September 19, 2015

How to adjust screen brightness in linux

This tip came from the current issue #59 of Full Circle Magazine. There are no brightness controls in Gnome GTK3.x  I'm running Ubuntu 11.10 under the Gnome Classic desktop. It fixed an aging CRT monitor I have and use in one of my rigs. Many thanks ! Enjoy.

Q: When I try to reduce the brightness on my laptop using System Settings, it doesn't change.

A: Open a Terminal, and enter this command:

xgamma ­-gamma .5

You can try different values than .5, to see what works for you. ( .8 works great for my monitor. )

The other available values are:

usage:  xgamma [-options]

where the available options are:
    -display host:dpy       or -d
    -quiet                         or -q
    -screen                      or -s
    -gamma f.f                Gamma Value
    -rgamma f.f               Red Gamma Value
    -ggamma f.f              Green Gamma Value
    -bgamma f.f              Blue Gamma Value

If no gamma is specified, returns the current setting