====== Disable/Enable Autofocus ======


List all devices
<code bash>
v4l2-ctl --list-devices
</code>

Example:
<code bash>
Microsoft© LifeCam Studio(TM): (usb-0000:00:14.0-2.1):
      /dev/video3
      /dev/video4
</code>
Here ''**/dev/video3**'' is the webcam. To get all options:
<code bash>
v4l2-ctl -d /dev/video3 --list-ctrls
</code>
If the focus can be configured can be seen:
<code bash>
focus_abolute ... (int): min=0 max=40 step=1 dfeault=0 value=4 flags=inactive
focus_auto ... (bool)  : default=1 value=1
</code>
To deactivate autofocus and set it manually:
<code bash>
v4l2-ctl -d /dev/video3 --set-ctrl=focus_auto=0
v4l2-ctl -d /dev/video3 --set-ctrl=focus_absolute=12
</code>