ACES 2.0 CAM DRT Development

[priikone (Pekka Riikonen)]

@priikone

Regarding the ARRI bar image that was discussed in the meeting, where P3 shows “less detail” in the bottles than Rec.709, I think the gamut mapper could explain that difference. With Rec.709 there’s more out of gamut colors, and more compression will happen, and the lightness mapping that happens in the gamut mapper will map the color darker. With P3 it will compress less, and possibly doesn’t compress in that example at all. The gamut mapper doesn’t preserve the original luminance of the out of gamut color. I haven’t checked if this was the case.

I did check where the cyan-green bottle ended up going in P3 and Rec.709. The scene values are highly saturated. The only difference seemed to be that Rec.709 was just the more compressed value, and so also the less saturated one and also darker. The P3 was more saturated and brighter version of the color. Below 2D diagrams, but I looked this in 3D too, and I think it was clear to me the Rec.709 version was darker because it’s compressed more. But I guess, in this case, it’s supposed to be compressed more.

Input:

P3:

Rec.709:

Input EXR in dropbox