(under subclass 505) Subject matter comprising means for manual adjustment of a diaphragm aperture setting means so that the aperture remains fully open until a setting means is released or the diaphragm aperture is set or a device is pressed to fully open the aperture and returns to set position after release of a pressed device.
SEE OR SEARCH THIS CLASS, SUBCLASS:
461, for a shutter with diaphragm that opens for focusing or viewing.
