An optical apparatus detects the moving velocity of a main object on an
imaging plane and computes the moving velocity of the main object on the
basis of the difference between the detected moving velocity on the
imaging plane and the velocity of a panning shot captured by a user.
During exposure, the optical apparatus detects the difference between the
computed moving velocity of the main object and the panning-shot
velocity, that is, an error of the panning-shot velocity, and decenters
the optical axis of an imaging lens so as to correct the error, thereby
enabling the user to capture a satisfactory panning shot.