Adjust the Display With xgamma and xrandr

Sadly, this page is just copied from the Linux How Do I: A Linux Q&A page for now. Details on these commands will be added in the future.

[DISPLAY RESOLUTIONS AVAILABLE FOR MONITOR OR SET FROM COMMAND LINE]

Use the xrandr command. Xrandr is used to set the size, orientation and/or reflection of the outputs for a screen. It can also set the screen size.

If you type 'xrandr' and ENTER you will see info about your current display. See if you are using something like VGA-1, DVI-0, HDMI-1, DP-1, etc etc <- examples only

DO NOT TYPE: xgamma --output VGA-1 --brightness 0 (substitute VGA-1) for your display, this will make your screen black and you will see nothing. Here is a working example:

xrandr --output VGA-1 --brightness 0.75

Learn more

man xrandr

[ADJUST DISPLAY CONTRAST AND TINT FROM COMMAND LINE]

You can Adjust the Display With xgamma and xrandr from the command line. See xrandr above.

xrandr --output VGA-1 --gamma 1:1:1

Use the xgamma command. A gamma value of 1.0 is the default. A gamma value of 0.8 would give you more contrast. A value of 1.4 would be much less contrast. Example usage:

xgamma -gamma 0.8

xgamma - Alter a monitor's gamma correction through the X server. The gamma correction can either be defined as a single value, or separately for the red, green and blue components. Also: -rgamma -ggamma -bgamma

Learn more

man xgamma

testing

$ xgamma
-> Red  0.700, Green  0.700, Blue  0.700
$ xrandr --output VGA-1 --gamma 1.5:1.5:1.5
$ xgamma
-> Red  0.700, Green  0.700, Blue  0.700
$ xrandr --output VGA-1 --brightness 0.5
$ xgamma
-> Red  0.700, Green  0.700, Blue  0.700
$ xgamma -gamma .9
-> Red  0.700, Green  0.700, Blue  0.700
<- Red  0.900, Green  0.900, Blue  0.900

eye strain relief

The full brightness setting is:

xrandr --output VGA-1 --gamma 1:1:1 --brightness 1.0

The nighttime setting is:

xrandr --output VGA-1 --gamma 1.1:0.8:0.7 --brightness 0.55