Leica M3 1954-1966 The Leica M3 was the first model of the M-series (not the M2 or the M1) from Leica cameras, it was revolutionary at the time of it?s launch. From it?s release in 1954 to the end of its production (1966) about 220.000 cameras were built. The M3 was the first Leica introducing the bayonet mount, also called the Leica Mount, which lasts till today. 
This mount allowed the lenses to be changed quite faster, it also allows 100% lenses-compatibility with the previous screw-mount by the use of a simple adapter. The Leica M3 introduced an incredible viewfinder for the time it was released and even by today standards. It has an 0.92x magnification factor, and very bright 3 (three) focal distancies built-in frame lines, 50mm, 90mm and 135mm. The beauty of it is that the viewfinder frame lines change automatically when you swap lenses, yet there?s a switch on the front of the camera to do it manually, the 50mm frame line is always shown, this helps the photographer to make better compositions. 
Usage with other lenses, generally wider lenses (35mm), viewfinder adapter is required, this is also known as Leica Goggles. To advance the film Leica introduced a lever, up to serial number 915 251 the Leica M3 was a double stroke, afterwords this serial number a single stroke. 
This was accompanied by a frame counter (from 0 to 40) which reseted automatically when the film was changed. Maybe one of the most important characteristics is the way the film is loaded, in the Leica M3 it became much easier than previous models, the film is loaded by removing the bottom plate and raising the backplate yet the Leica M3 film loading is still slower than the Leica M4. The film is unloaded by setting a lever on the front of the camera to the "R" position pulling out the rewind nob and rotating it. On the backplate there is a film-type indicator with an ASA indicator. The shutter on the Leica M3 is just one, on previous models there were to shutters for low a high speed, it?s capable of speeds from 1s to 1/1000s + BULB. A lever for self-timer is also present in the front. 
Important links: Leica M3 Manual (PDF)
This mount allowed the lenses to be changed quite faster, it also allows 100% lenses-compatibility with the previous screw-mount by the use of a simple adapter. The Leica M3 introduced an incredible viewfinder for the time it was released and even by today standards. It has an 0.92x magnification factor, and very bright 3 (three) focal distancies built-in frame lines, 50mm, 90mm and 135mm. The beauty of it is that the viewfinder frame lines change automatically when you swap lenses, yet there?s a switch on the front of the camera to do it manually, the 50mm frame line is always shown, this helps the photographer to make better compositions. 
Usage with other lenses, generally wider lenses (35mm), viewfinder adapter is required, this is also known as Leica Goggles. To advance the film Leica introduced a lever, up to serial number 915 251 the Leica M3 was a double stroke, afterwords this serial number a single stroke. 
This was accompanied by a frame counter (from 0 to 40) which reseted automatically when the film was changed. Maybe one of the most important characteristics is the way the film is loaded, in the Leica M3 it became much easier than previous models, the film is loaded by removing the bottom plate and raising the backplate yet the Leica M3 film loading is still slower than the Leica M4. The film is unloaded by setting a lever on the front of the camera to the "R" position pulling out the rewind nob and rotating it. On the backplate there is a film-type indicator with an ASA indicator. The shutter on the Leica M3 is just one, on previous models there were to shutters for low a high speed, it?s capable of speeds from 1s to 1/1000s + BULB. A lever for self-timer is also present in the front. 
Important links: Leica M3 Manual (PDF)
