An auto-focus apparatus including an evaluation value calculator
periodically calculating evaluation values using high frequency
components of image signals in a specific region of a subject image, a
distance measurement unit measuring a distance to a subject and output a
distance measurement result, a control unit outputting instruction values
based on the evaluation values and determining whether a subject image is
in-focus or out-of-focus, and a storage storing the distance measurement
results and lens positions. In the apparatus, after searching the peak of
the evaluation values, the control unit returns the lens to the position
at which the relative maximum has been detected, obtains evaluation
values, stores lens positions and distance measurement results when the
evaluation values satisfy a prescribed condition, and retrieves distance
measurement results and lens positions when the number of times that
results are stored reaches a prescribed number, and computes a correction
amount.