Sudden jumps to 96% every 15-20 seconds

[DunhamGitHub]

Last night (observed before) when watching a movie (Safari, Netflix), having 160% brightness, the screen suddenly dims and when I click the status bar icon it shows 96%.
I have to manually drag it back to 160% and it jumped back to 96% after 15-20 seconds.
After 3 times I gave up, quit the app and opened "Vivid" = no such issues.

Please advise...

MacbookPro 14", Ventura 13.1

[waydabber]

Hi there, it might be that the ambient light sensor is enabled and it deems the environment dark so it adjusts the brightness accordingly. You might have to turn off "Auto Brightness" in the app menu or under System Settings/Displays (as I see you have this menu item hidden).

Please note if you are watching HDR content, it is best not to use XDR brightness upscaling during that time but instead set the display brightness to around 75% in order to avoid HDR clipping (that will take effect when the slider is set beyond 100%) and have as much uncompressed HDR (EDR) headroom as possible to enjoy the dynamic range the movie maker intended to have (I am not sure if that particular movie is HDR or not, so I am just saying in general).

[waydabber]

Note: Rregarding Vivid - honestly I did not try the app in depth but it might be that it has a generally simpler implementation - BetterDisplay takes into account system induced brightness changes - including touchbar, control center and ambient light sensor induced ones - and assumes when such a change occurs, there is a reason for that and the newly set brightness level should be honored (even though these are obviously limited to a maximum of 100% brightness). It might be that Vivid just keeps the upscaling level fixed while there is a slight overall brightness decrease induced by the ambient light sensor, creating a mixed output.

I think it's simplest to turn off auto brightness in general if an user is keen on taking control of brightness, but now that this issue come up, It would probably be a good idea to disable the ambient light sensor automatically when upscale is taking place.

#1339

I might also add an other XDR upscaling mode that scales upscaling according to the hardware brightness level, fully interweaving the two (this means the ambient light sensor and control center will be able to control the overall upscaled brightness range). This will not be good for HDR movie watching (as there won't be a clear line below which HDR clipping does not occure), but on the other hand will make XDR upscaling accessible via keyboard even when accessiblity permissions are not given to the app.

#1340

[DunhamGitHub]

Thank you for the update.

Now where can I find "auto brightness" hmmmm...?

[waydabber]

Sorry for not clarifying this - it is normally found in the app menu:

However you seem to have these options disabled. I know it might add a bit to clutter, but probably it's best to change relevant menu items from Hidden to Show when expanded - this way you'll still maintain a less cluttered appearance but can reach extra settings quickly whenever there's a need for them. Allowing this section will let you see the Auto Brightness setting:

[DunhamGitHub]

Thanks 👩🏼‍🎓

(I can confirm this was ON in my settings, turned it off now, will probably test it out but consider this solved)