Just trying to get some answers before I possibly make a bug report about this. I noticed that when in HDR mode, the brightness transitions are nice and smooth, but for regular monitors the brightness shifts starkly once I let go of the bar on the brightness widget.
I’m curious to know if smooth brightness transitions are only possible because of how HDR is implemented vs. brightness controls on normal monitors? I’d like it if all my monitors were capable of smoothly increasing and decreasing brightness.
It is not a bug it’s a feature.
Hardware (DDC/CI) vs. Software (OS only) brightness control.
From how I understand it, basically with Hardware brightness switching, usually the “default” for SDR monitors, the brightness value is stored in your monitor and that memory has only a finite number of writes (don’t known maybe 100000 or 1000000 change cycles) depending on the IC manufacturer until that memory dies. For that reason, to increase the monitor lifetime, the smoothly transition feature was deliberately removed.
Have to search the old thread about that topic.
Edit: Brightness changes on Wayland no longer fade smoothly after KDE 6.1 - #4 by digitaltrails
But as I said in that thread, if “Control hardware brightness with DDC/CI” is disabled in the settings and it does not (allow to) transition smoothly I would consider that a bug.
Thank you for the prompt answer. I understand most desktop monitors aren’t designed to have their brightness changed frequently or allow for smooth transitions (a limitation of the longevity of nonvolatile memory like you said), but that doesn’t seem to apply to laptop screens. I can confirm personally that the brightness on my laptop screen does indeed change smoothly.
What about monitors with automatic brightness control? Whether it be an ambient light sensor, the gimmicky fake HDR that cheap gaming monitors have, or the fact that brightness changes step-by-step when physically adjusting the brightness in the monitor’s OSD, there is a strong implication most newer monitors are designed with smooth brightness transitions in mind.
Methinks it’s just a case of features not being sufficiently cataloged, but at this point it would be outside the scope of Plasma and more about Linux drivers.