Brightness Key Lowest Setting

[dvdmuckle]

@ColtonDRG and I were discussing on IRC late last night / early this morning about better screen brightness manipulation via the brightness media keys. Having the brightness keys able to entirely turn off the back light was seen as not as useful as having it go as low as possible compared to the brightness slider.

Another separate idea was being able to mirror the brightness "ramping" that ChromeOS did, which was very useful for lower settings. Not as important as adjusting the lowest setting on the brightness media keys, though.

[lyam23]

I found the brightness control in ChromeOS to be superior than the current experience. Agreed on lowest setting as well.

[reynhout]

I like that repeated brightness-down keypresses will turn the backlight off. It's a feature I use on OSX laptops, but I don't know if it's common elsewhere.

I agree that 10 equal-sized steps makes the lowest setting way too bright though.

I just patched xfce4-power-manager with an attempt at solving the problem. I added a "minimum ON" step at 1% of the max illumination. If you're stepping down, it adds an extra step there before turning off. Stepping up, it goes straight to 10%. It's in the testing repo now, so give it a spin and let me know how you feel about the approach.

[lyam23]

Side question: If I add the testing repo, dist-upgrade any packages, then remove the testing repo and dist-upgrade again, will it revert testing pkgs to production pkgs?

[reynhout]

@lyam23 yes. If you disable the repodist that supplies that version of the package, dist-upgrade will replace the package with the newest-known version that is available. It will give you a warning if that will be a version downgrade.

If you don't want to add the testing repodist, you can do this:

rm -f xfce4-power-manager*.deb
curl -O https://apt.galliumos.org/pool/main/x/xfce4-power-manager/xfce4-power-manager_1.4.3-0ubuntu1-galliumos13+dev1_amd64.deb
curl -O https://apt.galliumos.org/pool/main/x/xfce4-power-manager/xfce4-power-manager-data_1.4.3-0ubuntu1-galliumos13+dev1_all.deb
curl -O https://apt.galliumos.org/pool/main/x/xfce4-power-manager/xfce4-power-manager-plugins_1.4.3-0ubuntu1-galliumos13+dev1_amd64.deb

sudo dpkg -i xfce4-power-manager*.deb

The pkgs will still be replaced when you dist-upgrade again.

[adrinux]

I like to be able to turn off the screen when I'm only listening to music, I'd hate to see that go entirely. Testing works fine though.

[lyam23]

@adrinux That's a good use case. I'd support leaving the option to fully blank the screen while incorporating a logarithmic step at lower levels.

@reynhout Thanks

[reynhout]

@lyam23 I initially thought a curve would be useful but I don't think it helps. There really aren't any desirable steps between 10% and 1% for me, but maybe others disagree.

Test with echo X > /sys/class/backlight/intel_backlight/brightness, where X is in the range 0-937 (on my C720). 1% is therefore obviously 9, and 2% is 18 (C int division!), etc. The standard steps are in 10% increments.

[adrinux]

I'd like to remind everyone that your perception of screen brightness is related to the surrounding environment. So if you do test do so in both bright daylight and a dark room (give your eyes time to adjust). Those lower ranges are presumably only useful in dark rooms though?

[reynhout]

@adrinux Right. The only purpose I see for a step below 10% is for use in (very) dark rooms when 10% is too bright.

[adrinux]

I have no complaints about how it worked before, but also find current testing fine as well. I'd agree with @reynhout though, not sure any more steps at lower levels would be useful. Mostly anything below 9 equated to 'almost too dim to read'. FWIW I'm not a fan of super bright screens, mostly seem to stick at 195 (20%?) on this Falco.

[reynhout]

I raised the minimum "on" step to 2% (from 1%) to improve readability of black text on white backgrounds. This also makes it easier to notice when the backlight isn't quite all the way off, while stepping downwards in a bright room, while still being dim enough for use in a very dark room.

Package 1.4.3-0ubuntu1-galliumos14 is pushed to stable and available via the usual mechanisms. Closing ticket; please re-open if issues arise.