LEICA is a brand name synonymous with 35mm photography and rangefinder cameras. LEICA introduced many features which were then adapted by other 35mm cameras:
- The LEICA was the first miniature camera to use the inexpensive standard cinema film with the LEICA negative size 24 X 36 mm.
- The LEICA was the first regularly made camera to possess automatic coupling between film winder and shutter setting mechanism. The LEICA owner did not experience double exposures, except by his special intention.
- The LEICA was the first camera to possess automatic focusing by coupling the interchangeable LEICA lenses with the built-in range finder.
- The LEICA was the first miniature camera to possess interchangeable lenses: wide angle and telephoto, ultra fast and soft focus lenses were at the disposal of LEICA photographers.
- The LEICA was the first to possess a speed range from 1/1000 to 1 full second.
- The design of the LEICA has remained faithful to its basic principle; it was from the beginning designed so that later additions and improvements could be easily embodied.
Many people rely upon first impression. This is not always conclusive, of course, but even under such a test the LEICA never fails to show its superiority. Its very appearance is that of a thoroughbred - beautifully streamlined body of smooth, satiny chrome or black lacquer, faced with a special rubberoid composition which withstands all wear and the elements indefinitely, and looks like leather. All-metal construction assures freedom from warping and breaking - a special alloy sees to it that the LEICA is as rugged as it is practical, yet as precision-made as the finest watch. The knurled control knobs are conveniently situated for easy and speedy operation. Rounded corners make the camera fit snuggly into the hands when in use. The noble-looking lens mounted in a smart-looking chromium finished lens mount, completes the picture.
The Series III were the most advanced models equipped with a built-in range finder and view finder. These bodies allowed the use of slow shutter speeds down to 1 second and a top shutter speed of 1/1000 second (except for the Model F released in 1933). The Series II did not have slow shutter speeds, and their top shutter speed was 1/500 second. The Series I differed from the Series II in the absence of a built-in range finder and view finder. Ig, though, was the only Series I body that had slow shutter speeds and a top shutter speed of 1/1000 second like IIIg. Finally, there was also Leica 250 (aka Reporter), which appeared in 1933. It was a Leica II, III, or later IIIa, capable of up to 250 exposures thanks to enlarged film chambers.
The screw-thread type of fitting was chosen after long consideration of bayonet and other types. The mount is precisely M39 x 1/26" — i.e. 39mm diameter and 26 threads per inch. The flange focal distance was not standardized until the Leica I (Model C). The camera was released in 1930 but its great disadvantage was that each interchangeable lens had to be individually adapted to a specific camera at the factory and identified by having the camera's serial number (or the last three digits) engraved on each lens. Starting with the 1931 models, the Leica I (Model C) had a standardized flange focal distance of 28.8mm, which enabled all lenses to be used on all cameras.
The interchangeable LEICA lenses were offered in a large variety of types, ensuring excellent results in all branches of amateur photography and most specialized professional work. Their exceptional light-gathering qualities, resolving power, remarkable depth of field and unexcelled color rendition helped to develop the LEICA system of photography. All LEICA lenses (with the exception of a small number of the earliest models) were constructed so that they automatically attached to the focusing range finder.
Most of the 50mm lenses were of the "slip-out" variety, hence when not in use they were nearly flush with the front of the camera. This made it possible to retain these lenses on the camera regardless of whether the camera is placed in the pocket or case. The lenses had an ingenious infinity lock. In order to release the lens for other distances, the lens-control knob was pushed slightly inward and down. This feature enabled the camera to be used for infinity scenes and subjects without danger of the lens becoming accidentally out of focus due to unintentional movement. This feature was especially valuable to aerial photographers, for in this work vibration often shakes the lens away from the infinity position .
The film material used in the LEICA was the standard 35mm cinema film stock, obtainable all over the world. The LEICA does not make movies, but individual negatives 1 x 1 1/2 in. Up to thirty six exposures can be made with one loading. Film material for the LEICA is put up in daylight loading and unloading cartridges, making it very easy for the LEICA owner to load and unload his camera.
Many accessories for the LEICA were available. The more important ones for general photographic purposes were sunshades, filters, exposure meters, eveready carrying cases, developing tanks, paper easels, and enlargers, but for those who wished to become more ambitious photographers, panorama devices, remote shutter controls, rapid winders, viewfinders, and photoflash attachments were available.