A zoom dial mechanism includes a zoom dial mounted on a base plate so as to extend through a central hole of the base plate and so as to be turnable, a coil spring mounted on the base plate to urge the zoom dial toward a neutral position, and a push knob mounted in a central hole of the dial. The base plate has a groove concentric with the central hole. The coil spring is mounted in the groove. The mechanism further includes a first rib fixed to the dial so as to abut one end of the coil spring and a second rib fixed to the dial so as to abut the other end of the spring. The spring is compressed by the first rib when the dial is turned clockwise, and the coil spring is compressed by the second rib when the dial is turned counterclockwise.