sRGB (ACES) Display -- Shaping curves

[stephane.vogel]

Hi everybody,

I’ve noticed that in Nuke there’s a display “sRGB (ACES)” which is not similar to the classic sRGB display due to a Shaping curve. (as mentioned on this topic : https://community.foundry.com/discuss/topic/135319/can-t-reproduce-the-same-look-with-linear-srgb-renders-in-nuke-ocio-aces-config#1186591).

My question is, does everyone know where I can find the function of these curves ?

Thank you very much and have a good day !

[Thomas_Mansencal]

Hi Stephane,

• The sRGB EOTF and its inverse are defined in sRGB IEC61966 - 2.1 but you can find it online: https://en.wikipedia.org/wiki/SRGB
• The Output - sRGB transformation is more than a simple curve, and is the concatenation of many functions, entry point for it is here: https://github.com/ampas/aces-dev/blob/cda4c1a137207b2a6eb823039abe5524fa1c1335/transforms/ctl/odt/sRGB/ODT.Academy.sRGB_100nits_dim.ctl#L66 and it expects OCES values generated by the RRT here: https://github.com/ampas/aces-dev/blob/cda4c1a137207b2a6eb823039abe5524fa1c1335/transforms/ctl/rrt/RRT.ctl#L21

Cheers,

Thomas