That’s very interesting Jed.
Having little experience with HDR (unfortunately), I think these examples help a lot ! I agree that these images show clearly that the hue shifts/skews will be dependent of the RGB (per-channel) lookup “compression”.
It reminded me of this paper (originally shared by Kevin Wheatley). Quoting the conclusion :
The maxRGB variation is the only implementation, out of the five presented in this article and summarized in Table 5, that accomplishes both objectives [restricting luminance and minimizing hue variance].
And this makes me wonder how this could be solved in the current ACES Output Transform (for the possible prototype’s evaluation). If I recall correctly, it has been stated a couple of times that this would be very tricky to correct for.
Because if it is device/display dependent, doesn’t it beat the whole idea of color management ?
Best,
Chris