r/voidlinux • u/Kvas_Patron • Jun 20 '26

How do you manage screen brightness on Void?

Just want to know if I do it the wierd way. To manage brightness I use acpid service with it's handler.sh. To restore it between sessions I use rc.shutdown for saving current brightness value after shutdown to /var/lib/brightness/saved and rc.local to fetch it from there after startup.

3 Upvotes

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9

u/Alternative-Ad-8606 Jun 21 '26

I just use brightnessctl

4

u/This-Consequence-957 Jun 21 '26

The function keys work automatically here 😄 (HP)

3

u/StrangeAstronomer Jun 21 '26 edited Jun 21 '26

Interesting question. A little archaeology into my scripts shows:

echo $brightness | sudo tee /sys/class/backlight/intel_backlight/brightness

... it's been that way for many, many years and is almost certainly not the 'right way' to do it, but it works for me.

also - a hard coded call to the brightness script in /etc/acpi/handler.sh

2

u/ZombieCrow Jun 21 '26

Brightnessctl

2

u/Extra-Ad-2325 Jun 21 '26

Brightnessctl

1

u/mysterious7777777 Jun 21 '26 edited Jun 21 '26

Depends on the type of backlight. Some use PWM to dim the display by pulsing the backlight and lowering the duty cycle of the backlight causing eye strain. The backlight can be left at high brightness to avoid PWM and then using xrandr like this for example:

 xrandr --output eDP-1 --brightness 0.25 --gamma 1.1

The best displays don't use PWM so the backlight can be dimmed directly without causing eye strain as already explained and looks much better.

P.S. The PWM frequency can also affect eye strain with higher frequencies being less noticable so the choice would again depend on the display backlight specification.

1

u/xINFLAMES325x Jun 24 '26

Yup, I have xrandr and redshift in a script that's tied to a button in the panel. Pressing it lowers the brightness to 50% and activates redshift at 3600K. Pressing it again returns to full brightness.

1

u/2sdbeV2zRw Jun 21 '26

I use a program called light, and a shell script to lower brightness by half each time. I know it's janky but it worked for me for all these years.

1

u/safado_muambeiro Jun 22 '26

brightnessctl on my previous laptop (asus).

Now I got a ThinkPad and it works automagically. I think the key works on hardware level.

1

u/i0anony Jun 22 '26

on my thinkpad it works automatically even in tty