97. Adjusting webcam sensitivity/brightness on linux

The past year I've had problems with web cams on debian -- some of them look fine, some are way too dark, but either way, I had no good method of adjusting any of the settings. Cheese could be used for some settings, but it's not enough.

Yesterday I was greeted with this image:

While I could probably let in a bit more light in my office, it's still on the dark side...

There are command line tools for adjusting v4l devices (e.g. v4l-conf), but in this particular case a GUI tool would come in handy -- v4l2ucp. It can be installed from the standard debian repos.

Auto Gain can't be turned off for the zc3xx driver. Turns out that the "Light frequency filter" was set to no flicker by default. Changing it to 50 or 60 Hz lead to the image below:

The number of settings you can change depends on your driver --  below is the v4l2ucp window for an integrated thinkpad webcam: