P3 color conversion to XYZ

Anything and everything to do with DCP-o-matic.
NominalFilm
Posts: 3
Joined: Thu Aug 10, 2023 6:27 pm

Re: P3 color conversion to XYZ

Post by NominalFilm »

Dear Carsten, thank you very much for your feedback and the suggestion to try a custom conversion preset. Your solution sounds plausible and I will try it out. As soon as I have results I will let you know. Thanks again and all the best, Max

PS: it will take some time (about 1-2 weeks)
RAY-NUE
Posts: 92
Joined: Mon Aug 21, 2023 4:18 am
Location: Ratchaburi, Thailand

Re: P3 color conversion to XYZ

Post by RAY-NUE »

Carsten wrote: Tue Aug 29, 2023 11:50 am That's not true, P3 was there long before any HDR technique was available. And essentially all DCI projectors use P3 and are not HDR10 capable (with some rare exceptions).
P3 and HDR10 There is a matching color space that overlaps.
P3 for cinema, HDR10 for home use
HDR10-capable monitors can be used to check P3 color output.
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Carsten
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Location: Germany

Re: P3 color conversion to XYZ

Post by Carsten »

That's a 'can', not a 'must'.

Also, Cinema uses a 14fL/48cd/sqm viewing environment, while HDR/HDR10 devices will usually exhibit much higher peak luminance values and can usually not be tamed down to 50nits.

- Carsten
RAY-NUE
Posts: 92
Joined: Mon Aug 21, 2023 4:18 am
Location: Ratchaburi, Thailand

Re: P3 color conversion to XYZ

Post by RAY-NUE »

Carsten wrote: Fri Sep 01, 2023 1:32 pm That's a 'can', not a 'must'.

Also, Cinema uses a 14fL/48cd/sqm viewing environment, while HDR/HDR10 devices will usually exhibit much higher peak luminance values and can usually not be tamed down to 50nits.

- Carsten
As important as brightness is color distortion.
NominalFilm
Posts: 3
Joined: Thu Aug 10, 2023 6:27 pm

Re: P3 color conversion to XYZ

Post by NominalFilm »

Hi Carsten, I tried your suggestion, haven't seen it in the cinema yet, but it looks good in a DCP player on a monitor. I'm just wondering, does this mean that the P3 setting in DCP-o-matic assumes a "Display P3" (with D65 white point and sRGB gamma curve)? Best regards, Max
Carsten
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Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: P3 color conversion to XYZ

Post by Carsten »

No, DCP-o-matic's P3 color conversion matrix currently interprets the SOURCE file as having been monitored/graded on a DCI whitepoint display (~6300K).
Which COULD have been the case, but in general, I guess that P3 displays/calibrations use the Display-P3 whitepoint/6500K.

I guess that Carl should correct the default P3 conversion to cater for P3-6500 source files. The x'y'z' conversion then will transfer the 6500K based content towards the DCI whitepoint, which should match the P3-6500 monitoring closer than it does now.