Why RRT/ODT sRGB makes the look darker?

Discussions - Using ACES
2

Hi @Vincent_Gires,

This is a good question and here are a few answers:

  • The ACES RRT was designed for Theatrical Exhibition where Viewing Conditions are Dark. Content for cinema tends to be authored with more contrast to compensate for the dark surround.
  • Even though there is a surround compensation process (Dark <–> Dim), the values to drive that process were subjectively obtained and it might not be enough for all the cases.
  • The RRT + ODTs are also the results of viewing images by an expert viewer, so there undeniably some subjectivity built-in.
  • Your current Viewing Conditions might not be that expected by the ODT you are using, are you under Dim ones?
  • Some companies such as Epic Games are pre-exposing the Scene-Referred Values with a 1.45 gain.
  • We touch a lot of that in the ACES RAE paper: ACES Retrospective and Enhancements

Hope this helps! :slight_smile:

Cheers,

Thomas

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