A digital camera system is composed of a camera body and a lens unit removably attached to the camera body. The lens unit has a timing generator (TG) for controlling drive timing of each part of the lens unit. The camera body also has a TG for controlling drive timing of each part of the camera body. When a still image capture mode or a movie capture mode is selected by a mode selection dial, a camera controller switches to a first mode for operating the camera body side TG in synchronization with the lens side TG. When a playback mode is selected, the camera controller switches to a second mode for operating the camera body side TG without synchronizing with the lens side TG.