Screen brightness 100% with proprietary Nvidia driver

Question

After having installed the proprietary Nvidia driver on Debian Jessie in order to play Steam games (which I now can), I can't change the brightness at all, it is stuck at the maximum and is irritating my eyes at night. I have already tried all of the solutions in the Debian wiki

such as adding the line: Option "RegistryDwords" "EnableBrightnessControl=1;" to /etc/X11/xorg.conf and /etc/X11/xorg.conf.d/20-nvidia.conf

but that has not worked, even though in the Debian forums it seems to work (marked solved):

xbacklight does not work at all, and I don't know what to do anymore. I will post any outputs for whatever terminal commands, please help.

Solution 1

After adding the following line in your X device configuration

Option  "RegistryDwords"  "EnableBrightnessControl=1"

You can use the software xbacklight to adjust the brightness:

xbacklight -set 60

Solution 2

Complementing @semente answer:

xbacklight +10
xbacklight -10

increase and decrease the backlight in steps of 10%. They can be associated to keys with xbindkeys by following the instructions here. Below is sample of the .xbindkeysrc with this commands associated to the Windows + F5 and Windows + F6 keys:

"xbacklight +10"
 Mod4 + F6

"xbacklight -10"
 Mod4 + F5

Solution 3

I followed this tutorial to install NVidia driver for linux from NVidia:

http://allaboutlinux.eu/remove-nouveau-and-install-nvidia-driver-in-debian-8/2/

and now I have NVIDIA X Server Settings GUI which can be launched from applications drawer, then I go to GPU 0 --> CRT-0 --> Color Correction and I'm able to set brightness to negative value.

Comments

[Tim Richardson]

This doesn't change the backlight brightness.

[LatinSuD]

Added that option to my /usr/share/X11/xorg.conf.d/20-nvidia.conf in Debian 8 and now everything works normally in KDE

[rogerdpack]

Seems KDE is more forgiving than gnome, FWIW askubuntu.com/a/1152763/20972

[haidarvm]

thanks for this color correction settings, i didn't know that @TimRichardson, you could use xrandr --output HDMI-0 --brightness 0.7 change the HDMI-0 with your monitor