Abstract: In a camera or other photographic apparatus employing a movable lens, motion imparting means, such as a cam, has respective positions corresponding to infinity, close-up, and intermediate focus positions of the lens. The motion imparting means is rotatable uni-directionally about the optical axis of the lens from one of its corresponding positions successively to the other corresponding positions and back to the first position, for moving the lens bi-directionally along such axis between the infinity and close-up positions. Electromagnetically operated indexing means, such as a pawl and ratchet, is actuatable about the optical axis to rotate the motion imparting means in one direction only. The electromagnetic actuator for the indexing means is movable in opposite directions about the optical axis in accordance with the direction of current flow to the actuator, to actuate the indexing means and to reset itself. The resulting focusing mechanism is a relatively compact, simple unit.

Abstract: A retractable viewfinder for a camera includes a control mechanism which provides compensation or correction for parallax as the objective lens of the camera is focused.

Abstract: A camera shutter having a light-responsive circuit that regulates movement of the shutter to effect an exposure of duration related to actual scene brightness, an exposure-limiting device that operates to limit the duration of the exposure to correspond to a predetermined scene brightness, means for selectively disabling the exposure-limiting device, and shutter reset apparatus that, if the exposure-limiting device is disabled during an exposure, reenables the device when the shutter is reset.

Abstract: A battery checker for checking the condition of batteries under a simulated load includes a timer that automatically disconnects the load from the batteries a predetermined time after the check has commenced.