Hi Everyone,
We know how and why (to a certain degree) inverting ODTs can be problematic in some situations, but we’ve been able to take advantage of it in about 90% of our high end tv ads projects in the past (many) years.
After talking with a few color specialists, engineers, artists (…) it seems that none of us could find the ideal solution to the problem explained below.
I know there are a few color science experts (and scientists) around here, including @doug-walker (Hi Doug!) so I’m hoping this could be a chance to nail this one down for good
Dear experts friends, please chime in!
Cheers!
Mixed Color Spaces Problem
(display referred vs Scene referred)
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Goal
Mix sRGB or bt1886/rec709 with ACEScg and Camera Log sources, comp, render and deliver in ACEScg (client’s specs), without affecting any colors in any source (at least visually).
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Given Color Management policy/config
Syncolor (ACES1.1) in Flame 2023.3 and OCIO v2 vfx config (ACES1.3 ocio v2.1) in Nuke v14 and Maya/VRay.
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Constrain
Do not use any inverted view/display (Syncolor/ocio) transform.
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Problem
If you convert the sRGB texture to ACEScg using an input transform (Flame), you’ll need to look at it under a gamma corrected display (untoned map in OCIO).
If you convert a camera log file to ACEScg, or receive material in ACEScg color space, you’ll probably need to look at it under an ACES 1.0 SDR display transform.
How do you comp together 2 things that are meant to be viewed differently?
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Questions
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Is there a mathematically correct way to achieve this using ACES color science?
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If not, is our only option to indeed invert ODTs to convert display referred material when the visual output ‘looks’ correct and reacts nicely to additional post processing (grading …)?