To decrease communication amount in the case of focus detecting operation and to control other functions without any trouble, in a camera which has a focus detecting function by a contrast detecting system (wobbling method) on a camera side and has a lens driving control means on a lens side, and which is connected to the lens so as to communicate therewith.

After information (driving cycle and driving amount) concerning the driving of a focusing lens is transmitted from the camera to a photographic lens device, the effect that the driving of the focusing lens based on the information concerning the driving is started/stopped is transmitted from the camera to the photographic lens device.

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