Found another bug/quirk of the HDR Optimiser. I was watching Superman III on UHD and seeing if I could tame the brightest, smallest speculars which run well over 3000 nits, indeed, the MaxCLL metadata shows 3200+ nits. Toggled the Optimiser on and off (set to Medium/High a.k.a. 1000 nits as the tone mapping threshold) and it's not doing anything. Literally nothing. Huh.
The highlight detail isn't clipped in the source, as when I adjust the contrast I can bring out the speculars that are being clipped by my ZD9 TV (which tops out at 1800 nits calibrated and clips what's above that). So what gives? Well, while the disc's MaxCLL is 3200+ nits, the mastering display metadata is only at 1000 nits, so even though the Optimiser is supposed to look at MaxCLL first, mastering display second, whichever is greater, it seems to be verr confuse that the mastering display level is *lower* than the MaxCLL. That the former is set to 1000 nits would explain why the HDR Optimiser isn't doing anything when set to Medium/High (1000), as it doesn't think there's anything else there. When set to Basic (500 nits) then it does map it down a little, but only what's present between 500 and 1000 nits in the signal, as it still thinks it's only got 1000 nits as the maximum there, so the speculars are still clipped.
This is another reason why I could never, ever leave the Optimiser on all the time and be confident I was always seeing a properly mapped version, feels like I'm always having to second guess it whereas at least with my TV's limitations I know exactly where they are and what they do.
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