Need for "technical" Look Transforms

[scottdyer]

It would be useful to have Look Transforms (or some other mechanism, if more appropriate) to help users work in ACES 2 but with some of the expectations they have developed under ACES 1. These might be individual transforms or there may be one transform which helps address a few of the noted complaints. Some specific needs that have been collected:

• "Finished" look: adjust default output of ACES 2 so it appears more “finished” than ACES 1.
• "Contrast" look: adjust the ACES 2 tonescale contrast to better match that of ACES 1.
  • An exact match is probably not necessary, but should provide more mid-slope contrast and more of a corner in the highlight rolloff to white
• Hit max sooner: ACES 2 requires a linear value of 128 to reach max (vs ~16 in ACES 1)
• Raise luminance of middle gray: Set middle gray (and overall brightness) higher
  • Historical aim for SDR is 0.18 of ~0.1 in display linear is valid but applicable for traditional film workflows in dark environment. But many users are applying ACES in other contexts, such as web browsers, video games, or on screens where the environment is very different. ACES defaults have always been viewed as too dark for these uses, but in ACES 2, images can appear even darker due to the more gradual highlight rolloff.