A camera system is capable of exactly catching the subject at the time of release operation by the imaging device of the camera head in accordance with the release button operation at the side of the camera main frame, even if the camera head and the camera main frame are not formed in a unitary body. There are provided two dedicated lines for supplying to a head CPU a release signal according to the half-depression and a release signal according to the full-depression, respectively. Other signals are transmitted via serial interfaces to be driven by three-wire serial drivers. Only the release signals are transmitted from the camera main frame via the two dedicated lines to the camera head.