The dark frame kicks in and locks up the camera only after the series of “light frames” are taken. This is wonderful for taking a set of noise-reduced deep-sky images for later stacking. Nikons don’t have this, not even the D810a, and not Sonys.
The Sony’s buttons are not illuminated. While these might add glows to long exposure images, if they could be designed not to do that (i.e. they turn off during exposures), lit buttons would be very handy at night.
Limited Touch Screen Functions
An alternative would be an LCD screen that was touch sensitive. The Sony a7III’s screen is, but only to select an area for auto focus or zooming up an image in playback. The Canon 6D MkII has a fully functional touch screen which can be, quite literally, handy at night.
Here’s another area where the new Sony a7III really shines.
It offers 4K (or more precisely UltraHD) video recording for videos of 3840 x 2160 pixels. (True 4K is actually 4096 x 2160 pixels.)
With a fast enough UHS-II Class card it can record 4K video up to 30 frames per second and at a bit rate of either 60 or 100 Mbps.
At 24 fps videos are full-frame with no cropping. Hurray! You can take full advantage of wide-angle lenses, great for auroras. At 30 fps, 4K videos are cropped with a 1.2x crop factor.
In Movie Mode ISO speeds go up to ISO 102,400, but are pretty noisy, if unusable at such speeds.
But when shooting aurora videos I found, to my surprise, I could “drag” the shutter speeds as slow as 1/4-second, fully 4 stops better than the Nikon’s slowest shutter speed of 1/60 second in Full HD, and 3 stops better than the Canon’s slowest movie shutter of 1/30 second.
Coupled with a fast f/1.4 to f/2 lens, the slow shutter speed allows real-time aurora shooting at “only” ISO 6400 to 12,800, for quite acceptable levels of noise. I am very impressed!
Real-time video of auroras is not possible with anything like this quality with the Nikon (I’ve used it often), and absolutely not with the Canon. And neither are 4K.
Is the a7III as good for low-light video as the Sony a7s models, with their larger 8.5-micron pixels?
I would assume not, but not having an a7s (either Mark I or II) to test I can’t say for sure. But the a7III should do the job for bright auroras, the ones with rapid motion worth recording with video, plus offer 24 megapixels for high-quality stills of all sky subjects.
I think it’s a great camera for both astrophoto stills and video.
An example is in a 4K video I shot on May 6, 2018 of an usual aurora known as “STEVE.”
Steve Aurora – May 6, 2018 (4K) from Alan Dyer on Vimeo.
For another example of using the Sony a7III for recording real-time video of the night sky see this video of the aurora shot from Norway in March 2019.
The Northern Lights At Sea from Alan Dyer on Vimeo.
I found the a7III would use up about about 40% of the battery capacity in a typical 400-frame time-lapse on mild spring nights, with 30-second exposures. This is with the EVF and rear LCD Display OFF, and the camera in Airplane mode to turn off wireless functions to further conserve battery power. I was using the wired Vello intervalometer.
This is excellent performance on par with the DSLRs I use. At last, we have a mirrorless camera that not only doesn’t eat stars, it also does not eat batteries!
One battery can get you through a night of shooting, though performance will inevitably decline in winter, as with all cameras.
Lens and Telescope Compatibility
As versatile as a mirrorless camera is for lens choice, making use of that versatility requires buying the right lens adapter(s). They can cost anywhere from $100 to $400. The lowest cost units just adapt the lens mechanically; the more costly units also transfer lens data and allow auto focusing with varying degrees of compatibility.
For use on telescopes, the simple adapters will be sufficient, and necessary as many telescope-to-camera adapters and field flatteners are optimized for the longer lens flange-to-sensor distance of a DSLR. Even if you could get a mirrorless camera to focus without a lens adapter to add the extra spacing, the image quality across the field might be compromised on many telescopes.
I used the Metabones Canon-to-Sony adapter when attaching the Sony to my telescopes using my existing Canon telescope adapters. Image quality was just fine.
Time-Lapse Controller Compatibility
Due to limitations set by Sony, controlling one of their cameras with an external controller can be problematic.
Devices that trigger only the shutter should be fine. That includes simple intervalometers like the Vello, the Syrp Genie Mini panning unit, and the Dynamic Perception and Rhino sliders, to name devices I use. However, all will need the right camera control cable, available from suppliers like B&H.
And, as I found, the Sony might need to be placed into Continuous shooting mode to have the shutter fire with every trigger pulse from the motion controller. When used with the Genie Mini (below) the Sony fired at only every other pulse if it was in Single shot mode, an oddity of Sony’s firmware.
Some time-lapse controllers are able to connect to a camera through its USB port and then adjust the ISO and aperture as well, for ramped “holy grail” sunset-to-Milky Way sequences.
In conclusion, here’s my summary recommendations for the three competitive cameras, rating them from Poor, to Fair, to Good, to Excellent.
SONY: I deducted marks from the Sony a7III for deep-sky imaging for its lack of a light frame buffer, poor red sensitivity, odd LENR performance, and purple amp glow not seen on the other cameras and that dark frames did not eliminate.
However, I did not consider “star eating” to be a negative factor, as the Sony showed just as many stars and as well-resolved as did the competitors, and what more could you ask for?
I rate the Sony excellent for nightscape imaging and for real-time aurora videos. I list it as just “good” for time-lapse work only because it will not be fully compatible with some motion controllers and rampers. So beware!
NIKON: I deducted points for real-time video of auroras – the D750 can do them but is pretty noisy with the high ISOs needed. Its red sensitivity is not bad, but its lack of a light frame buffer results a less productive imaging cycle when using LENR on deep-sky shooting.
I know … people shoot dark frames separately for subtracting later in processing. However, I’ve found these post-shoot darks rarely work well, as the dark frames are not at the same temperature as the light frames, and often add noise or dark holes.
CANON: The 6D MkII’s lack of an ISO invariant sensor rears its ugly head in underexposed shadows in dark-sky nightscapes. I like its image stacking options, which can help alleviate the noise and artifacts in still images, but aren’t practical for time-lapses. Thus my Good rating for nightscapes but Fair rating for time-lapses. (See my test at https://amazingsky.net/2017/08/09/testing-the-canon-6d-mark-ii-for-nightscapes/)
While the 6D MkII has HD video, it is incapable of any low-light video work.
And its light-frame buffer is great for minimizing shooting time for a series of deep-sky images with in-camera LENR dark frames, which I find are the best for minimizing thermal noise. Give me a Canon full-frame any day for prime-focus deep-sky shooting.
It’s just a pity the 6D MkII has only a 3-frame buffer when using LENR. Really Canon? The 2008-vintage 5D MkII had a 5-frame buffer! Your cameras are getting worse for astrophotography while Sony’s are getting better.
CANON 6D Mk II
Real-Time Video (Auroras)
Wide-field Deep Sky
Telescopic Deep Sky
I trust you’ll find the review of value. Thanks for reading!
ADDENDUM as of JUNE 6, 2018
Since publishing the first results a number of people commented with suggestions for further testing, to check claims that:
The Sony would perform better for noise under dark sky conditions, at high ISOs, rather than the moonlit scene above. OK, let’s try that.
The Sony would perform better in an ISO Invariancy “face-off” if its ISOs were kept above 640, to keep all the images within the Sony’s upper ISO range of its dual-gain sensor design, with two ranges (100 to 400, and 640 on up). Fair enough.
What little “star-eater” effect I saw might be mitigated by shooting on Continuous drive mode or by firing the shutter with an external timer. That’s worth a check, too.
For the additional tests, I shot all images within a 3-hour span on the night of June 5/6, using the Sony a7III, Nikon D750, and Canon 6D MkII, with the respective lenses: the Laowa 15mm lens at f/2, the Sigma 14mm Art at f/2, and the Rokinon 14mm SP at f/2.5.
The cameras were on a Star Adventurer Mini tracker to keep stars pinpoints, though the ground blurred in the longer exposures.
DARK SKY NOISE TEST
I show only the Sony and Nikon compared here, shot at the common range of ISOs used for nightscape shooting, 800 to 12800. All images are equally well exposed. The inset image at right in Photoshop shows the scene, the Milky Way above dark trees in my backyard!
To the eye, the Sony and Nikon look very similar for noise levels, just as in the moonlit scene. Both are very good – indeed, among the best performing cameras for high-ISO noise levels. But the Sony, being four years newer than the Nikon, is not better.
BUT … what the Sony did exhibit was better details in the shadows than the Nikon.
And this was with equal processing and no application of Shadow Recovery. This is where the Sony’s Backside Illuminated sensor with presumably higher quantum efficiency in gathering photons might be providing the advantage. With its good shadow details, you have to apply less shadow recovery in post-processing, which does keep noise down. So points to Sony here.
I did put all the high ISO images through the classic noise reduction program Noise Ninja to measure total Luminance and Chrominance noise, and included the Canon 6D MkII’s images.
The resulting values and graph show the Sony actually measured worse for noise than the Nikon at each high ISO speed, 3200 to 12800, though with both performing much better than the Canon.
The higher noise of the Canon is visually obvious, but I’d say the Sony a7III and Nikon D750 are pretty equal visually for noise, despite the numbers.
DARK SKY ISO INVARIANCY
Again, here I show only the Sony and Nikon, the two “ISO invariant” cameras. The correct exposure for the scene was 30 seconds at ISO 6400 and f/2. The images shown here were shot at lower ISOs to underexposure the dark scene by 2 to 4 stops or EV. Those underexposed images were then boosted later in processing (in Adobe Camera Raw) by the required Exposure Value to equalize the image brightness.
Contrary to expectations, the Sony did not show any great loss in image quality as it crossed the ISO 640 boundary into its lower ISO range. But the Nikon did show more image artifacts in the “odd-numbered” ISOs of 640 and 500. In this test, the Nikon did not perform as well as the Sony for ISO invariancy. Go figure!
Again, the differences are in images vastly underexposed. And both cameras performed much better than the ISO “variant” Canon in this test.
STAR EATER REVISITED
I shot images over a wide-range of exposures, from 2 seconds to 2 minutes, but show only the ones covering the 2-second to 4-second range, where the “star-eater” anti-aliasing or noise smoothing applied by Sony kicks in (above 3.2 seconds it seems).
I shot with the Sony a7III on Single shot drive mode, on Continuous Low drive mode (with the camera controlling the shutter speed in both cases), and a set with the Sony on Bulb and the shutter speed set by an external Vello intervalometer.
This is really pixel peeping at 400%. In Single drive mode, stars and noise soften ever so slightly at 4 seconds and higher. In Continuous mode, I think the effect is still there but maybe a little less. In shots on Bulb controlled by the External Timer, maybe the stars at 4 seconds are a little sharper still. But this is a tough call. To me, the star eater effect on the Sony a7III is a non-issue. It may be more serious on other Sony alphas.
DE-BAYERING STAR ARTIFACTS
An issue that, to me, has a more serious effect on star quality is the propensity of the Sony, and to some extent the Nikon, to render tiny stars as brightly colored points, unrealistically so. In particular, many stars look green, from the dominance of green-filtered photosites on Bayer-array sensors.
Here I compare all three cameras for this effect in two-minute tracked exposures taken with Long Exposure Noise Reduction (i.e. in-camera dark frame subtraction) off and on.
The Sony shows a lot of green stars with or without LENR. The Nikon seems to discolor stars only when LENR is applied. Why would that be? The Canon is free of any such issue – stars are naturally colored whether LENR dark frames are applied or not.
This is all with Raws developed with Adobe Camera Raw.
When opening the same Raws in other programs (ON1 Photo RAW, Affinity Photo, DxO PhotoLab, and Raw Therapee) the results can be quite different, with stars often rendered with fringes of hot, colored pixels. Or rendered with little or no color at all. Raw Therapee offers a choice of de-Bayering, or “de-mosaic,” routines, and each produces different looking stars, and none look great! Certainly not as good as the Canon rendered with Camera Raw.
What’s going on here is a mystery – it’s a combination of the cameras’ unique Raw file formats, anti-alias filter in front of the sensor (or lack thereof in the Sony), and the de-Bayering routines of all the many Raw developers wrestling with the task of rendering stars that occupy only a few pixels. It’s unfair to blame just the hardware or the software.
But this test re-emphasized my thoughts that Canon DSLRs remain the best for long-exposure deep-sky imaging where you can give images as much exposure time as they need, while the ISO invariant Sony and Nikons exceed at nightscape shooting where exposures are often limited and plagued by dark shadows and noise.
To Adobe or not to Adobe. That is the question many photographers are asking with the spate of new image processing programs vying to “kill Photoshop.”
I tested more than ten contenders as alternatives to Adobe’s image processing software, evaluating them ONLY for the specialized task of editing demanding nightscape images taken under the Milky Way, both for single still images and for time-lapses of the moving sky. I did not test these programs for other more “normal” types of images.
Also, please keep in mind, I am a Mac user and tested only programs available for MacOS, though many are also available for Windows. I’ve indicated these.
But I did not test any Windows-only programs. So sorry, fans of Paintshop Pro (though see my note at the end), Photoline, Picture Window Pro, or Xara Photo & Graphic Designer. They’re not here. Even so, I think you will find there’s plenty to pick from!
If you are hoping there’s a clear winner in the battle against Adobe, one program I can say does it all and for less cost and commitment, I didn’t find one.
However, a number of contenders offer excellent features and might replace at least one member of Adobe’s image processing suite.
For example, only four of these programs can truly serve as a layer-based editing program replacing Photoshop.
The others are better described as Adobe Lightroom competitors – programs that can catalog image libraries and develop raw image files, with some offering adjustment layers for correcting color, contrast, etc. But as with Lightroom, layering of images – to stack, composite, and mask them – is beyond their ability.
For processing time-lapse sequences, however, we don’t need, nor can we use, the ability to layer and mask several images into one composite.
What we need for time-lapses is to:
Develop a single key raw file, then …
Copy its settings to the hundreds of other raw files in the time-lapse set, then …
Export that folder of raw images to “intermediate JPGs” for assembly into a movie.
Even so, not all these contenders are up to the task.
Here are the image processing programs I looked at. Costs are in U.S. dollars. Most have free trial copies available.
The Champion from Adobe
Adobe Camera Raw (ACR), Photoshop, Bridge, and Lightroom, the standards to measure others by
Cost: $10 a month by subscription, includes ACR, Photoshop, Bridge, and Lightroom
Adobe Camera Raw (ACR) is the raw development plug-in that comes with Photoshop and Adobe Bridge, Adobe’s image browsing application that accompanies Photoshop. Camera Raw is equivalent to the Develop module in Lightroom, Adobe’s cataloguing and raw processing software. Camera Raw and Lightroom have identical processing functions and can produce identical results.
Photoshop and Lightroom complement each other and are now available together, but only by monthly subscription through Adobe’s Creative Cloud service, at $10/month. Though $120 for a year is not far off the cost of purchasing many of these other programs and perhaps upgrading them annually, many photographers prefer to purchase their software and not subscribe to it.
Thus the popularity of these alternative programs. Most offered major updates in late 2017.
My question is, how well do they work? Are any serious contenders to replace Photoshop or Lightroom?
Lightroom Contenders: Five Raw Developers
ACDSee Photo Studio (current as of late 2017)
Cost: $60 to $100, depending on version, upgrades $40 to $60.
I tested the single MacOS version. Windows users have a choice of either a Standard or Professional version. Only the Pro version offers the full suite of raw development features, in addition to cataloging functions. The MacOS version resembles the Windows Pro version.
Capture One v11 (late 2017 release)
Cost: $299, and $120 for major upgrades, or by subscription for $180/year
As of version 11 this powerful raw developer and cataloguing program offers “Layers.” But these are only for applying local adjustments to masked areas of an image. You cannot layer different images. So Capture One cannot be used like Photoshop, to stack and composite images. It is a Lightroom replacement only, but a very good one indeed.
The ELITE version of what DxO now calls “PhotoLab” offers DxO’s superb PRIME noise reduction and excellent ClearView contrast enhancement feature. While it has an image browser, PhotoLab does not create a catalog, so this isn’t a full Lightroom replacement, but it is a superb raw developer. DxO also recently acquired the excellent Nik Collection of image processing plug-ins, so we can expect some interesting additions and features.
This free open source program has been created and is supported by a loyal community of programmers. It offers a bewildering blizzard of panels and controls, among them the ability to apply dark frames and flat field images, features unique among any raw developer and aimed specifically at astrophotographers. Yes, it’s free, but the learning curve is precipitous.
Photoshop Contenders: Four Raw Developers with Layering/Compositing
These programs can not only develop at least single raw images, if not many, but also offer some degree of image layering, compositing, and masking like Photoshop.
However, only ON1 Photo RAW can do that and also catalog/browse images as Lightroom can. Neither Affinity, Luminar, or Pixelmator offer a library catalog like Lightroom, nor even a file browsing function such as Adobe Bridge, serious deficiencies I feel.
This is the lowest cost raw developer and layer-based program on offer here, and has some impressive features, such as stacking images, HDR blending, and panorama stitching. However, it lacks any library or cataloguing function, so this is not a Lightroom replacement, but it could replace Photoshop.
Macphun has changed their name to Skylum and now makes their fine Luminar program for both Mac and Windows. While adding special effects is its forte, Luminar does work well both as a raw developer and layer-based editor. But like Affinity, it has no cataloguing feature. It cannot replace Lightroom.
Of all the contenders tested here, this is the only program that can truly replace both Lightroom and Photoshop, in that ON1 has cataloguing, raw developing, and image layering and masking abilities. In fact, ON1 allows you to migrate your Lightroom catalog into its format. However, ON1’s cost to buy and maintain is similar to Adobe’s Creative Cloud Photo subscription plan. It’s just that ON1’s license is “perpetual.”
NOTE: Windows users might find Corel’s Paintshop Pro 2018 a good “do-it-all” solution – I tested only Corel’s raw developer program Aftershot Pro, which Paintshop Pro uses.
The “Pro” version of Pixelmator was introduced in November 2017. It has an innovative interface and many fine features, and it allows layering and masking of multiple images. However, it lacks some of the key functions (listed below) needed for nightscape and time-lapse work. Touted as a Photoshop replacement, it isn’t there yet.
This is the image I threw at all the programs, a 2-minute exposure of the Milky Way taken at Writing-on-Stone Provincial Park in southern Alberta in late July 2017.
NOTE: Click/tap on any of the screen shots to bring them up full screen so you can inspect and save them.
The lens was the Sigma 20mm Art lens at f/2 and the camera the Nikon D750 at ISO 1600.
Thus the ground is blurred. Keep that in mind, as it will always look fuzzy in the comparison images. But it does show up noise well, including hot pixels. This image of the sky is designed to be composited with one taken without the tracker turning, to keep the ground sharp.
Above is the image after development in Adobe Camera Raw (ACR), using sliders under its Basic, Tone Curve, Detail, HSL, Lens Corrections, and Effects tabs. Plus I added a “local adjustment” gradient to darken the sky at the top of the frame. I judged programs on how well they could match or beat this result.
Above is the same image developed in Adobe Lightroom, to demonstrate how it can achieve identical results to Camera Raw, because at heart it is Camera Raw.
I have assumed a workflow that starts with raw image files from the camera, not JPGs, for high-quality results.
And I have assumed the goal of making that raw image look as good as possible at the raw stage, before it goes to Photoshop or some other bit-mapped editor. That’s an essential workflow for time-lapse shooting, if not still-image nightscapes.
However, I made no attempt to evaluate all these programs for a wide range of photo applications. That would be a monumental task!
Nor, in the few programs capable of the task, did I test image layering. My focus was on developing a raw image. As such, I did not test the popular free program GIMP, as it does not open raw files. GIMP users must turn to one of the raw developers here as a first stage.
If you are curious how a program might perform for your purposes and on your photos, then why not test drive a trial copy?
Instead, my focus was on these programs’ abilities to produce great looking results when processing one type of image: my typical Milky Way nightscape, below.
Such an image is a challenge because…
The subject is inherently low in contrast, with the sky often much brighter than the ground. The sky needs much more contrast applied, but without blocking up the shadows in the ground.
The sky is often plagued by off-color tints from artificial and natural sky glows.
The ground is dark, perhaps lit only by starlight. Bringing out landscape details requires excellent shadow recovery.
Key to success is superb noise reduction. Images are shot at high ISOs and are rife with noise in the shadows. We need to reduce noise without losing stars or sharpness in the landscape.
I focused on being able to make one image look as good as possible as a raw file, before bringing it into Photoshop or a layer-based editor – though that’s where it will usually end up, for stacking and compositing, as per the final result shown at the end.
I then looked at each program’s ability to transfer that one key image’s settings over to what could be hundreds of other images taken that night, either for stacking into star trails or for assembling into a time-lapse movie.
None of the programs I tested ticked all the boxes in providing all the functions and image quality of the Adobe products.
But here’s a summary of my recommendations:
For Advanced Time-Lapse
None of the non-Adobe programs will work with the third-party software LRTimelapse (www.lrtimelapse.com). It is an essential tool for advanced time-lapse processing. LRTimelapse works with Lightroom or ACR/Bridge to gradually shift processing settings over a sequence, and smooth annoying image flickering.
If serious and professional time-lapse shooting is your goal, none of the Adobe contenders will work. Period. Subscribe to Creative Cloud. And buy LRTimelapse.
For Basic Time-Lapse
However, for less-demanding time-lapse shooting, when the same settings can be applied to all the images in a sequence, then I feel the best non-Adobe choices are, in alphabetical order:
Corel Aftershot Pro
ON1 Photo RAW
… With, in my opinion, DxO and Capture One having the edge for image quality and features. But all five have a Library or Browser mode with easy-to-use Copy & Paste and Batch Export functions needed for time-lapse preparation.
Also worth a try is PhotoDirector9 (MacOS and Windows), a good Lightroom replacement. Scroll to the end for more details and a link.
For Still Image Nightscapes
If you are processing just individual still images, perhaps needing only to stack or composite a few exposures, and want to do all the raw development and subsequent layering of images within one non-Adobe program, then look at (again alphabetically):
ON1 Photo RAW 2018
… With Affinity Photo having the edge in offering a readily-available function off its File menu for stacking images, either for noise smoothing (Mean) or creating star trails (Maximum).
However, I found its raw development module did not produce as good a result as most competitors due to Affinity’s poorer noise reduction and less effective shadow and highlight controls. Using Affinity’s “Develop Persona” module, I could not make my test image look as good as with other programs.
Luminar 2018 has better noise reduction but it demands more manual work to stack and blend images.
While ON1 Photo Raw has some fine features and good masking tools, it exhibits odd de-Bayering artifacts, giving images a cross-hatched appearance at the pixel-peeping level. Sky backgrounds just aren’t smooth, even after noise reduction.
To go into more detail, these are the key factors I used to compare programs.
Absolutely essential is effective noise reduction, of luminance noise and chrominance color speckles and splotches.
Ideally, programs should also have a function for suppressing bright “hot” pixels and dark “dead” pixels.
Here’s what I consider to be the “gold standard” for noise reduction, Adobe Camera Raw’s result using the latest processing engine in ACR v10/Photoshop CC 2018.
I judged other programs on their ability to produce results as good as this, if not better, using their noise reduction sliders. Some programs did better than others in providing smooth, noiseless skies and ground, while retaining detail.
For example, one of the best was DxO PhotoLab, above. It has excellent options for reducing noise without being overwhelming in its choices, the case with a couple of other programs. For example, DxO has a mostly effective dead/hot pixel removal slider.
ACR does apply such a hot pixel removal “under the hood” as a default, but often still leaves many glaring hot specks that must be fixed later in Photoshop.
Comparing Noise Reduction
Above are 8 of the contender programs compared to Camera Raw for noise reduction.
Missing from this group is the brand new Pixelmator Pro, for MacOS only. It does not yet have any noise reduction in its v1 release, a serious deficiency in imaging software marketed as “Pro.” For that reason alone, I cannot recommend it. I describe its other deficiencies below.
The wide-angle lenses we typically use in nightscape and time-lapse imaging suffer from vignetting and lens distortions. Having software that can automatically detect the lens used and apply bespoke corrections is wonderful.
Only a few programs, such as Capture One (above), have a library of camera and lens data to draw upon to apply accurate corrections with one click. With others you have to dial in corrections manually by eye, which is crude and inaccurate.
Shadows and Highlights
All programs have exposure and contrast adjustments, but the key to making a Milky Way nightscape look good is being able to boost the shadows (the dark ground) while preventing the sky from becoming overly bright, yet while still applying good contrast to the sky.
Of the contenders, I liked DxO PhotoLab best (shown above), not only for its good shadow and highlight recovery, but also excellent “Smart Lighting” and “ClearView” functions which served as effective clarity and dehaze controls to snap up the otherwise low-contrast sky. With most other programs it was tough to boost the shadows without also flattening the contrast.
On the other hand, Capture One’s excellent layering and local adjustments did make it easier to brush in adjustments just to the sky or ground.
However, any local adjustments like those will be feasible only for still images or time-lapses where the camera does not move. In any motion control sequences the horizon will be shifting from frame to frame, making precise masking impractical over a sequence of hundreds of images.
Therefore, I didn’t place too much weight on the presence of good local adjustments. But they are nice to have. Capture One, DxO PhotoLab, and ON1 win here.
Selective Color Adjustments
All programs allow tweaking the white balance and overall tint.
But it’s beneficial to also adjust individual colors selectively, to enhance red nebulas, enhance or suppress green airglow, bring out green grass, or suppress yellow or orange light pollution.
Some programs have an HSL panel (Hue, Saturation, Lightness) or an equalizer-style control for boosting or dialing back specific colors.
Capture One (above) has the most control over color correction, with an impressive array of color wheels and sliders that can be set to tweak a broad or narrow range of colors.
And yet, despite this, I was still unable to make my test image look quite the way I wanted for color balance. ACR and DxO PhotoLab still won out for the best looking final result.
Copy and Paste Settings
Even when shooting nightscape stills we often take several images to stack later. It’s desirable to be able to process just one image, then copy and paste its settings to all the others in one fell swoop. And then to be able to inspect those images in thumbnails to be sure they all look good.
Some programs (Affinity Photo, Luminar, Pixelmator Pro) lack any library function for viewing or browsing a folder of thumbnail images. Yes, you can export a bunch of images with your settings applied as a user preset, but that’s not nearly as good as actually seeing those images displayed in a Browser mode.
What’s ideal is a function such as ON1 Photo RAW displays here, and that some other programs have: the ability to inspect a folder of images, work on one, then copy and paste its settings to all the others in the set.
This is absolutely essential for time-lapse work, and nice to have even when working on a small set to be stacked into a still image.
Once you develop a folder of raw images with “Copy and Paste,” you now have to export them with all those settings “baked into” the exported files.
This step is to create an intermediate set of JPGs to assemble into a movie. Or perhaps to stack into a star trail composite using third party software such as StarStaX, or to work on the images in another layer-based program of your choice.
As ON1 Photo RAW shows above, this is best done using a Library or Browser mode to visually select the images, then call up an Export panel or menu to choose the image size, format, quality, and location for the exports.
Click Export and go for coffee – or a leisurely dinner – while the program works through your folder. All programs took an hour or more to export hundreds of images.
Those functions were the key features I looked for when evaluating the programs for nightscape and time-lapse work.
Every program had other attractive features, often ones I wished were in Adobe Camera Raw. But if the program lacked any of the above features, I judged it unsuitable.
Yes, the new contenders to the Photoshop crown have the benefit of starting from a blank slate for interface design.
Many, such as Luminar 2018 above, have a clean, attractive design, with less reliance on menus than Photoshop.
Photoshop has grown haphazardly over 25 years, resulting in complex menus. Just finding key functions can take many tutorial courses!
But Adobe dares to “improve” Photoshop’s design and menu structure at its peril, as Photoshop fans would scream if any menus they know and love were to be reorganized!
The new mobile-oriented Lightroom CC is Adobe’s chance to start afresh with a new interface.
Summary Table of Key Features
Fair = Feature is present but doesn’t work as easily or produce as good a result
Partial = Program has lens correction but failed to fully apply settings automatically / DxO has a Browse function but not Cataloging
Manual = Program has only a manually-applied lens correction
– = Program is missing that feature altogether
I could end the review here, but I feel it’s important to present the evidence, in the form of screen shots of all the programs, showing both the whole image, and a close-up to show the all-important noise reduction.
ACDSee Photo Studio
PROS: This capable cataloging program has good selective color and highlight/shadow recovery, and pretty smooth noise reduction. It can copy and paste settings and batch export images, for time-lapses. It is certainly affordable, making it a low-cost Lightroom contender.
CONS: It lacks any gradient or local adjustments, or even spot removal brushes. Lens corrections are just manual. There is no dehaze control, which can be useful for snapping up even clear night skies. You cannot layer images to create composites or image stacks. This is not a Photoshop replacement.
PROS: Affinity supports image layers, masking with precise selection tools, non-destructive “live” filters (like Photoshop’s Smart Filters), and many other Photoshop-like functions. It has a command for image stacking with a choice of stack modes for averaging and adding images.
It’s a very powerful but low cost alternative to Photoshop, but not Lightroom. It works fine when restricted to working on just a handful of images.
CONS: Affinity has no lens correction database, and I found it hard to snap up contrast in the sky and ground without washing them out, or having them block up. Raw noise reduction was acceptable but not up to the best for smoothness. It produced a blocky appearance. There are no selective color adjustments.
Nor is there any library or browse function. You can batch export images, but only through an unfriendly dialog box that lists images only by file name – you cannot see them. Nor can you copy and paste settings visually, but only apply a user-defined “macro” to develop images en masse upon export.
This is not a program for time-lapse work.
Capture One 11
PROS: With version 11 Capture One became one of the most powerful raw developers, using multiple layers to allow brushing in local adjustments, a far better method than Adobe Camera Raw’s local adjustment “pins.” It can create a catalog from imported images, or images can be opened directly for quick editing. Its noise reduction was good, with hot pixel removal lacking in Camera Raw.
Its color correction options were many!
It can batch export images. And it can export files in the raw DNG format, though in tests only Adobe Camera Raw was able to read the DNG file with settings more or less intact.
CONS: It’s costly to purchase, and more expensive than Creative Cloud to subscribe to. Despite all its options I could never quite get as good looking an image using Capture One, compared to DxO PhotoLab for example.
It is just a Lightroom replacement; it can’t layer images.
Corel Aftershot Pro 3
PROS: This low-cost option has good noise reduction using Athentech’s Perfectly Clear process, with good hot pixel or “impulse” noise removal. It has good selective color and offers adjustment layers for brushing in local corrections. And its library mode can be used to copy and paste settings and batch export images.
Again, it’s solely a Lightroom alternative.
CONS: While it has a database of lenses, and identified my lens, it failed to apply any automatic corrections. Its shadow and highlight recovery never produced a satisfactory image with good contrast. Its local adjustment brush is very basic, with no edge detection.
PROS: I found DxO produced the best looking image, better perhaps than Camera Raw, because of its DxO ClearView and Smart Lighting options. It has downloadable camera and lens modules for automatic lens corrections. Its noise reduction was excellent, with its PRIME option producing by far the best results of all the programs, better perhaps than Camera Raw, plus with hot pixel suppression.
DxO has good selective color adjustments, and its copy and paste and batch export work fine.
CONS: There are no adjustment layers as such. Local adjustments and repairing are done through the unique U-Point interface which works something like ACR’s “pins,” but isn’t as visually intuitive as masks and layers. Plus, DxO is just a raw developer; there is no image layering or compositing. Nor does it create a catalog as such.
So it is not a full replacement for either Lightroom or Photoshop. But it does produce great looking raw files for export (even as raw DNGs) to other programs.
PROS: Luminar has good selective color adjustments, a dehaze control, and good contrast adjustments for highlights, mid-tones, and shadows. Adjustments can be added in layers, making them easier to edit. Noise reduction was smooth and artifact-free, but adjustments were basic. Many filters can be painted on locally with a brush, or with a radial or gradient mask.
CONS: It has no lens correction database; all adjustments are manual. The preview was slow to refresh and display results when adjusting filters. The interface is clean but always requires adding filters to the filter panel to use them when creating new layers. Its batch export is crude, with only a dialog box and no visual browser to inspect or select images.
Settings are applied as a user preset on export, not through a visual copy-and-paste function. I don’t consider that method practical for time-lapses.
ON1 Photo RAW 2018
PROS: ON1 is the only program of the bunch that can: catalog images, develop raw files, and then layer and stack images, performing all that Lightroom and Photoshop can do. It is fast to render previews in its “Fast” mode, but in its “Accurate” mode ON1 is no faster than Lightroom. It has good layering and masking functions, both in its Develop mode and in its Photoshop-like Layers mode.
Selective color and contrast adjustments were good, as was noise reduction. Developing, then exporting a time-lapse set worked very well, but still took as long as with Lightroom or Photoshop.
CONS: Despite promising automatic lens detection and correction, ON1 failed to apply any vignetting correction for my 20mm Sigma lens. Stars exhibited dark haloes, even with no sharpening, dehaze, or noise reduction applied. Its de-Bayering algorithm produced a cross-hatched pattern at the pixel level, an effect not seen on other programs.
Noise reduction did not smooth this. Thus, image quality simply wasn’t as good.
PROS: It is low cost. And it has an attractive interface.
CONS: As of version 1 released in November 2017 Pixelmator Pro lacks: any noise reduction (it’s on their list to add!), any library mode or copy and paste function, nor even the ability to open several images at once displayed together.
It is simply not a contender for “Photoshop killer” for any photo application, despite what click-bait “reviews” promise, ones that only re-write press releases and don’t actually test the product.
Raw Therapee v5.3
PROS: It’s free! It offers an immense number of controls and sliders. You can even change the debayering method. It detects and applies lens corrections (though in my case only distortion, not vignetting). It has good selective color with equalizer-style sliders. It has acceptable (sort of!) noise reduction and sharpening with a choice of methods, and with hot and dead pixel removal.
It can load and apply dark frames and flat fields, the only raw developer software that can. This is immensely useful for deep-sky photography.
CONS: It offers an immense number of controls and sliders! Too many! It is open source software by committee, with no one in charge of design or user friendliness. Yes, there is documentation, but it, too, is a lot to wade through to understand, especially with its broken English translations. This is software for digital signal processing geeks.
But worst of all, as shown above, its noise reduction left lots of noisy patches in shadows, no matter what combination of settings I applied. Despite all its hundreds of sliders, results just didn’t look as good.
What About …? (updated December 28)
No matter how many programs I found to test, someone always asks, “What about …?” In some cases such comments pointed me to programs I wasn’t even aware of, but subsequently tried out. So here are even more to pick from…
Billed as having “everything you need in an image editor,” this low-cost ($30) MacOS-only program is anything but. Its raw developer module is crude and lacks any of the sophisticated range of adjustments offered by all the other programs on offer here. It might be useful as a layer-based editor of images developed by another program.
Available for Mac and Windows for $150, this Lightroom competitor offers a good browser function, with the ability to “copy-from-one and paste-to-many” images (unlike some of the programs below), and a good batch export function for time-lapse work. It has good selective color controls and very good noise reduction providing a smooth background without artifacts like blockiness or haloes. Local adjustments, either through brushed-on adjustments or through gradients, are applied via handy and easy to understand (I think!) layers.
While it has auto lens corrections, its database seemed limited — it did not have my Sigma 20mm lens despite it being on the market for 18 months. Manual vignetting correction produced a poor result with just a washed out look.
The main issue was that its shadow, highlight, and clarity adjustments just did not produce the snap and contrast I was looking for, but that other programs could add to raw files. Still, it looks promising, and is worth a try with the trial copy. You might find you like it. I did not. For similar cost, other programs did a better job, notably DxO PhotoLab.
In the same ilk as Raw Therapee, I also tested out another free, open-source raw developer, one simply called “darktable,” with v2.2.5 shown below. While it has some nice functions and produced a decent result, it took a lot of time and work to use.
The MacOS version I tried (on a brand new 5K iMac) ran so sluggishly, taking so long to re-render screen previews, that I judged it impractical to use. Sliders were slow to move and when I made any adjustments often many seconds would pass before I would see the result. Pretty frustrating, even for free.
A similar crowd-developed raw processing program, Iridient Developer (above), sells for $99 US. I tested a trial copy of v3.2. While it worked OK, I was never able to produce a great looking image with it. It had no redeeming features over the competition that made its price worthwhile.
Using Parallels running Windows 10 on my Mac, I did try out this popular Windows-only program from Corel. By itself, Paintshop Pro’s raw developer module (shown above) is basic, crude and hardly up to the tax of processing demanding raw files. You are prompted to purchase Corel’s Aftershot Pro for more capable raw development, and I would agree – Aftershot would be an essential addition. However …
As I showed above, I did test the MacOS version of Aftershot Pro on my raw sample image, and found it did the poorest job of making my raw test image look good. Keep in mind that it is the ability of all these programs to develop this typical raw nightscape image that I am primarily testing.
That said, given a well-developed raw file, Paintshop Pro can do much more with it, such as further layering of images and applying non-destructive and masked adjustment layers, as per Photoshop. Indeed, it is sold as a low-cost (~ $60) Photoshop replacement. As such, many Windows users find Paintshop’s features very attractive. However, Paintshop lacks the non-destructive “smart” filters, and the more advanced selection and masking options offered by Photoshop, Affinity Photo, and ON1 Photo Raw. If you have never used these, you likely don’t realize what you are missing.
If it’s an Adobe alternative you are after, I would suggest Windows users would be better served by other options. Why not test drive Affinity and ON1?
This was a surprising find. Little known, certainly to me, this Windows and MacOS program from the Taiwanese company Cyberlink, is best described as a Lightroom substitute, but it’s a good one. Its regular list price is $170. I bought it on sale for $60.
Like Lightroom, working on any images with PhotoDirector requires importing them into a catalog. You cannot just browse to the images. Fine. But one thing some people complain about with Lightroom is the need to always import images.
I was impressed with how good a job PhotoDirector did on my raw test image. PhotoDirector has excellent controls for shadow and highlight recovery, HSL selective color, copying-and-pasting settings, and batch exporting. So it will work well for basic time-lapse processing.
Noise reduction was very good and artifact-free. While it does have automatic lens corrections, its database did not include the 2-year old Sigma 20mm Art lens I used. So it appears its lens data is not updated frequently.
PhotoDirector has good local adjustments and gradients using “pins” rather than layers, similar to Camera Raw and Lightroom.
After performing raw image “Adjustments,” you can take an image into an Edit module (for adding special effects), then into a Layers module for further work. However, doing so destructively “flattens” the image to apply the raw adjustments you made. You cannot go back and tweak the raw settings in the Adjustment module, as you can when opening a raw file as a “smart object” in Adobe Photoshop.
While PhotoDirector does allow you to layer in other images to make basic composites (such as adding type or logos), there is no masking function nor any non-destructive adjustment layers. So this is most assuredly not a Photoshop substitute, despite what the advertising might suggest. But if it’s a Lightroom replacement you are after, do check it out in a trial copy.
This little-known MacOS-only program (only $40 on sale) for developing raw images looks very attractive, with good selective color, lots of local adjustments, and good masking tools, the features promoted on the website. It does have a browse function and can batch export a set of developed files.
However … its noise reduction was poor, introducing glowing haloes around stars when turned up to any useful level. Its shadows, highlights, and contrast adjustments were also poor – it was tough to make the test image look good without flattening contrast or blocking up shadows. Boosting clarity even a little added awful dark haloes to stars, making this a useless function. It has no lens correction, either automatic or manual. Like Topaz Studio, below, it cannot copy and paste settings to a batch of images, only to one image at a time, so it isn’t useful for time-lapse processing.
I cannot recommend this program, no matter how affordable it might be.
Popular among some camera manufacturers as their included raw developer, Silky Pix can be purchased separately ($80 list price for the standard version, $250 list price for the Pro version) with support for many cameras’ image files. It is available for MacOS and Windows. I tried the lower-cost “non-Pro” version 8. It did produce a good-looking end result, with good shadow and highlight recovery, and excellent color controls. Also on the plus side, Silky Pix has very good copy-and-paste functions for development settings, and good batch export functions, so it can be used to work on a folder of time-lapse frames.
On the down side, noise reduction, while acceptable, left an odd mottled pattern, hardly “silky.” The added “Neat” noise reduction option only smoothed out detail and was of little value except perhaps for very noisy images. Noise reduction did nothing to remove hot pixels, leaving lots of colored specks across the image. The program uses unorthodox controls whose purposes are not obvious. Instead of Highlights and Shadows you get Exposure Bias and HDR. Instead of Luminance and Color noise reduction, you get sliders labeled Smoothness and Color Distortion. You really need to read the extensive documentation to learn how to use this program.
I found sliders could be sticky and not easy to adjust precisely. The MacOS version was slow, often presenting long bouts of spinning beachballs while it performed some function. This is a program worth a try, and you might find you like it. But considering what the competition offers, I would not recommend it.
While Topaz Labs previously offered only plug-ins for Photoshop and other programs (their Topaz DeNoise 6 is very good), their Topaz Studio stand-alone program now offers full raw processing abilities.
It is for Mac and Windows. While it did a decent job developing my test Milky Way image (above), with good color and contrast adjustments, it cannot copy and paste settings from one image to a folder of images, only to one other image. Nor can it batch export a folder of images. Both deficiencies make it useless for time-lapse work.
In addition, while the base program is free, adding the “Pro Adjustments” modules I needed to process my test image (Noise Reduction, Dehaze, Precision Contrast, etc.) would cost $160 – each Adjustment is bought separately. Some users might like it, but I wouldn’t recommend it.
And … Adobe Photoshop Elements v18 (late 2017 release)
What about Adobe’s own Photoshop “Lite?” Elements is available for $99 as a boxed or downloadable one-time purchase, but with annual updates costing about $50. While it offers image and adjustment layers, it cannot do much with 16-bit images, and has very limited functions for developing raw files.
And its Lightroom-like Organizer module does not have any copy-and-paste settings or batch export functions, making it unsuitable for time-lapse production.
Elements is for processing photos for the snapshot family album. Like Apple’s Photos and other free photo apps, I don’t consider Elements to be a serious option for nightscape and time-lapse work. But it can be pressed into service for raw editing and layering single images, especially by beginners.
However, a Creative Cloud Photo subscription doesn’t cost much more than buying, then upgrading Elements outright, yet gets you far, far more in professional-level software.
And Yet More…!
In addition, for just developing raw files, you likely already have software to do the job – the program that came with your camera.
For Canon it’s Digital Photo Professional (shown above); for Nikon it’s Capture NX; for Pentax it’s Digital Camera Utility, etc.
These are all capable raw developers, but have no layering capabilities. And they read only the files from their camera brand. If theirs is the only software you have, try it. They are great for learning on.
But you’ll find that the programs from other companies offer more features and better image quality.
What Would I Buy?
Except for Capture One, which I tested as a trial copy, I did buy all the software in question, for testing for my Nightscapes eBook.
However, as I’ve described, none of the programs tick all the boxes. Each has strengths, but also weaknesses, if not outright deficiencies. I don’t feel any can fully replace Adobe products for features and image quality.
A possible non-Adobe combination for the best image quality might be DxO PhotoLab for raw developing and basic time-lapse processing, and Affinity Photo for stacking and compositing still images, from finished TIFF files exported out of DxO and opened and layered with Affinity.
But that combo lacks any cataloging option. For that you’d have to add ACDSee or Aftershot for a budget option. It’s hardly a convenient workflow I’d want to use.
I’d love to recommend ON1 Photo RAW more highly as a single solution, if only it had better raw processing results, and didn’t suffer from de-Bayering artifacts (shown in a 400% close-up above, compared to DxO PhotoLab). These add the star haloes and a subtle blocky pattern to the sky, most obvious at right.
To Adobe or Not to Adobe
I’m just not anxious, as others are, to “avoid Adobe.”
I’ve been a satisfied Creative Cloud subscriber for several years, and view the monthly fee as the cost of doing business. It’s much cheaper than the annual updates that boxed Photoshop versions used to cost. Nor am I worried about Adobe suddenly jacking up the fees or holding us hostage with demands.
For me, the need to use LRTimelapse (shown above) for about 80 percent of all the time-lapse sequences I shoot means the question is settled. LRTimelapse works only with Adobe software, and the combination works great. Sold.
I feel Camera Raw/Lightroom produces results that others can only just match, if that.
Only DxO PhotoLab beat Adobe for its excellent contrast enhancements and PRIME noise reduction.
Yes, other programs certainly have some fine features I wish Camera Raw or Lightroom had, such as:
Hot and dead pixel removal
Dark frame subtraction and flat field division
Better options for contrast enhancement
And adding local adjustments to raw files via layers, with more precise masking tools
But those aren’t “must haves.”
Using ACR or Lightroom makes it easy to export raw files for time-lapse assembly, or to open them into Photoshop for layering and compositing, usually as “smart objects” for non-destructive editing, as shown below.
Above is the final layered image, consisting of:
A stack of 4 tracked exposures for the sky (the test image is one of those exposures)
And 4 untracked exposures for the ground.
The mean stacking smooths noise even more. The masking reveals just the sky on the tracked set. Every adjustment layer, mask, and “smart filter” is non-destructive and can be adjusted later.
I’ll work on recreating this same image with the three non-Adobe programs capable of doing so – Affinity, Luminar, and ON1 Photo RAW – to see how well they do. But that’s the topic of a future blog.
Making the Switch?
The issue with switching from Adobe to any new program is compatibility.
While making a switch will be fine when working on all new images, reading the terabytes of old images I have processed with Adobe software (and being able to re-adjust their raw settings and layered adjustments) will always require that Adobe software.
If you let your Creative Cloud subscription lapse, as I understand it the only thing that will continue to work is Lightroom’s Library module, allowing you to review images only. You can’t do anything to them.
None of the contender programs will read Adobe’s XMP metadata files to display raw images with Adobe’s settings intact.
Conversely, nor can Adobe read the proprietary files and metadata other programs create.
With final layered Photoshop files, while some programs can read .PSD files, they usually open them just as flattened images, as ON1 warns it will do above. It flattened all of the non-destructive editing elements created in Photoshop. Luminar did the same.
Only Affinity Photo (above) successfully read a complex and very large Photoshop .PSB file correctly, honouring at least its adjustment and image layers. So, if backwards compatibility with your legacy Photoshop images is important, choose Affinity Photo.
However, Affinity flattened Photoshop’s smart object image layers and their smart filters. Even Adobe’s own Photoshop Elements doesn’t honor smart objects.
Lest you think that’s a “walled garden” created by “evil Adobe,” keep in mind that the same will be true of the image formats and catalogs that all the contender programs produce.
To read the adjustments, layers, and “live filters” you create using any another program, you will need to use that program.
Will Affinity, DxO, Luminar, ON1, etc. be around in ten years?
Yes, you can save out flattened TIFFs that any program can read in the future, but that rules out using those other programs to re-work any of the image’s original settings.
I can see using DxO PhotoLab (above) or Raw Therapee for some specific images that benefit from their unique features.
Or using ACDSee as a handy image browser.
And ON1 and Luminar have some lovely effects that can be applied by calling them up as plug-ins from within Photoshop, and applied as smart filters. Above, I show Luminar working as a plug-in, applying its “Soft & Airy” filter.
In the case of Capture One and DxO PhotoLab, their ability to save images back as raw DNG files (the only contender programs of the bunch that can), means that any raw processing program in the future should be able to read the raw image.
However, only Capture One’s Export to DNG option produced a raw file readable and editable by Adobe Camera Raw with its settings from Capture One (mostly) intact (as shown above).
Even so, I won’t be switching away from Adobe any time soon.
But I hope my survey has given you useful information to judge whether you should make the switch. And if so, to what program.
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!
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.
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.
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.
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
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
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
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.
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
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
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
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.
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
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
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
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.
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.
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
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
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
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
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.
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 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.
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.
Following up on my earlier tests, I compare the new Canon 6D MkII camera to earlier Canon full-frame models in long, tracked exposures of the Milky Way.
A month ago I published tests of the new Canon 6D MkII camera for nightscape images, ones taken using a fixed tripod in which exposures usually have to be limited to no longer than 30 to 60 seconds, to prevent star trailing.
Despite these short exposures, we still like to extract details from the dark shadows of the scene, making nightscape images a severe test of any camera.
Here I test the 6D MkII for what, in many respects, is a less demanding task: shooting long exposures of deep-sky objects, the Milky Way in Cygnus in this case.
Why is this an easier task? The camera is now on a tracking mount (I used the new Sky-Watcher Star Adventurer Mini) which is polar aligned to follow the rotation of the sky. As such, exposures can now be many minutes long if needed. We can give the camera sensor as much signal as the darkness of the night sky allows. More signal equals less noise in the final images.
In addition, there are no contrasty, dark shadows where noise lurks. Indeed, the subjects of deep-sky images are often so low in contrast, as here, they require aggressive contrast boosting later in processing to make a dramatic image.
While that post-processing can bring out artifacts and camera flaws, as a rule I never see the great increase in noise, banding, and magenta casts I sometimes encounter when processing short-exposure nightscape scenes.
For this test, I shot the same region of sky with the same 35mm lens L-Series lens at f/2.2, using three cameras:
• Canon 6D MkII (2017)
• Canon 6D (2012)
• Canon 5D MkII (2008)
Note that the 5D MkII has been “filter-modified” to make its sensor more sensitive to the deep red wavelengths emitted by hydrogen gas, the main component of the nebulas along the Milky Way. You’ll see how it picks up the red North America Nebula much better than do the two off-the-shelf “stock” cameras. (Canon had their own factory-modified “a” models in years past: the 20Da and 60Da. Canon: How about a 6D MkIIa?)
I shot at four ISO speeds typical of deep-sky images: 800, 1600, 3200, and 6400.
Exposures were 4 minutes, 2 minutes, 1 minute, and 30 seconds, respectively, to produce equally exposed frames with a histogram shifted well to the right, as it should be for a good signal-to-noise ratio.
Noisy deep-sky images with DSLR cameras are usually the result of the photographer underexposing needlessly, often in the mistaken belief that doing so will reduce noise when, in fact, it does just the opposite.
The above set of three images compares each of the three cameras at those four ISO speeds. In all cases I have applied very little processing to the images: only a lens correction, some sharpening, a slight contrast and clarity increase, and a slight color correction to neutralize the background sky.
However, I did not apply any luminance noise reduction. So all the images are noisier than what they would be in a final processed image.
Even so, all look very good. And with similar performance.
All frames were shot with Long Exposure Noise Reduction (LENR) on, for an automatic dark frame subtraction by the camera. I saw no artifacts from applying LENR vs. shots taken without it.
The 6D and 6D MkII perhaps show a little less noise than the old 5D MkII, as they should being newer cameras.
The 6D MkII also shows a little less pixelation on small stars, as it should being a 26 megapixel camera vs. 20 to 21 megapixels for the older cameras. However, you have to examine the images at pixel-peeping levels to see these differences. Nevertheless, having higher resolution without the penalty of higher noise is very welcome.
Above, I show images from the three cameras side by side at ISOs 1600, 3200, and 6400. It is tough to tell the difference in noise levels, the key characteristic for this type of astrophotography.
The new 6D MkII shows very similar levels of noise to the 6D, perhaps improving upon the older cameras a tad.
Because images are well-exposed (note the histogram at right), the 6D MkII is showing none of the flaws of its lower dynamic range reported elsewhere.
That’s the key. The 6D MkII needs a well-exposed image. Given that, it performs very well.
This version shows the same images but now with stacked frames and with a typical level of processing to make a more attractive and richer final image. Again, all look good, but with the modified camera showing richer nebulosity, as they do in deep-sky images.
The lead image at the very top is a final full-frame image with the Canon 6D MkII.
As such, based on my initial testing, I can recommend the Canon 6D MkII (and plan to use it myself) for deep-sky photography.
Indeed, I’ll likely have the camera filter-modified to replace my vintage yet faithful 5D MkII for most of my deep-sky shooting. The 6D MkII’s tilting LCD screen alone (a neck, back, and knee saver when attached to a telescope!) makes it a welcome upgrade from the earlier cameras.
The only drawback to the 6D MkII for deep-sky work is its limited dark frame buffer. As noted in my earlier review, it can shoot only three Raw files in rapid succession with Long Exposure Noise Reduction turned on. The 5D MkII can shoot five; the 6D can shoot four. (A 6D MkIIa should have this buffer increased to at least 4, if not 8 images.)
I make use of this undocumented feature all the time to ensure cleaner images in long deep-sky exposures, as it produces and subtracts dark frames with far greater accuracy than any taken later and applied in post-processing.
I hope you’ve found this report of interest.
With the 6D MkII so new, and between smoky skies and the interference of the Moon, I’ve had only one night under dark skies to perform these tests. But the results are promising.
For more tips on deep-sky imaging and processing see my pages on my website:
In a technical blog I compare the new Canon 6D Mark II camera with its predecessor, the Canon 6D, with the focus on performance for nightscape astrophotography.
No pretty pictures in this blog I’m afraid! This is a blog for gear geeks.
The long-awaited Canon 6D Mark II camera is out, replacing the original 6D after that camera’s popular 5-year reign as a prime choice among astrophotographers for all kinds of sky images, including nightscapes and time-lapses.
As all new cameras do, the 6D Mark II is currently fetching a full list price of $2000 U.S. Eventually it will sell for less. The original 6D, introduced in 2012 at that same list price, might still be available from many outlets, but for less, likely below $1500 US.
Shown on the left, above, the 6D Mark II is similar in size and weight to the original 6D.
However, the new Mark II offers 6240 x 4160 pixels for 26 megapixels, a bump up in resolution over the 5472 x 3648 20-megapixel 6D. The pixel pitch of the Mark II sensor is 5.7 microns vs. 6.6 microns for the 6D.
One difference is that the port for a remote release is now on the front, but using the same solid 3-pin N3 connector as the 6D and other full-frame Canons. That makes it compatible with all external controllers for time-lapse shooting.
TESTING FOR THE NIGHT
My interest is in a camera’s performance for long-exposure astrophotography, with images taken at high ISO settings. I have no interest in auto-focus performance (we shoot at night with focus set manually), nor how well a camera works for high-speed sports shooting.
To test the Mark II against the original 6D I took test shots at the same time of a high-contrast moonlit scene in the backyard, using a range of ISO speeds typical of nightscape scenes.
The comparisons show close-ups of a scene shown in full in the smaller inset screen.
The key characteristic of interest for night work is noise. How well does the camera suppress the noise inherent in digital images when the signal is boosted to the high ISO settings we typically use?
This set shows the 6D MkII at five ISOs, from ISO 1600 all the way up to the seldom-used ISO 25,600, all shot in Raw, not JPG. In all cases, no noise reduction was applied in later processing, so the results do look worse than what processed images would.
Click or tap on all images to expand each image to full screen for closer inspection.
This set shows the same range of ISOs with the original 6D. All were taken at the same aperture, f/2.8, with a 35mm lens. Exposures were halved for each successive bump up in ISO speed, to ensure equally exposed images.
Comparing the sets, the 6D MkII shows a much greater tendency to exhibit a magenta cast in the shadows at very high ISOs, plus a lower contrast in the shadows at increasing ISOs, and slightly more luminance noise than the 6D.
How much more noise the 6D MkII exhibits is demonstrated here.
To me, visually, the MkII presents about 1/2 stop, or EV, worse noise than the 6D.
In this example, the MkII exhibits a noise level at ISO 3200 (a common nightscape setting) similar to what the 6D does if set between ISO 4000 and 5000 – about 1/2 stop worse noise.
Frankly, this is surprising.
Yes, the MkII has a higher pixel count and therefore smaller pixels (5.7 microns in this case) that are always more prone to noise. But in the past, advances to the in-camera signal processing has prevented noise from becoming worse, despite increasing pixel count, or has even produced an improvement in noise.
For example, the 2012-vintage 6D is better for noise than Canon’s earlier 2008-era 5D MkII model by about half a stop, or EV.
After five years of camera development I would have expected a similar improvement in the 6D MkII. After all, the 6D MkII has Canon’s latest DIGIC 7 processor, vs. the older 6D’s DIGIC 5+.
Instead, not only is there no noise improvement, the performance is worse.
That said, noise performance in the 6D MkII is still very good, and better than you’ll get with today’s 24 megapixel cropped-frame cameras with their even smaller 4 micron pixels. But the full frame 6D MkII doesn’t offer quite as much an improvement over cropped-frame cameras as does the five-year-old 6D.
In the previous sets all the images were well-exposed, as best they could be for such a contrasty scene captured with a single exposure.
What happens when Raw images are underexposed, then boosted later in exposure value in processing?
This is not an academic question, as that’s often the reality for nightscape images where the foreground remains dark. Bringing out detail in the shadows later requires a lot of Shadow Recovery or increasing the Exposure. How well will the image withstand that work on the shadows?
To test this, I shot a set of images at the same shutter speed, but at successively slower ISOs, from a well-exposed ISO 3200, to a severely underexposed ISO 100. I then boosted the Exposure setting later in Raw processing by an amount that compensated for the level of underexposure in the camera, from a setting of 0 EV at ISO 3200, to a +5 EV boost for the dark ISO 100 shots.
This tests for a camera’s “ISO Invariancy.” If a camera has a sensor and signal processing design that is ISO invariant, a boosted underexposed image at a slow ISO should look similar to a normally exposed image at a high ISO.
You’re just doing later in processing what a camera does on its own in-camera when bumping up the ISO.
But cameras that use ISO “variant” designs suffer from increased noise and artifacts when severely underexposed images are boosted later in Raw processing.
The Canon 6D and 6D MkII are such cameras.
This set above shows the results from the 6D Mark II. Boosting underexposed shadows reveals a lot of noise and a severe magenta cast.
These are all processed with Adobe Camera Raw, identical to the development engine in Adobe Lightroom.
This set above shows the results from the 6D. The older camera, which was never great for its lack of ISO Invariancy performance, is still much better than the new Mark II.
Effectively, this is the lack of dynamic range that others are reporting when testing the 6D MkII on more normal daytime images. It really rears its ugly head in nightscapes.
The lesson here is that the Mark II needs to be properly exposed as much as possible.
Don’t depend on being able to extract details later from the shadows. The adage “Expose to the Right,” which I explain at length in my Nightscapes eBook, applies in spades to the 6D MkII.
DARK FRAME BUFFER
All the above images were taken with Long Exposure Noise Reduction (LENR) off. This is the function that, when turned on, forces the camera to take and internally subtract a dark frame – an image of just the noise – reducing thermal noise and discolouration in the shadows.
A unique feature of Canon full-frame cameras is that when LENR is on you can take several exposures in quick succession before the dark frame kicks in and locks up the camera. This is extremely useful for deep-sky shooting.
The single dark frame then gets applied to the buffered “light frames.”
The 6D Mark II, when in either Raw or in Raw+JPG can take 3 shots in succession. This is a downgrade from the 6D which can take 4 shots when in Raw+JPG. Pity.
ADOBE CAMERA RAW vs. DIGITAL PHOTO PROFESSIONAL
My next thought was that Adobe Camera Raw, while it was reading the Mark II files fine, might not have been de-Bayering or developing them properly. So I developed the same image with both Raw developers, Adobe’s and Canon’s latest version of their own Digital Photo Professional (DPP).
Here I did apply a modest and approximately similar level of noise reduction to both images:
In ACR: Color at 25, Luminosity at 40, with Sharpness at 25
In DPP: Chrominance at 8, Luminosity at 8, with Sharpness at 2
Yes, DPP did do a better job at eliminating the ugly magenta cast, but did a much worse job at reducing overall noise. DPP shows a lot of blockiness, detail loss, and artifacts left by the noise reduction.
Adobe Camera Raw and/or Lightroom remain among the best of many Raw developers.
A new feature the 6D Mark II offers is the ability to shoot and stack images in-camera. It can either “Add” the exposure values, or, most usefully, “Average” them, as shown here.
Other newer Canon DSLRs also offer this feature, notably the 7D MkII, the 5D MkIV, the 5Ds, and even the entry-level 80D. So the 6D MkII is not unique. But the feature was not on the 6D.
Here’s the benefit.
The left image is a single exposure; the middle is an average stack of 4 exposures stacked in camera; the right image an average stack of 9 exposures, the maximum allowed.
Noise smooths out a lot, with less noise the more images you stack. The result is a single Raw file, not a JPG. Excellent!
While this kind of stacking can be done later in processing in Photoshop, or in any layer-based program, many people might find this in-camera function handy.
Except, as you can see, the sky will exhibit star trails, and not as well defined as you would get from stacking them with a “Lighten” blend mode, as all star trail stacking routines use.
So this averaging method is NOT the way to do star trails. The Mark II does not offer the Brighten mode some other new Canons have that does allow for in-camera star trail stacking. Again, a pity in a camera many will choose for astrophotography.
Nevertheless, the Average mode is a handy way to create foreground landscapes with less noise, which then have to be composited later with a sky image or images.
On the left, below, the Mark II has a nearly identical layout of buttons and controls to the 6D on the right. So owners of the older model will feel right at home with the Mark II. That’s handy, as we astrophotographers work in the dark by feel!
Of course the big new feature, a first for Canon in a full-frame camera, is the Mark II’s fully articulated screen. It flips out, tilts, and even flips around to face forward. This is super-great for all astrophotography, especially when conducted by aging photographers with aching backs!
And the screen, as with the entry-level cropped-frame Canons, is a touch screen. For someone who hasn’t used one before – me! – that’ll take some getting used to, if only in just remembering to use it.
And it remains to be seen how well it will work in the cold. But it’s great to have.
Like other late-model Canon DSLRs, the 6D MkII has a built-in intervalometer. It works fine but is useable only on exposures with internally set shutter speeds up to 30 seconds.
However, setting the Interval so it fires the shutter with a minimal gap of 1 second between shots (our usual requirement for night time-lapses) is tricky: You have to set the interval to a value not 1 second, but 2 to 3 seconds longer than the shutter speed. i.e. an exposure of 30 seconds requires an interval of 33 seconds, as shown above. Anything less and the camera misses exposures.
Why? Well, when set to 30 seconds the camera actually takes a 32-second exposure. Surprise!
Other cameras I’ve used and tested with internal intervalometers (Nikon and Pentax) behave the same way. It’s confusing, but once you are used to it, the intervalometer works fine.
Except … the manual suggests the only way to turn it off and stop a sequence is to turn off the camera. That’s crude. A reader pointed out that it is also possible to stop a time-lapse sequence by hitting the Live View Start/Stop button. However, that trick doesn’t work on sequences programmed with only a second between frames, as described above. So stopping a night time-lapse is inelegant to say the least. With Nikons you can hold down the OK button to stop a sequence, with the option then of restarting it if desired.
Also, the internal Intervalometer cannot be used for exposures longer than 30 seconds. Again, that’s the case with all in-camera intervalometers in other models and brands.
As with many other new Canons, the Mark II has a Bulb Timer function.
When on Bulb you can program in exposure times of any length. That’s a nice feature that, again, might mean an external intervalometer is not needed for many situations.
A new feature I like is the greatly expanded information when reviewing an image.
One of the several screens you can scroll to shows whether you have shot that image with Long Exposure Noise Reduction on or not.
Excellent! I have long wanted to see that information recorded in the metadata. Digital Photo Professional also displays that status, but not Adobe Camera Raw/Lightroom.
While this has been a long report, this is an important camera for us astrophotographers.
I wish the news were better, but the 6D Mark II is somewhat of a disappointment for its image quality. It isn’t bad. It’s just that it isn’t any better than than the older 6D, and in some aspects is worse.
Canon has clearly made certain compromise decisions in their sensor design. Perhaps adding in the Dual-Pixel Autofocus for rapid focusing in Movie Mode has compromised the signal-to-noise ratio. That’s something only Canon can explain.
But the bottom-line recommendations I can offer are:
If you are a Canon user looking to upgrade to your first full-frame camera, the 6D Mark II will provide a noticeable and welcome improvement in noise and performance over a cropped-frame model. But an old 6D, bought new while they last in stock, or bought used, will be much cheaper and offer slightly less noise. But the Mark II’s flip-out screen is very nice!
If you are a current 6D owner, upgrading to a Mark II will not get you better image quality, apart from the slightly better resolution. Noise is actually worse. But it does get you the flip-out screen. I do like that!
If you are not wedded to Canon, but want a full-frame camera for the benefits of its lower noise, I would recommend the Nikon D750. I have one and love it. I have coupled it with the Sigma Art series lenses. I have not used any of the Sony a7-series Mirrorless cameras, so cannot comment on their performance, but they are popular to be sure.
The summer Milky Way sets into the southwest on a late November night.
On Saturday, November 28, well into winter here in Alberta, the stars of the Summer Triangle and the summer Milky Way set into the southwest on a clear, though slightly hazy, late November night.
This is the last of the summer Milky Way, with the centre of the Galaxy now long gone, but the Summer Triangle stars remaining in the evening sky well into autumn. Glows from light pollution in the west light the horizon, in a quick series of images shot in my rural backyard.
In the Summer Triangle, Vega is at right, as the brightest star; Deneb is above centre, and Altair is below centre, farthest south in the Milky Way.
I shot this as a test image for the Nikkor 14-24mm lens, here wide-open at f/2.8 and at 14mm, where it performs beautifully, with very tight star images to the corners. It does very well at 24mm, too! This is astonishing performance for a zoom lens. It matches or beats many “prime” lenses for quality.
The camera was the 36-megapixel Nikon D810a, Nikon’s “astronomical DSLR” camera, also on test. Here it shows its stuff by picking up the red nebulas in Cygnus and Cepheus.
Thorough tests of both the camera and lens will appear later in the year. Stay tuned.
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For the even more technically-minded, this image is a stack, mean combined, of five 2-minute tracked exposures, at f/2.8 and ISO 800. The camera was on the iOptron Sky-Tracker. So the stars are not trailed but the ground is! I made no attempt here to layer in an untracked ground shot, as there isn’t much detail of interest worth showing, quite frankly.
At least not in the ground. But the Milky Way is always photogenic.
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.
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?
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.
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.
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.
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.
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?
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?
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.
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.
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.
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
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.