I managed to set the exposure value, as well as any other controllable value of the Logitech C920 webcam, manually and fixed. (I am doing computer vision research with it). However, I can not find any source that tells me in which unit the exposure value is in:
uvcdynctrl -d /dev/video1 -s"Exposure (Absolute)" -- 10
It seems to get as low as 3, and as high as 255, lower values resulting in darker images (shorter shutter speed / exposure time).
Can anyone tell me the equation how these values are mapped to milliseconds?
