A retractable lens system includes a linearly movable ring; a
radially-retractable optical element supported by the linearly movable
ring; an exposure control unit supported by the linearly movable ring and
adjacent to the radially-retractable optical element; an exposure control
unit recess formed on the exposure control unit to face the
radially-retractable optical element when the radially-retractable
optical element is in the radially-retracted position; a retracting
device which retracts the radially-retractable optical element to the
radially-retracted position and brings at least a part of a frame of the
radially-retractable optical element to enter the exposure control unit
recess when the linearly movable ring retracts from a ready-to-photograph
position to a retracted position.