A camera system having a camera body and a photographing lens, which can be mounted to and dismounted from the camera body, includes a determining device which determines a type of the photographing lens in accordance with data received from the photographing lens; and a body controller which has a function to send body data and individual function data to the photographing lens, wherein each of the individual function data is required for a corresponding function that the photographing lens possesses. The body controller sends all the body data to the photographing lens regardless of the type of the photographing lens, and sends a portion of the individual function data which is associated with the type of the photographing lens to the photographing lens.