What is HDR, anyway?

As a photographer, I get the appeal of (this new incarnation of) HDR content, but the practical reality is that the photos I see posted in my feeds go from making my display looking normal to having photos searing my retinas, while other content that was uniform white a second prior now looks dull gray.

It's late night here so I was reading this article in dark mode, at a low display brightness - and when I got to the HDR photos I had to turn down my display even more to not strain my eyes, then back up again when I scrolled to the text.

For fullscreen content (games, movies) HDR is alright, but for everyday computing it's a pretty jarring experience as a user.

Completely agree. To me, HDR feels like the system is ignoring my screen brightness settings.

I set my screen brightness to a certain level for a reason. Please don’t just arbitrarily turn up the brightness!

There is no good way to disable HDR on photos for iPhone, either. Sure, you can turn off the HDR on photos on your iphone. But then, when you cast to a different display, the TV tries to display the photos in HDR, and it won’t look half as good.

> To me, HDR feels like the system is ignoring my screen brightness settings.

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, that's the singular purpose of HDR to be honest. All the other purported benefits of HDR are at best just about HDR video profiles and at worst just nonsense bullshit. The only thing HDR actually does is allow for brighter colors vs. SDR. When used selectively this really enhances a scene. But restraint is hard, and most forms of HDR content production are shit. The HDR images that newer iPhones and Pixel phones are capturing are generally quite good because they are actually restrained, but then ironically both of them have horrible HDR video that's just obnoxiously bright.

"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.