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Discussion Starter #1
Those who have calibrated recent Sony TVs may have observed that DoVi Dark mode shifts the white point and introduces a yellow cast. (I own a X950H.) This has also been shown on certain YouTube review videos.

I have a hypothesis, and would like Sony owners and experts to weigh in.

Recall that Sony calibrates at the factory to a Judd modified white point, CIE1931 equivalent x0.3067 y0.3180. I’ve measured out of the box and verified it’s close to this. Typically, one would just recalibrate SDR to D65 or one of the AWPs posted on this forum. As designed, the TV uses that calibration to derive HDR10 and DoVi picture outputs. This is where the white point shift is introduced on DoVi Dark.

I couldn’t understand what Sony was trying to achieve here. Then I remembered the factory Judd white point, and guessed that the intent was for DoVi to be derived from this. So with the factory white point as the base (or calibrated more precisely to x0.3067 y0.3180), I checked what DoVi Dark would do. Surprise - the resulting DV white balance was near D65.

Does this sound plausible to anyone? Or just a coincidence? For now, it’s a convenient solution to the DoVi white point issue. I reserve one color temp to calibrate to the Sony WP, or leave it at defaults if not using the universal 2-pt gain settings.
 

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Those who have calibrated recent Sony TVs may have observed that DoVi Dark mode shifts the white point and introduces a yellow cast. (I own a X950H.) This has also been shown on certain YouTube review videos.

I have a hypothesis, and would like Sony owners and experts to weigh in.

Recall that Sony calibrates at the factory to a Judd modified white point, CIE1931 equivalent x0.3067 y0.3180. I’ve measured out of the box and verified it’s close to this. Typically, one would just recalibrate SDR to D65 or one of the AWPs posted on this forum. As designed, the TV uses that calibration to derive HDR10 and DoVi picture outputs. This is where the white point shift is introduced on DoVi Dark.

I couldn’t understand what Sony was trying to achieve here. Then I remembered the factory Judd white point, and guessed that the intent was for DoVi to be derived from this. So with the factory white point as the base (or calibrated more precisely to x0.3067 y0.3180), I checked what DoVi Dark would do. Surprise - the resulting DV white balance was near D65.

Does this sound plausible to anyone? Or just a coincidence? For now, it’s a convenient solution to the DoVi white point issue. I reserve one color temp to calibrate to the Sony WP, or leave it at defaults if not using the universal 2-pt gain settings.
The reason for the shift with DV is the DV engine wants and uses DCI-P3 (correction). With the newer Sony's using TV Led DV you can now measure and see this. It doesn't mean you can't use an alternate WP for DV and calibrate it separately using another color space. The problem is the DV engine is a black box to the manufacturers, just the way it is and will probably stay this way.
 

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The reason for the shift with DV is the DV engine wants and uses DCI-P3 (correction). With the newer Sony's using TV Led DV you can now measure and see this. It doesn't mean you can't use an alternate WP for DV and calibrate it separately using another color space. The problem is the DV engine is a black box to the manufacturers, just the way it is and will probably stay this way.
Yep just like we discussed last week. This is also not exclusive to Sony displays. I’ve also seen this on LG displays.... specifically when it is receiving a Player-led DoVi signal. PITA to fix on the 2020 (minus the 900H) and prior Sonys but easier to correct on the 2021 Sonys and LGs of course.
 

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Does this sound plausible to anyone? Or just a coincidence? For now, it’s a convenient solution to the DoVi white point issue. I reserve one color temp to calibrate to the Sony WP, or leave it at defaults if not using the universal 2-pt gain settings.
It sounds plausible to me, but did you check if the default settings look like what you would get for the Sony WP, if you calibrated to that (I know most think the Sony WP doesn't make sense to use) in SDR? Then it would make even more sense that DV is based on this assumed starting condition.
I am interested as I am likely getting one of the Sony LED LCDs soon.
 

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It sounds plausible to me, but did you check if the default settings look like what you would get for the Sony WP, if you calibrated to that (I know most think the Sony WP doesn't make sense to use) in SDR? Then it would make even more sense that DV is based on this assumed starting condition.
I am interested as I am likely getting one of the Sony LED LCDs soon.
I first checked the default settings (basically no adjustment to 2-pt and multi-pt RGB balance), it was close to Sony’s CIE1931 x0.3067 y0.3180, within 0.002 in x-y.

Once I calibrated to the Sony WP in SDR, Dolby Vision Dark WP was within 0.0015 (average x-y distance) of D65. This is true of internal apps (TV-led DoVi) and HDMI (player-led) for my TV.

It’s possible what jrref said for OLED is different for LCDs. And it will be interesting to see once we get reports from the new 2021 LCDs, if anything changes.
 

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I first checked the default settings (basically no adjustment to 2-pt and multi-pt RGB balance), it was close to Sony’s CIE1931 x0.3067 y0.3180, within 0.002 in x-y.

Once I calibrated to the Sony WP in SDR, Dolby Vision Dark WP was within 0.0015 (average x-y distance) of D65. This is true of internal apps (TV-led DoVi) and HDMI (player-led) for my TV.

It’s possible what jrref said for OLED is different for LCDs. And it will be interesting to see once we get reports from the new 2021 LCDs, if anything changes.
Yes, your post is the only one I saw reporting on this initial vs. post calibration with respect to impact on DV, for OLED or LCD. Interesting.
 
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