To prevent the remarkable change of focus, which is not intended by a user, in the case of applying an imaging system to a camcorder or the like.

By automatically focusing an optical system within a range where setting by an input means is possible in an automatic focusing mode performed by restricting an adjusting range, automatic focusing is performed in a state where the focus is changed only in the range corresponding to the setting of the adjusting range. Thereby, even when a passer-by passes the front of the imaging system and the focus is remarkably changed so as to be focused on the passer-by in the case restriction is not performed at all, the change of the focus is kept in the adjusting range. Thus, the remarkable change of the focus, which is not intended by the user, is prevented.