A bit of a ramble.... but AFAIK, there are two parts to the compromises that may need to be made to watch "HDR" content like that found on UHD BD:
- HDR: ability to show an expanded luminance range (both with lower black level details well under 0.1nits and currently as high as 10,000 nits) than SDR (traditionally only encodes from 0.1 to 100nits)
- Colour Space: ability to cover a wider colour space (say 2020, DCI-P3) than 709. Note: you can have an SDR display with DCI-P3 coverage and accept a 2020 signal (aka 2020 SDR which is a "thing")
As we don't have domestic screens that can do 10,000 nits or cover a 2020 colour space we have to compromise on both aspects, and hence the work Hendrik is doing.
My thinking was that as a lot of UHD content has been mastered to DCI-P3 (in a 2020 wrapper) and max 1000nits;
- Use Passthrough with screens like my Phillips (DCI-P3 Coverage: 97.6%, DisplayHDR 1000 and UHDA certified),
- Tonemapping for the PJ and
- ?? for the OLED.
So to check what content I actually have, I ran SOT over my 250 odd UHD BDs and populated MC with the values for,
Color range: 100% were "Limited"
Color primaries: 3 were BT.709 and the rest were BT.2020
Transfer characteristics: 3 were BT.709 (same discs as above) and the rest were PQ
Matrix coefficients: 3 were BT.709 (same discs as above) and the rest were BT.2020 non-constant
Mastering display color primaries: 13 were BT.2020 and the rest were Display P3
Mastering display luminance: 103 had a max of 4000, 2 had a max of 1100, the rest were 1000
If I'm reading these tags correctly, it looks like 40+ % are mastered for 4,000 nits and 5% with a full BT2020 colourspace.... so tonemapping will still be needed (either JRVR or the displays in built tone mapper) and will be for sometime regardless of the display.
Anyway.... as I've now got this metadata into MC it could even potentially setup Zones based the Luminance Values / Color Primaries to switch between Tonemapping and Passthrough depending on the content.
To answer an earlier question is I'm trying out leaving OS HDR ON to prevent the display change that happens and let Windows Tone Map UP the Desktop and SDR content to HDR to the Display that is running in HDR. So far it seems to work pretty well and everything just looks "correct" (I guess it is easer to map up SDR to HDR levels than the other way around)..... but this is all a new concept.