A newly designed lens mount for the 645AF provides positive electronic interfacing for the camera's interactive control system, transferring data with total precision to guarantee each system component operates with maximum accuracy, reliability and efficiency.   Camera driven autofocus lenses are both lighter and more economical than lenses with built-in motors. The new mount also accepts all non-autofocus Mamiya 645 lenses for operation in manual stop-down aperture mode and permits focus confirmation.