An undesired signal contained in a signal related to blur suppression, e.g., an error output signal contained in a blur detection signal and obtained upon generation of a shock, is stored. When the state represented by the signal is determined without using the signal, and an undesired state is determined, e.g., when a state in which an error output signal is contained in a blur detection signal is predetermined from the state of a structure for generating a shock or impact, the signal related to blur suppression is accordingly synthesized with the stored undesired signal, e.g., the error output signal is subtracted from the blur detection signal, thereby forming a corrected signal for blur suppression, to perform a blur suppression operation in accordance with the corrected signal.