sRGB issue with Blender/Nuke, Color Management Workflow

Discussions - Using ACES VFX
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Hello guys,

I wrote an lengthy post on my Blender/Nuke workflow but it didn’t get posted.

So I write a short version. In Blender I create a rendering with ACEScg. Importing it as EXR into Nuke and do my grading. Then I export it as “Output-sRGB” as tiff 16bit. If I reload the same file into Nuke that I just exported I get some minor differences in values probably due to the compression.

nuke
nuke1920×1038 812 KB

Nukes viewer process is automatically set to sRGB (ACES).

Now comes my issues that drive me a little crazy. I have a software calibrated monitor and the ICC profile is set in Windows Color Management. This is necessary to see accurate colors imho.

But this creates a pitfall at least on my end. Nuke seems to take into account that ICC profile in its viewer. If I export the picture and view it in the old Windows Image Viewer I get a slightly desaturated result. In the newer Windows 10 Photos App the picture looks the same as in Nuke. But when I take a picture of the same file opened in two seperate windows side by side you can still see the difference here in one picture:

interesting
interesting1920×1009 1.16 MB

How does that make any sense?
I then take another screenshot of both viewers. First the less saturated one:
more saturated
more saturated1900×1106 1.31 MB

Here the more saturated one:
less saturated
less saturated1900×1106 1.46 MB

Another thing I noticed is that when I take a screenshot of Nuke and then open it in Photoshop the picture is also less saturated. If I set the Color Management in Photoshop to my ICC profile of my calibration I get what I see again.
But I gets worse. If I set Photoshop back to sRGB and open my earlier saved screenshots they still show a difference in color saturation. SO somewhere along the way color information gets lost. Here I loaded both screengrabs inside Nuke again with Output-sRGB. You can see the values in the less saturated version are off.
screengrabs
screengrabs1920×1041 809 KB

This is very complicated and I hope someone has insight into this issue.

Greetings
monitorhero

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Welcome! Thanks for this post. Initial posts need to be approved, but you should be good now.
Looking forward to seeing what people say!

Steve T
ACESCentral Admin

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Hello Steve,
sorry I realized that after writing the second thread. I must have missed the approval message the first time :).

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Hello @monitorhero,

I wish I could help but I am not at all familiar with ICC workflow and Windows. I hope you’ll find a solution quickly.

Chris

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Troy Sobotka was nice enough to help me out and apparently the Windows Color Management is less than ideal. Maybe I have to switch to Mac for this or build myself a Hackintosh. However I have been doing this work on a laptop but I also own a hardware calibrated monitor with a 3DLUT. That might help me to emulate sRGB mode and circumvent the whole Windows Color Management and ICC profiles.

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Hi,

Nuke entirely bypasses the ICC profile of your display while Photoshop will honour it. Put another way, your display is “not calibrated anymore” when seen through Nuke. The industry standard and only solid solution I can recommend to that problem is that we use in the VFX industry: Displays with Hardware LUT.

It is possible to create a custom matrix with a custom tonecurve for a custom OCIO colourspace for your display but it is quite involved.

Cheers,

Thomas

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Ha. Just what I wrote :D. Thanks for the response Thomas. I will get back to you if I find a good solution.