On linux you can use v4l2-ctl to fine tune the webcam settings (focus, gain, white balance, etc). The C920 has really poor firmware, none of the auto settings

On linux you can use v4l2-ctl to fine tune the webcam settings (focus, gain, white balance, etc). The C920 has really poor firmware, none of the auto settings work well. Auto focus is particularly bad. I wrote a quick script which hard locks all of the settings of my C920 to the optimal values for my office conditions. The low light performance of the C920 hardware is quite bad, but if you have adequate lighting and manually configure the setting you can get a pretty good setup.