How to change brighness on Lubuntu desktop?

Question

I'd like to reduce the screen brightness on my Lubuntu desktop (Ubuntu 16.04).

I googled but could not find any soluton that works. (like using xbacklight -set 45 command.

Appreciate a simple working solution.

Answer 1

execute any of these inside root terminal

echo 1 > /sys/class/backlight/acpi_video0/brightness sudo echo 1 | sudo tee /sys/class/backlight/acpi_video0/brightness

if /sys/class/backlight/ folder is empty

nano /boot/grub/grub.cfg add this to kernel line

acpi_osi=Linux acpi_backlight=vendor

or

nano /etc/default/grub

see a line like GRUB_CMDLINE_LINUX_DEFAULT and add

acpi_osi=Linux acpi_backlight=vendor

save and run

update-grub

to save changes to grub

reboot

......

Answer 2

I use Lubuntu with an Nvidia graphics card. The brightness setting is in the "NVIDIA X Server Settings" app. It's kind of buried though - you have to select the "HDMI-0" from the menu on the left, and then click the "color correction" tab.

You don't mention your graphics hardware, but if you don't use Nvidida, perhaps the setting is related to your graphics card as well.