A camera system comprises a brightness measuring circuit, a exposure line choosing circuit, an operable switch, a film driver and a film driving mode selector. The brightness measuring circuit measures brightness of a photographic scene to send a brightness value. The exposure line choosing circuit chooses one of a plurality of exposure lines in which each lines selects a combination of an aperture value and a shutter speed value at each brightness value. The film driver drives a film in either of a first mode in which the film is wound only one frame in response to the operation of the operable switch and a second mode in which the film is wound frame by frame continuously as long as the operable member is operated. The film driving mode selector selects one of the modes in accordance with the exposure line chosen by the choosing circuit.In the camera system, a photographer may only select the exposure mode in accordance with his intention and purpose in photography, and then the film driving mode corresponding to the intention and purpose is automatically selected.