(m,k)-firm constraints and DBP: counter-intuitive phenomena and exact feasibility test

Diaphragm setting device for a photographic camera lens shutter, which comprises an elongate carrier mounted on the outer periphery of the shutter housing and a movable slider operatively connected to the diaphragm adjusting ring of the lens shutter, such that the slider is displaceably supported and guided on the carrier and has a scale corresponding to diaphragm settings, whereby, e.g. manual, displacement of the slider causes the diaphragm adjusting ring to adopt the setting indicated on the slider scale. The carrier and slider of the diaphragm setting device may be attached to the shutter housing, advantageously either by means of screw fastenings or by means of a quick attachment and release plug arrangement, i.e. at an exterior location on the front rather than on the rear of the shutter housing.