Focus Control

org.firstinspires.ftc.robotcore.external.hardware.camera.controls.FocusControl

At a distance called “focus length”, a subject’s image (light rays) converge from the lens to form a clear image on the webcam sensor.

If supported by the webcam, focus can be managed with these FocusControl methods:

• setFocusLength(double focusLength)

• getFocusLength()

Distance units are not specified here; they may be undimensioned values within an allowed range. For example, the Logitech C920 allows values from 0 to 250, with higher values focusing on closer objects.

The webcam may support minimum and maximum allowed values of focus length. These can be retrieved with:

• getMinFocusLength()

• getMaxFocusLength()

There are no set() methods for min and max focus length; these are hard-coded in the webcam’s firmware. Note that firmware settings may vary among different versions of the same webcam model.

These and other focus methods are called on a FocusControl object, as described above for exposure.