Coordinated image capturing is appropriately performed even if an error occurs in the synchronization between cameras that are connected via a network. Camera A for image capturing and camera B for providing strobe light are connected via a radio network, and camera A sets a point at which to start exposure for image capturing Tx and a point at which to start strobe emission Tf such that Tx is earlier than Tf, the time difference Id between Tx and Tf becomes larger than a synchronization error Ie between a synchronous clock of camera A and a synchronous clock of camera B, and the sum (Id+If+Ie) of the time difference Id, the strobe emission period If and the synchronization error Ie becomes smaller than exposure period Ix. Then, camera A outputs a strobe emission command with Tf designated and an exposure command with Tx designated, and controls the exposure control mechanism to start exposure at Tx in response to the exposure command. On the other hand, camera B controls the strobe mechanism to start strobe emission at Tf in response to the strobe emission command received via the radio network.