Patent ID: 8121469

Claim:
An autofocus system comprising: an image pickup unit that takes a subject image formed by an optical system; an autofocus unit that performs focus adjustment on the optical system so as to bring into focus a subject within a predetermined AF area in a photographing image taken by the image pickup unit; a tracking unit that moves an AF frame, which indicates an outline of the AF area, in accordance with the movement of the subject within the photographing image taken by the image pickup unit; a face direction detection unit that detects a face direction of the subject from the photographing image; a face direction registration unit that registers the face direction of the subject together with coordinates which represent a position of the AF frame in the photographing image; and a face direction comparing unit that compares the detected face direction of the subject with the registered face direction, wherein tracking of the subject is performed by comparing the face direction, which is detected from the subject within the photographing image, with the registered face direction.