Autofocus

Autofocus is a function in which the lens or camera automatically sets image sharpness according to the distance of the subject. Focusing is performed by a small motor that moves the lens elements based on an evaluation of the image or a signal from the sensor. The operator can therefore concentrate on movement and composition, which matters with action cameras. Its advantages are quick reaction to changes in distance and easy use while moving. In poor light or in low-contrast scenes, focusing may hunt or lock onto the wrong subject. Autofocus is best suited to dynamic scenes and everyday filming.