There are 2 gammas at work in the shader, input gamma and output gamma. You can’t change output gamma though as this is bound to the output color space. If you are in a dim to bright surround sRGB is fine, if you are in a dim to dark surround 709 is more appropriate, and if you are in a dark surround and have the gamut to spare DCI-P3 (2.6 gamma) is even more appropriate.
The input gamma is also stuck at 2.40 (the // OETF line) as this is how the gamma is encoded in the image (no developer confirmed how they extract gamma encoded colors, so sRGB assumed).
The gamma_in value exposed is a bit on the artistic side. Really it should only be 2.222 for Composite, or 2.522( 2.40 with the offset) for RGB. Other than that it’s an artistic contribution to the monitor gamma which as we know it varied a lot in practical terms, so it’s ok to run this out of spec.
There are 2 LUT entries the first is for artistic purposes, the second is designed more for color management. You calibrate your monitor, then use the second LUT entry with a HALD CLUT to color manage Retroarch. For example in my case I calibrated to sRGB, process everything in sRGB and use a (sRGB) LUT on the second entry. You can calibrate to DCI, process everything in DCI and also use a (DCI) LUT on the second LUT entry.
I’m not sure about the phosphor’s gamut, haven’t checked if they fall within sRGB. But having a wide gamut always helps whatever color work you do.
Obviously im doing something wrong… lol
