Comment by frollogaston
3 days ago
"On both Android & iOS/MacOS it's not that HDR is ignoring your screen brightness, but rather the brightness slider is controlling the SDR range and then yes HDR can exceed that"
Doesn't this mean HDR is ignoring my brightness setting? Looking at the Mac color profiles, the default HDR has some fixed max brightness regardless of the brightness slider. And it's very bright, 1600 nits vs the SDR max of 600 nits. At least I was able to pick another option capping HDR to 600, but that still allows HDR video to force my screen to its normal full brightness even if I dimmed it.
> Doesn't this mean HDR is ignoring my brightness setting?
Not exactly because it is still being scaled by your brightness setting. As in, start playing an HDR video and then mess with the brightness slider. You will still see the HDR content getting dimmer/brighter.
It's easier to think about in Apple's EDR terms. 0.0-1.0 is the SDR range, and the brightness slider is changing what the nit value is of "1.0" - is it 100 nits? 300 nits? 50 nits? etc... HDR content (in theory) still has that same 0.0-1.0 portion of the range, and it's still being scaled. However it can exceed that 1.0. It's still being scaled, it's still "respecting" that slider. Just the slider wasn't a brightness limit as you're wanting it to be, but a 1.0 alignment point.
The problem comes when HDR content is disrespectful to that. When it just absolutely slams the brightness, pushing all of its content way past that 1.0 value. This is bad content, and unfortunately it's incredibly common in HDR media due in part to the fact that the original HDR specs are very incomplete and in part because it's a new loudness war.
Ah, just tested with https://github.com/dtinth/superwhite and you're correct. I remember it not even scaling with the brightness, but guess I was wrong.