Technical ODTs

Tags: #<Tag:0x00007f0dd3148808>

As explained in this post:

all ODTs clip black levels, this is very bad when doing QC on a key or on grain/artifacts.

(RRTODT dont do this btw)

We just had this come up, and I am sure we are not the only ones having an Issue with this for doing technical work.

It seems like its all down to the Cinema Black value in the
ACESlib.ODT_Common.ctl
const float CINEMA_BLACK = pow10(log10(0.02)

If Id known how, I would just get rid of the whole thing and make new shaper luts to use instead in a custom ocio without any cinema_black (or cinema_black=0) .

The ACESlib.OutputTransforms.ctl
has no mention of CINEMA_BLACK hence the RRTODTs dont clip the blacks, there just arent any srgb/709/p3 SDR RTRTODTs…

I understand it might be for some reason desirable to clip the blacks… but we dont need that for working.

Anyone has a solution? custom ODT? Custom RRT+ODT?

I can make a own 3D Lut that would do this from acesCC(t) to sRGB/709/P3 but I would rather have a proper inversible tranform.