Question about LG Oled65c8

Hello,
The TV has a function that adjusts the picture brightness (OLED brightness) to the ambient brightness. However, this can be switched off. Then the brightness stored in the selected picture option (e.g. cinema) is retained.

If the film is paused (e.g. in Netflix), the screen saver switches on after approx. 1 minute and the screen goes black. When the remote control is moved, the picture comes back and the film continues in its original brightness. The same happens when music is played via the internal media player or an installed app.

Personally, I haven't noticed any problems with dimming that would have affected the viewing experience. There are probably adjustments to the image brightness per image or frame as part of the HDR standards (Dolby Vision, I believe). However, this is intentional in the respective HDR standard in order to bring the best possible film experience to the TV, so it is normal.
The TV has a great picture, but is primarily worth it if you also have 4K/UHD sources and at best with HDR/Dolby Vision (e.g. Netflix UHD subscription) to get everything out of the TV.

Hope this helps.
Greetings