Zamundaaa

For Netflix there's a browser extension that does it, but I don't know of a solution for other streaming services

Quite the opposite, bigger grids are much more stable. When faults happen, tiny subsets of the grid get disconnected from the rest, it does not take the whole thing down at all...

Yeah, it gets more blown out the bigger the difference between the sdr brighrness setting and the highlights is.

Support for HDR screenshots is hopefully something I can add soon-ish

How are you taking the screenshots? Spectacle might not capture HDR highlights well, but it should look all proper on SDR content

Also, your blog is fantastic, I'm always happy when there's a new post =)

Thank you, I'm glad you like it!

I feel like in SDR mode, the OLED is pushing brighter images. I almost feel like it's underselling the capabilities at 270, but does so to give pixels a rest every now and then, in the hope that the bright spots don't stay stationary on the screen. It's a wild guess, I have no idea.

It's certainly possible, displays do whacky stuff sometimes. For example, if the maximum brightness in the HDR metadata matches exactly what the display says would be ideal to use, my (LCD!) HDR monitor dims down a lot, making everything far, far less bright than it actually should be.

KWin has a workaround for that, but it might be that your display does the same thing with the reported average brightness.

That's not really a Wayland thing, that's an (apparently badly implemented) attempt to bridge X11 apps to a permission system they were never written for.

With appropriate sandboxing of apps so they can't just LD_PRELOAD code into all other apps you run, yes.

I understand that it's an absolute brightness standard, not like the relative levels in SDR

The standard is also relative brightness actually, though displays (luckily) don't implement it that way.

why does it end up washing out colors unless I amplify them in kwin? Is just the brightness absolute in nits, but not the color?

It depends. You might

• have a driver bug. Right now only AMD has correct color space communication with the display, that doesn't work correctly on Intel and NVidia yet
• have a display that does a terrible job at mapping the rec.2020 color space to the display
• be just used to the oversaturated colors you get with the display in SDR mode

Why does my screen block the brightness control in HDR mode but not contrast?

Because displays are stupid, don't assume there's always a logical reason behind what display manufacturers do. Mine only blocks the brightness setting through DDC/CI, but not through the monitor OSD...

Why is my average emission capped at 270nits, that seems ridiculously low even for normal SDR screens as comparison

OLED simply gets very hot when you make it bright over the whole area, the display technology is inherently limited when it comes to high brightness on big displays

Multi monitor VRR has never been problematic in Wayland, but the NVidia kernel driver doesn't support it at all yet, Xorg or Wayland doesn't matter.

enabling the built in color profile desaturates colors quite a bit and does some kind of perceived brightness to luminosity mapping that desaturates bright / dark hdr content even more

It maps the colors to be more correct, and it does use the brightness info from the EDID for HDR content, so that checks out.

I think there must be something wrong with my screen since the hdr reduces saturation more than anything else

It might enable some sort of gamut mapping on the display side... HDR on monitors is really weird sometimes.

Side note, when I turn off hdr only from kscreendoctor the display stays in hdr mode until it turns off and on again, that didn't happen with nvidia

I think that's a bug in amdgpu. It should force a modeset on hdr change, but it doesn't.

That has pretty much nothing to do with the color profile, when colors look very desaturated on HDR screens, that's the driver messing up the colorspace signaling.

What GPU do you have? Both Intel and NVidia still have major problems with this.

Many displays (but not all, which is why it's not exposed in the GUI) also support doing HDR without additional colorspace signaling, you could try enabling only hdr and disabling wcg with kscreen-doctor. IMO the color part is the more noticeable benefit of HDR, but you could at least have functional HDR until your GPU driver is fixed.

Of course apps can and do restore their window sizes. Don't spread misinformation