Windows 10 desktop screen brightness shenanigans

November 1, 2020 10:46 PM

My Windows 10 desktop at work has suddenly acquired some kind of automatic brightness adjustment. As an example, if I adjust the Ask web page with its green background to cover the whole screen, the brightness adjusts down a little. If I tab over to a Google search that has a white background, the brightness adjusts up again.

And if I scroll down a long page with white background and some images, the brightness will go up and down as the amount of white on-screen changes. Google will only show me fixes for people who have trouble with their laptops' adaptive brightness. But my desktop does not have the brightness sensor or show the associated option. Any ideas?

posted by Harald74 to Computers & Internet (9 answers total)

This could be a feature of the monitor you are using - if you can find the monitor controls (sometimes they are hidden underneath or on the side) and look in the menu. If you can find the factory reset option that should put it back to sane defaults, or if it has a set of preset modes then the "Game" or "Movie" mode should do the least amount of messing with the image.

Alternatively it could be something going wrong with the backlight circuit in the monitor, although I usually see it making things dimmer when displaying a mostly white screen.
posted by samj at 1:07 AM on November 2, 2020

Sounds like some kind of HDR/Dynamic Range setting your monitor has gone awry.
posted by Sunburnt at 1:19 AM on November 2, 2020

I've got two identical HP monitors hooked up and they behave exactly the same. I tried resetting them per your suggestion, but the behaviour is still there.

My monitors show up in the Windows settings as not actually having any HDR capabilites, so there's nothing to adjust there.
posted by Harald74 at 2:24 AM on November 2, 2020

That only really leaves the graphics card and drivers - if you have an nvidia card and nvidia control panel, you could check under Display menu -> Adjust desktop color and settings and see if there's anything set in there.
posted by samj at 2:53 AM on November 2, 2020

I fiddled around a bit more, and it seems like I have a similar problem to other HP Z27n monitor owners. There's a feature called "Dynamic Contrast" and it seems to like to activate on its own. A thread with some complaints can be found here. In my case neither factory reset or turning power savings mode off seemed to do the trick, but some of the presets like "Photo" turned Dynamic Contrast off, so that's what I went with for now. Thanks for yours suggestions, though!
posted by Harald74 at 3:25 AM on November 2, 2020

(The option is also found under Main Menu -> Image Control)
posted by Harald74 at 3:27 AM on November 2, 2020

There’s also a “night light” option in win10 that adjust your display colour temperature automatically that you might want to make sure is turned off.
posted by mhoye at 4:55 AM on November 2, 2020

Did you or someone install something like a "dark mode" add-on? I was having problems like yours and it was driving me nuts: some sites blinded me and others you couldn't read. I don't remember how I found it or who told me to look for it, but I got rid of it and things are just fine. I'm thinking it was installed on a FF update.
posted by james33 at 5:24 AM on November 2, 2020

No, it was all in the monitor. It reverted again since yesterday, and I turned it off again through the built-in menu system in the monitor.
posted by Harald74 at 5:00 AM on November 3, 2020