Quote:
Originally Posted by Warner306
Were you trying to find a target nits that perfectly tracked BT.2390 all the way to 100% output? The only commonality I see is that the brightness does seem to get to white too slow or too fast at the top. Maybe that is something that is lost in translation with SDR? And maybe it is close enough?
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No, I want to work with measured nits but I am wandering why MadVR generated BT.2390 curve (as measured) drifts gradually (and significnatly) away from HCFR reference BT.2390 curve and then returns to being spot-on at 70% but then gets clipped at 80-90% stimulus if we know the "formula" is defined in the papers and should be the same in HCFR and MadVR. Is the 80-90% clipping part of the formula to mantain some HDR effect with low peak brightness?
If translation to SDR was the cause, I expect the PQ curve tracking would drift as well but it is not.
Quote:
Originally Posted by Warner306
That part don't make no sense. Only the 8-bit pattern should display correctly, but you shouldn't fail the black clipping test if you are clipping correctly to 175 nits. The gradient should go from right-to-left until Bar 16.
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hmm...there is no bar 16, there is a clip with 64-80 bars and there is a clip with C64-C111 gradient (0.0-0.07 nits). In the former I can, with great effort and in pitch black room notice that bars 76-80 are flashing, almost un-noticebly. In the gradient clip I can see the gradient becoming VERY slightly lighter, from left to right, than the bottom black part, so I am guessing there is no crush but also that near black gradation is so barely noticable - don't know if that's a problem and it should be more noticable.