title: Exposure settings in uvcdynctrl for a Logitech C920?
body: <p>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:</p>
  
  <p>uvcdynctrl -d /dev/video1 -s"Exposure (Absolute)" -- 10</p>
  
  <p>It seems to get as low as 3, and as high as 255, lower values resulting in  darker images (shorter shutter speed / exposure time).</p>
  
  <p>Can anyone tell me the equation how these values are mapped to milliseconds?</p>