juza
Wondering Monkey
still comfused with this too. thanks
difference between M mount and Screw mount on a Leica?
- Thread starter juza
- Start date
- Latest activity Latest activity:
- Replies 5
- Views 3K
peterm1
Veteran
The screw mount is, as its name suggests, a lens mount which you screw on - by turning the lens clockwise onto the camera body. If you are familiar with the Pentax Spotmatic camera - same principle. It is sometimes referred to as an S mount or a LTM (Leica Thread Mount) mount. The M mount quite simply is a bayonet mount - exactly the same (in principle) that you find on modern SLR cameras with interchangeable lenses. Thats it. Simple really. The LTM mount was something of a standard in its day and quite a few cameras of other manufacturers used the same mount (Canon for example.) Not so with the M mount. By the time it came into being in the mid 1950's, the SLR camera was just starting its rise to predominance so I suppose this may be why Leica's particular version of the bayonet mount - the M mount never became too widely used - it was designed for rangefinder cameras not SLR cameras. Today there are a few 3rd party manufacturers of M mount lenses and of course you can also get adapters that allow LTM lenses to be used successfully on M mount cameras.
ltketch
Established
They are two totally different mounting systems as Peter explains. The M mount though was not widely used because of patent rights. Like the other bayonet mounts, it was a patented system to mount the lens to the camera and could not be used by other manufactures. In the 1970s Leica allowed Minolta to produce lenses in M mount for the CL and CLE, and in the 90s when the patent rights ran out, along came the Hexar RF and Bessas.
Andy Aitken
Registered Loser
What is important to understand is that - unlike with most other camera systems - a leica screw mount (aka ltm, L39) lens fitted with an adaptor and used on an M mount camera suffers no loss of functionality whatsoever. Therefore almost all ltm lenses going right back to the 1930's can be successfully used on any M mount camera up to and including the M8. Which is kinda handy.
Dralowid
Michael
It is worth noting that an M mount camera is thinner than a LTM (screw) mount camera. (by thinner I mean lens flange to film distance)
Therefore a screw mount lens will fit on an M mount camera with adaptor but an M mount lens will never fit on a screw mount camera and focus to infinity.
Furthermore, although in theory you can use some SLR lenses on M or LTM cameras with adaptors (uncloupled for rangefinder), M and LTM lenses are only useable for macro work on SLR cameras which are generally much thicker. This last may not apply to Leica lenses over 65mm that were made for the Visoflex system and had removable optical units.
Michael
Therefore a screw mount lens will fit on an M mount camera with adaptor but an M mount lens will never fit on a screw mount camera and focus to infinity.
Furthermore, although in theory you can use some SLR lenses on M or LTM cameras with adaptors (uncloupled for rangefinder), M and LTM lenses are only useable for macro work on SLR cameras which are generally much thicker. This last may not apply to Leica lenses over 65mm that were made for the Visoflex system and had removable optical units.
Michael
Similar threads
