What is HDR in games? Nits, DisplayHDR and when to turn it on

Your screen's peak brightness600 nits

Game's "max brightness" setting600 nits

Brightest pixel-

Detail in the sun-

Detail in the cave-

Simplified model for learning, not a measurement. Drag your screen's peak up and down. Then set the game's max brightness far above what the screen can do and watch the sun's rings melt into a flat white disc.