An autofocus apparatus includes an imaging device that captures a subject
image through a photographic lens; an AF area determining device that
determines a range of image signals to be used for autofocus adjustment
based upon image signals provided by the imaging device; a focus
adjustment device that adjusts a focal point position achieved through
the photographic lens by driving a focus lens so as to maximize contrast
achieved with the image signals in the determined range; and a control
device that controls the focus adjustment device, if the range of the
image signals determined by the AF area determining device has been
altered, so as to adjust the focal point position by using image signals
in the altered range.