In the standard contrast detection auto-focus the lens is moved until the contrast in the image is largest. The relative positions of two spots obtained from the focusing of two small diaphragms on ei...In the standard contrast detection auto-focus the lens is moved until the contrast in the image is largest. The relative positions of two spots obtained from the focusing of two small diaphragms on either side of the optical axis is analysed. Depending on the relative positions of the spots, the lens is moved towards or away from the sensor. An infrared laser pulse is emitted and the distance of the object of interest is determined from the return time of the reflected pulse.
