Originally Posted by Kris Deering
It is true that by selecting a color profile that is meant for the Panasonic, you are using a fixed curve. But this means that you have to adjust the slider in the Panasonic based on the dynamic range needed for the content as the Panasonic does not adjust its overall range on a title by title basis, it simply changes the tone map to the MaxCLL (if present). If you instead select the Auto tone mapping in the JVC and leave the Panasonic alone, the JVC will always map appropriately to the MaxCLL that is fixed from the Panasonic, but it will also adjust its overall range based on the changing MaxFALL data (again, if present). So now you have two dynamic features (MaxCLL and MaxFALL) at work. This tends to give the best results overall of the two options.
Am I deceiving myself when I find that the HDR presentation is superior in my HT by leaving the UB820's Optimizer at +4 and the overall slider for JVC Auto Tone Mapping at +3? It's an easy task to observe the different combination of tone values that the JVC creates based on the fixed MaxCLL of 500 nit and varying (content related) MaxFALL nit and I've found that the HDR results are far more plug & play with both devices enabled.
Here's a comparison of values for Netflix's "Altered Carbon" with various combinations on my UB820/NX7 and ATV4K
(MaxCLL/ MaxFALL/ Picture Tone/ Dark Level/ Bright Level)
Optimizer enabled/Auto Tone (500/ 356/ 3/ 0/ 6)
Optimizer OFF/Auto Tone (1149/ 356/ 2/ 0/ 0)
Optimizer enabled/Panasonic HL curve (500/ 356/ 4/ 0/ 0)
Optimizer OFF/Panasonic HL curve (1149/ 356/ 4/ 0/ 0)
/Auto Tone (10000/ 2496/ 0/ 0/ 0) Image far too dark
Similar observations are apparent with HDR on a UHD disc ("The Shallows"):
Optimizer enabled/Auto Tone (500/400/3/0/6)
Optimizer OFF/Auto Tone (1933/709/0/0/0)
Optimizer enabled/Panasonic HL curve (500/400/4/0/0)
Optimizer OFF/Panasonic HL curve (1933/709/4/0/0)
It seems obvious that there's no difference in the slider controls when using the Panasonic custom curve, irrespective of the state of the Optimizer, but there is a difference in these sliders for Auto Tone mapping which varies with the MaxCLL. Several months ago there was a brief back-and-forth conversation (either on this thread or the UB820/9000 owners' thread) regarding whether it or not was advantageous to provide the JVC with a lower MaxCLL for the purpose of utilizing Auto Tone mapping. Is this advantage apparent with the different JVC slider controls seen with both devices' tone mapping enabled?