...and a feature known by few.
By Heinz Richter
Being the first viable 35mm camera ever, the Leica has been copied more than any other camera. Thus the Leica is also responsible for putting some of its competition on the market. The Leica is the cornerstone of 35mm photography and there should be no doubt that photography as we know it today would be much different without Oskar Barnack, Max Berek, Ernst Leitz II and the original prototype, the Ur-Leica from 1913.
As soon as the Leica had proven that 35mm photography was to be taken seriously, other companies followed with their own cameras in this new field of photography. The second 35mm camera to reach the market was the Zeiss Contax, soon followed by the Kodak Retina, made by the old Nagel company in Germany. It wasn't until later that Nikon and Canon joined the ever growing field of 35mm photography.
Both Nikon and Canon got their start by copying lenses and cameras made by Leitz and Zeiss. The early Canon cameras were quite obviously based on Leica cameras. Nikon, on the other hand, chose to copy the Zeiss Contax. But there was more to the camera than what met the eye. The camera body was clearly a copy of the Zeiss Contax, including the rangefinder and the lens mount. But the shutter was definitely not a Zeiss design. Upon closer inspection it was obvious that it was taken entirely from the Leica. That decision apparently had been made because it was of a much less complicated design (thanks Oskar Barnack) and thus much more reliable than the vertically traveling, roller desk top type shutter of the Contax. The Leica shutter was copied in virtually all details resulting in the Nikon being one of the very few cameras that utiluzed a collar type cable release.
Several years later, when it became apparent that rangefinder cameras would be replaced by single lens reflex (SLR) cameras, Nikon simply converted the Nikon rangefinder camera to an SLR by eliminating the rangefinder from the camera and adding a mirror housing. Thus the original Nikon F was born. It too featured the Leica shutter, virtually unchanged. The Nikon F soon became one of the most successful, professional SLRs on the market and Leica technology was a definite part of that.
Using the Leica shutter offered another, little known feature, mostly unknown to even Leica users. The Leica shutter used by Nikon was that of the Leica screw mount cameras and it made those Leicas, the Nikon rangefinder and Nikon F SLRs the only cameras to ever incorporate that feature.
It was the ability to allow double exposure with perfect registration, but not just simple double exposures on the last frame but with any frame that had been exposed on the roll of film.
Users of these cameras might have noticed that the shutter release button turns when rewinding the film. To make a double exposure on the last exposed frame all that is necessary is to activate the rewind release and winding the film back for one full revolution of the shutter release button and then go beyond that for not quite another half revolution. After that the camera has to be switched back to the film advance mode and the film transport knob or advance lever moved to cock the shutter. This will also advance the film which will automatically stop with perfect registration on the last exposed frame. At this point the second exposure can be taken on that frame. Repeating the above steps will allow unlimited exposures on the same frame.
Please notice the identical position of the shutter speed dial, the shutter release and the film advance. This is due to both cameras using virtually identical shutters.
To take additional exposures on any previous frame one needs to do the same procedure as above. Except rather than winding the film back just one revolution of the shutter release knob, one needs to make it do as many revolutions as the number of frames the one is back that is to receive the additional exposure. Don’t forget to go about one half revolution beyond, activate the advance until it stops and take the exposure.
To go back to taking a new picture, block any light from entering the lens and take as many ‘blind’ exposures as the number of frames you wound back.
This might require some practice. To do that with any accuracy, take an old, unexposed or undeveloped roll of film and load it into the camera. With the camera set on ‘B’ and with the lens removed, take several frames and mark the outline with a pen and number the frames consecutively. This will allow you to practice the above procedure with any number of frames.
It would be quite interesting for me to know how many readers knew about this.