First Look at Leica SL2 Multi-Shot High-Res Mode (Updated.v2 with comments)
Related: Adobe, Adobe Camera Raw, aliasing, digital artifacts, exposure, histogram, Leica, Leica M, Leica SL2, moiré, Multi-Shot High Resolution Mode, noise
re: Workflow for Multi-Shot High-Res Mode Images in Adobe Camera Raw
This page looks at multi-shot high-res mode (“HiRes” mode) of the Leica SL2.
Leica SL2 Multi-Shot High-Res Mode
Includes example image sizes up to 187 megapixels.
Triple jackass gold medal to Leica for the usability-destroying “Vibration Detected” warning.
LEICA SL2 + Leica 35mm f/2 APO-Summicron-SL ASPH
RAW: +20 Whites, +10 Clarity, USM {6,50,0}, SmartSharpen{30,0.7,20,0}
[low-res image for bot]
Andrej K writes:
As a Leica SL2 user from the end of 2020 (being a current Nikon D850/Z 7II shooter and with Nikon for the last 20 years) I tried MS for a few times and just used it on a payed project a few weeks ago.
I'll keep it short - Adobe's new "Enhance" feature in Lightroom consistently gave me better results than MS! I also went with the enhanced version being the image that was given to my client. I made the shot with my SL2 at ISO 100 with the Sigma 65/2 (not perfect, but a nice lens indeed!) at f/8 and when comparing MS vs Enhanced images, the latter was way better; more detail, less moire, less color artifacts ... simply better in most if not all aspects. It was basically a landscape shot; a large grass field with forest-covered hills in the background with blue sky covered with white clouds - nothing special with some kind of weird textures ... a pretty basic shot, really.
Both features are giving results with the same 187 Mpix, so can be easily and fairly compared. Please, do try the comparison on your own, I'm sure you'll end up with similar results. Also beware the strong and destructive posterizing when using MS at ISO 50 - in most if not all cases impossible to be used on images including any significant part of the sky.
If you're interested, I can send you the files I'm talking about, but I'm sure you'll get the same results ... unless my copy of SL2 is somehow defective...
DIGLLOYD: valid concerns of course. And it is on my to-do list to look at Enhance Details for single-shot Leica SL2 files (I included one in the series above). Certainly if a shot looks better, then it is better. But let me point out some doubts about what is stated above.
Enhance Details has had pattern noise problems in the past, namely crosshatching pattern noise. I have documented unpleasant artifacts from Enhance Details with 3 or 4 different cameras over some years. However, I have not seen if it's an issue with the Leica SL2, and I have not rechecked to see if anything has been fixed in recent updates—Adobe had promised an improvement to me (privately) well over a year ago but said there might be a long delay. There is also Adobe Camera Raw SuperRes mode, which incorporates Enhance Details and does smart upscaling.
UPDATE: ACR SuperRes mode looks great on the pumpkin shot and in some ways better (as Andrej K stated), such as on the fine prickly hairs on the pumpkin vine. However, a single-shot frame with SuperRes has notably more noise in some areas than with HiRes mode. OTOH, the noise actually looks good in some areas, spurious detail though it is. It makes me wonder if ACR SuperRes mode could be hand-tailored to HiRes captures, but only Enhance Details work, and I did not see any improvement on HiRes files.
UPDATE2: closer inspect reveals that both Multi-Shot High-Res mode and Adobe Camera Raw Super Resolution Mode have significant image quality flaws, which I detail/show. And when I went looking, I found some serious artifacting flaws in ACR SuperRes mode in other images—ugly stuff that would preclude its use because it looks very unnatural.
It’s clear that HiRes mode has strictly limited benefits in a depth of field zone half as deep as single-shot, and I'd agree that it has no advantage outside that narrow zone at f/8, a little more at f/5.6. So you have to find benefits that exceed single-shot mode + Enhanced Details.
HiRes mode seems to dull the image such as on surfaces catching the light. I don’t know if this is a diffraction dulling effect or a side-effect of the merging of the 8 frames—maybe both.
I have never seen moiré or color aliasing in HiRes mode on the Panasonic S1R at least, and that should be true on the Leica SL2 also. So the “less moiré, less color artifacts” comment seems nonsensical to me. I'd bet that the comment has something to do with motion artifacts, not moiré or color aliasing. And those definitely exist with the SL2 HiRes mode, though I hadn’t shown it yet. A HiRes DNG that shows moiré or color aliasing would be a surprise to me, but bring it on. BTW, Enhance Details is not always successful in removing all moiré.
UPDATE: I processed Andrej’s DNG files. There is no moiré or color aliasing. But there are ugly effects which are the result of subject motion. See my detailed analysis of MultiShot motion artifact problems with the Leica SL2.
Enhance Details absolutely cannot deliver the ultra-low noise of HiRes mode. Those 8 shots means sqrt(8) less noise ~2.8X less, equivalent to ISO 35 (vs ISO 100). OTOH, a little noise gives the perceptual effect of looking sharper.
Multi-shot and ISO 50
The Leica SL2 has incompetent metering in general (way too many blown-out items compared to my Sony A1). And at ISO 50 it meters a full stop slower when in fact ISO 50 is not a real ISO and has only 2/3 stop more latitude. If using ISO 50, always dial in -1/3 stop for auto metering. The SL2 makes matters far worse by at not having an RGB histogram, which would make it obvious that a color channel is blown out. That is critically important for my work in the outdoors; I check exposure with the RGB histogram just about ever shot to make sure I nailed it. IMO the SL2 fails as a professional camera if only because of the lack of the RGB histogram——it’s that important—unbelievably stupid design for real-world photography.
TESTED: with proper exposure, there is no issue in using ISO 50 with MultiShot on the Leica SL2.
Posterization at ISO 50 is due to exposure error, the proof of that shown below. Leica SL2 metering blows out the sky in MultiShot mode (probably due to the way the 8 frames are assembled), thus posterizing the result.
As shown below, the posterization is eliminated by dialing in -1/3 stop exposure compensation (shutter speed of 1/160 second instead of 1/125). A camera RGB histogram would show instantly that this area was blown-out, but the Leica SL2 doesn’t have one, making it an absurdity for professional use, IMO.
With the lack of an RGB histogram and the metering error, it is probably best to not use ISO 50 on the Leica SL2; it’s too hard to know if the image is blown out. No other mirrorless camera is this brain-dead.
LEICA SL2 + Leica 50mm f/2 Summicron-SL ASPH RAW: LACA corrected, distortion corrected
[low-res image for bot]
