I had posted the below information regarding Dynamic Contrast in the Panasonic UB-820 thread, but thought it would be useful here as well. I recently found the details on the Dynamic Contrast settings from ChromaPure's web site. If ChromaPure's information on the settings are somehow not correct, please let me know.
Dynamic contrast, while poorly named, is an active HDR tone mapping feature that allows the TV to provide dynamic metadata for HDR10 content. Dynamic Contrast analyses HDR10 content on a frame by frame basis in real time, to determine metadata for the scene and adjust the HDR tone mapping curve to match the content.
By design, HDR10 only uses the Maximum Content Light Level (MaxCLL) level for the entire program, based on the contents’ metadata information. The Dynamic Contrast feature complements and improves the display of HDR10 source material with more granular content analysis, similar to Dolby Vision. This feature is active when the setting is “Low”.
Control of this ‘Active HDR’ feature is found in the ‘Dynamic Contrast’ setting in the Expert Picture Settings menu, while viewing HDR content. The Dynamic Contrast settings are defined as follows:
• Off - Active HDR Disabled / Contrast Enhancement Disabled
• Low - Active HDR Enabled / Contrast Enhancement Disabled (default setting)
This is the setting recommended for accurate content reproduction.
• Medium - Active HDR Enabled / Contrast Enhancement Low
• High - Active HDR Enabled / Contrast Enhancement High
LG renamed this feature to “Dynamic Tone Mapping” for the 2018 OLED models.
The LG B7 series “Dynamic Contrast” tone mapping and the Panasonic UB-820 “HDR Optimizer” tone mapping are complementary
. Set Dynamic Contrast to LOW in the LG panel to enable its active HDR and use the HDR Optimizer in the Panasonic player with HDR output, and the display type set to “OLED”. The UB-820 will convert content mastered greater than 1,000 nits to the 1,000-nit range better than the 2017 LG, and then the LG will adjust frame by frame within that 1,000-nit range to best use its own dynamic range for video. Below is an explanation of how the HDR Optimizer works.
HDR Optimizer 101
The Panasonic UB-820’s HDR Optimizer feature performs tone mapping based on the actual Maximum Content Light Level (MaxCLL) for the entire film and the maximum nit capability of the type of display selected. The MaxCLL is contained in metadata on the disc for the given film, and the display maximum nit capability is selected based upon the display setting. For example, when HDR optimizer is set to “HDR”, and the display is set to “OLED”, the Maximum Display Mastered Level (MaxDML) reported to the display is 1000 nits, and the UB-820 performs the tone mapping based on the MaxCLL disc metadata for a 1000 nit display.