HD Pro Webcam C920 ubuntu 20.04

# How to adjust brightness for HD Pro Webcam C920  on ubuntu 20.04
# 
# Install the v4l2-ctl
apt-get install v4l2-ctl

# list the decives
v4l2-ctl --list-devices

###
HD Pro Webcam C920 (usb-0000:00:14.0-1.2):
	/dev/video2
	/dev/video3

###

# list the possible controls
v4l2-ctl -d /dev/video2 --list-ctrls

# set the control
v4l2-ctl -d /dev/video2 --set-ctrl=exposure_absolute=600

# To visualize use the result use the Chess program open during the control changing

The command changed in the last ubuntu update, now it is

#! /bin/bash
v4l2-ctl -d /dev/video2 --set-ctrl=auto_exposure=1
v4l2-ctl -d /dev/video2 --set-ctrl=exposure_time_absolute=$1

To list all the available commands in your decive use:

v4l2-ctl -d /dev/video2 -l