Toronto. One of the perks of collecting Leicas is the vast array of accessories available – not just additional lenses, but close-up frames, lens elements, extension tubes, view finders, rangefinders, timers, rings, hoods, bellows, flash guns … and a slow speed device.
Screw-mount Leicas use a tiny focal plane shutter with two horizontal curtains. The gap between them gives an exposure from about 1/20th second to 1/300 or 1/500th second. A “B” setting sends the first curtain across the focal plane when the shutter button is first pressed and the second curtain when the shutter button is released.
At first, customers asking for a slower timed shutter were sold a special model B camera with a leaf shutter in lieu of the focal plane shutter. Later camera models added a timer to the camera so users could set the shutter to slower times up to a one second exposure. Early and less expensive models did not have this slow speed timer built in.
Owners of a less costly Leica could return it to the factory to have a slow speed shutter time installed or from about 1935 they could buy an accessory code named HEBOO to attach to the the shutter release to provide slower shutter speeds (1/8, 1/4, 1/2, 1 sec).