Camera Raw: Fails to load S-LOG2 data from Sony A7S ARW files

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BUG: Camera RAW Editor fails to load S-LOG2 data from Sony A7S ARW filesREPRO: 1. Shoot image with A7S in PP0 (Picture Profile 0)2. Preview Image in Bridge/LR/PS or Directly in Camera RAW3. Validate image appears to match what was shot and is displayed on camera LCD Screen4. Switch PP mode to PP7 (S-LOG2 mode)5. Shoot image with A7S6. Preview Image in Bridge/LR/PS or directly in Camera RawEXPECTED:Image thumbnail/preview/or loaded file via RAW editor matches flat image that is displayed on screen, or which is rendered by Sony's Image viewer for the A7S.ACTUAL RESULTS:S-LOG2 data containing dynamic range content is lost upon load into Camera RAW presenting a very dark image in the RAW editor which also appears grainy. Image will exhibit digital distortion of pixels during editing due to missing bit data.Sony Image Viewer also exposes additional attributes not surfaced via the Adobe RAW plugin in such as 3:2 Crop. By default thumbnails and images ingested by PS/LR/Bridge and CR directly are cropped by default, resulting in several hundred pixels removed from the top and bottom of the image. 3:2 exposes all pixel data from the square full frame sensor.Additional information about this bug can be found in my support chat log. REFERENCE #0186685332ARW File: https://www.dropbox.com/s/k0baroq6zxj...
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Bosley Beats

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  • excited (new bug)

Posted 3 years ago

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Bosley Beats

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*bump for visibility
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Bosley Beats

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*Bump* Checked in CC2015 update, this is still an issue in which the RAW editor does not properly load/process RAW+S-LOG2 files properly.
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Steve Sprengel, Champion

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Downloading and reviewing your ARW file, I think the crop behavior is acting how it is designed.

Specifically, looking at the camera-embedded preview, it is HD Video aspect ratio 1920x1080. Adobe is cropping the raw data by the same ratio by default. You can override this camera-aspect-ratio crop and reveal all the sensor data. I don't think the fact that Adobe tracks the camera's custom crop setting is a bug.

Regarding SLog2 data. Adobe doesn't promise to perform custom camera operations it uses to produce the JPG. Adobe only works with the raw data and the white-balance data using it's own raw converter with it's own settings.

Since you only provided one of the two files, either step 1 PP0 or step 5 PP7, it's hard to know whether the Adobe software is performing as expect or not. As expected would be that the dynamic range of the PP0 and PP7 raw file data would be similar, although one might be darker or lighter depending on whether the camera is purposely changing the exposure and then applying some custom luminance curve to produce the JPG.

Modes like Nikon Auto Dynamic Lighting (ADL) or Canon Highlight Tone Priority (HTP) do exposure tricks and custom curves to produce the camera JPGs. It is not a bug that Adobe can't reproduce these proprietary operations.

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Bosley Beats

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Thanks for the outreach Steve, Appreciate it. I've uploaded some additional files for you to A:B compare.

DSC02782.ARW -- Shot in PP7
DSC02783.ARW -- Shot in PP0
DSC00027.ARW -- Shot in PP7
SonyRaw-AdobeRaw.png -- A:B of Raw viewer shipped with A7S which loads S-LOG2 Data, revealing flat grey image

https://www.dropbox.com/sh/5omfnd1qux...
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Steve Sprengel, Champion

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Is the SLOG2 data in a separate raw file that has 5 extra bits of raw data for every pixel position to make the ISO 3200 down to ISO 100 or is the SLOG data merely a curve recorded in the raw file?
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With the two mountain images, I can increase the Exposure to +0.95 for the PP7 and have a very similar histogram to the PP0 version.

Besides having a proprietary curve, the issue with the PP7 (S-Log2) version is that the minimum ISO of 3200, which will always make the raw data very grainy.

Your Sony camera and software are applying noise-reduction automatically to get a reasonably looking JPG for ISO 3200 but this will inevitably kill some detail.

I see no reason to use a proprietary camera mode that is always high ISO and uses a custom curve that Adobe can't know how is applied.
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Bosley Beats

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Hi Steve, thanks for continuing to investigate this issue.

You will be able to get a histogram match, but the image should have a very flat grey look to it. The A7S shoots phenomenal images at higher ISOs with a *different* type of grain. It's not the typical noise that i'm used to in either the 7D or 5D series, it actually looks like film grain.

The scenario me and my team are going for, is that we shoot S-Log2 video with the A7S or FS-7 and we want our time-lapses which are shot in Full Frame, 4K resolution to match our video profiles. We can apply a LUT (Light Lookup Table) in either Photoshop or AE for 35mm film emulation for ridiculously awesome output in colour correction. Currently we've found the LUTs from VisionColor (http://www.vision-color.com/impulZ/) to yield the best results from our research.

I'm uncertain how the ARW format stores this additional data for the RAW+S-Log2, I haven't started to reverse engineer the file to get to the nitty gritty of the details. I did try looking up the specifications of the file online; but no dice. :|

But overall, the goal is to leverage the cameras ability to capture still media in this mode, so it can match up accordingly to the 4K S-Log2 video output, thus getting most of the camera and allowing my team to have a consistent workflow process in post.

Is there a rep at Sony that you all typically deal with? I can strike up a conversation with them to get some more details about this file format and see if we can get some traction regarding exposing the proprietary data that is inaccessible to the Adobe Camera RAW and go from there.

When fully realised, this capability exposed by the A7S is pretty amazing and can lead to a new type of digital cinematic look when used in conjunction with the right set up light lookup tables in post.

Thanks again for your continued interest in this problem, your expertise has definitely help shed a light on how the inner workings of the Adobe RAW editor functions in relation to various RAW file formats.
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Bosley Beats

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One other comment -- I found this fellow's blog to be of interest with some good information about S-Log2 and the Sony camera system. Granted this article is talking about using S-Log2 w/ motion video rather than stills; it really goes into depth about the technology.

http://www.xdcam-user.com/2014/08/exp...
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sanata y clarificación

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Hi! I know this is 3 years old and highly doubt that you'll ever read this, but did you manage to solve it? I'm having the exact same problem, with some photos we shot using Sony A7S II. There's not much information over the internet. Thanks
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Jeffrey Tranberry, Sr. Product Manager, Digital Imaging

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What is your specific issue? Raw images are dark? See Steve's answers above.