XDR upscaling brightness decreases somewhat when bright content appears - why? about betterdisplay

[waydabber]

Hi there, this is because at certain brightness levels the panel uses a technique called ABL (automatic brightness limiter) to limit brightness - when the screen reaches its defined power limit, the controller automatically decreases its brightness to compensate. When XDR upscaling is used and the screen contains mostly bright elements and all mini-LEDS output at full power, this limitation kicks in on M1 and M2 MBPs (and to certain extent M3 MBPs as well even though these have more energy efficient LEDs).

If you are using a mostly bright/white desktop, you might not want to crank up XDR upscaling all the way to max. If you use native XDR upscaling, you can limit max slider brightness to around 1200 nits on the M1 MBP to avoid this issue.