Originally Posted by matpal
Can you tell by the meta data that it is even doing tone mapping at all? This was my concern that the unit was not tone mapping any of it's streaming apps.
Do we know for sure if it tone maps the internal Netflix and YouTube app for HDR/UHD content?
I was doing A/B switching between streaming content with Roku and then the Panasonic apps... Exact same content and there was no appreciable difference when I would think the stuff streamed from th panasonic should look noticeably better.
I have an HDfury device connected after my UB820. The HDfury reports the HDR metadata received.
As an example, let's say the UB820 is set to HDR output with the Optimizer turned ON and HDR Display Type is set to OLED which represents 1000 nits. The HDR Optimizer will tone map the highlights that exceed 1000 nits in the content down to inside of 1000 nits. Before outputting the result, the Optimizer then replaces the original metadata with new values. MaxDML (Maximum Display Monitor Luminance) would be modfied to 1000 nits. MaxCLL (Maximum Content Luminance Level) would be set to a value less than or equal to 1000 nits depending upon the original MaxCLL value of the content.
When playing content from Netflix or Amazon with the UB820 in HDR output mode with the Optimizer turned ON, my HDfury reports that the original content metadata has been changed. So it leads me to believe that the Optimizer is indeed tone mapping. Otherwise, changing the metadata values alone without tone mapping could result in the HDR TV clipping highlights when it performed its tone mapping. This is my opinion, right or wrong.
When the UB820 is set to SDR/BT2020 output, I believe that the Optimizer is not used to tone map Amazon HDR to SDR/BT2020. For one, you can't access the Opimizer settings. They can only be accessed when playing a UHD disc. In addition, I came to this conclusion because I found that no matter what value I set the Dynamic Range Conversion Adj. slider when playing a UHD disc, it appears to have no effect on the brightness of Amazon content. Setting the slider to its maximum position makes UHD disc content too bright and washed out. Setting the slider to the minimum position makes UHD disc content too dark. But subsequent viewing of Amazon video HDR content after changing the slider value while playing a UHD disc looks the same in either case. So I believe the Optimizer is not used, and a default tone map is used to map Amazon HDR to SDR/BT2020. Again, my opinion only.
The reason you may not see a difference is so much of Amazon and Netflix content is mastered at 1000 nits and sometimes contains no metadata at all in which case a default 1000 nit tone map would be used by the Optimizer.. The Optimizer will perform less tone mapping in these cases than it would if MaxDML and MaxCLL metadata values were higher. If you set HDR Display Type to OLED (1000 nits) the Optimizer would probably not perform any tone mapping for 1000 nit content or content with missing metadata values.