Auto Focus

Selects the best focus positions depending on the subject distance. This system uses an infra-red transmitter and an infra-red receiver linked via an electronic logic circuit to a motor which moves the lens back and forth in minute steps. When the shutter button is pressed an infra-red pulse is sent from the camera. The receiving cell measures the strength of the returned pulse and the logic circuit translates this strength into a "camera to subject" distance. This information is then used to activate the electric motor that positions the lens to produce the sharpest image.