Dim screen past the minimum on Ubuntu

My laptop's screen is far too bright at night, even if I set it to minimum brightness. I know that it is capable of being dimmer, because Windows will dim it further if I leave it idle. However, I can't figure out how to dim it lower to minimum on Ubuntu. Is there a way?

I've looked at this question, but it's talking about Windows.

cpast

Posted 2013-03-04T05:03:36.873

Reputation: 2 279

This solution works best for me – Pavel – 2017-03-27T22:57:43.727

If the back-light is set to the minimum, then that is all you can do with it. Try adjusting the brightness, contrast, and gamma of the video-card with something like xgamma or other program.

– Synetech – 2014-01-03T05:09:45.983

Answers

Here is a link specifically addressing setting screen brightness below the minimum:

Decrease Backlight Below Minimum – Ask Ubuntu

Open Terminal
Enter the following command:
cat /sys/class/backlight/intel_backlight/brightness
Write down the resulting value (12421 in my case)

Divide value by 6 and write it down (2070 in my case)
Enter the following in the terminal, replacing 2070 with your value:
sudo su -c "echo 2070 >/sys/class/backlight/intel_backlight/brightness"
Close Terminal

For future usage of the last command, open Terminal, press Ctrl and R together, start typing brightness. When the last command appears, just press Enter.
It works for me on a Samsung NC110 with Ubuntu 12.04.

Austin ''Danger'' Powers

Posted 2013-03-04T05:03:36.873

Reputation: 5 992

For me, this dimmed the screen well past the minimum. :) (Lenovo Y50) – Chris Cooper – 2014-12-19T04:31:39.300

Also worked great with 14.04 on acer E15. +1 – davewoodhall – 2015-03-06T05:01:21.727

I get cat: /sys/class/backlight/intel_backlight/brightness: No such file or directory from the first command. Is it because I have a discrete video card (GTX460M) in my laptop? (I'm on Ubuntu 14.04 LTS) – Borgleader – 2015-07-08T01:13:08.397

@Borgleader Yeah, just look in /sys/class/backlight for the folder corresponding to your video card. – Azmisov – 2015-09-19T07:21:43.943

Any solution for desktop? – Dewsworld – 2016-05-10T16:17:48.027

1That gives better control within the standard range. I want to go outside the standard range. – cpast – 2013-03-04T06:05:46.810

you can also use "xgamma -gamma 0.5" command to decrease the intensity of RGB colors. See xgamma usage by using command "man xgamma". For my intel display the gamma brightness varies from 0 to 10(including decimal values).

Saurav Kumar

Posted 2013-03-04T05:03:36.873

Reputation: 41

1This does not dim white color – Serge – 2019-10-16T07:12:29.950