Follow-up from "Color: Improve wording and minor fixes"
The following discussion from !10 (merged) should be addressed:
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@swick started a discussion: (+1 comment) I'm not sure if I like this. In the following sentences you go on and say that SDR maximum white is not necessarily 80 cd/m^2 so why say this in the first place? The SDR maximum white is whatever your monitor gives you in SDR mode.
@pq replied:
Because it's different depending on whether you are looking at content or an output. It does say "reference luminance".
Content that actually cares about nits should always use the value 80 nits for maximum SDR white.
For outputs, the maximum SDR white can be whatever, but if the end user actually wants to follow the nits the content suggests, they need to adjust monitor brightness knob and/or output EDR so that SDR maximum white is 80 nits.
The point is that we allow arbitrary viewing conditions by allowing output EDR value to decouple nits from content, but when desired, it is still possible for the end user to adjust his monitor and compositor (output EDR) such that the actual nits from content are delivered as his monitor permits.
Is this a solid idea? I can work on the wording to get this through better in the spec, and it will be obvious from
color.rst
once I get to writing it.