Re: Nikon/Canon rf lenses on Leica bodies????

[Marc James Small <msmall@roanoke.infi.net>]

At 06:34 PM 4/10/96 +0100, "joe b." wrote:

>I've heard of people using certain Canon and Nikon rangefinder lenses on
>Leica bodies, and so I called a shop here that sells vintage RF and
>collectable gear and which could be expected to know what fits on what.
>I asked if Canon and Nikon rf lenses could be used on an M6 with a
>screw-->M adapter and this person said, no, not at all, totally
>different mounts, only possible sometimes with specially made custom
>adapter and still there's the problem of rf coupling to worry about.
>He then went on to mention the "LeiNik" adaptor as an example of a not-
>very-good kludge and talked about how Leica lenses were superior and I
>should stick to them anyway... 

To be rude, these folks just don't know what in the daylights they're
talking about -- I'd recommend you stay far, far, far away from such a Pool
of Ignorance.

The Leica thread-mount has a thread of 39mm at 6 turns-per-inch with an
optical registration (back focus) of 28.8mm.  Canon adopted a near-equal
standard (they seem to have not understood that the pitch was in
turns-per-inch and their initial flange design was a bit off, too -- see
Dechert's Canon RF Cameras for a discussion).  From the first Postwar Canon
production, folks realized that (then relatively inexpensive) Canon lenses
could be fitted to Leica cameras, and the rest is history.  Late Canon RF
lenses (say, 1960 until production ceased in the early or mid 1970's, five
or ten years after the last Canon RF camera was made) will mount on a TM
Leica without a quibble, though earlier onces don't always do so due to the
difference in pitch and flange design.

Nikon soon followed suit.  Their design used a close (but not identical)
copy of Zeiss Ikon's bayonet mount;  by the time of the Korean War, Nikon
was producing their lenses in three mounts:  for Nikon RF, for Contax RF
(identified by a 'C' on the lower side of the lens mount), and in LTM.
Nikon ceased LTM production in 1958 or so and did a hellacious Fire Sale of
their remaining stock.

When Leica introduced the M-3 in 1954, they adopted a bayonet design with a
27.8mm back-focus, thus allowing the odd millimetre to be used for an
adaptor to fit LTM lenses to an M camera.  These adaptors have been made in
many forms over the years, but the best ones are the ones Leica themselves
produced from 1956 until 1966 or so (I don't have my catalogues at hand to
check the precise date):  these are the IRZOO/14097 for 50mm lenses, the
ISBOO/14098 for 90mm lenses, and the ISOOZ/14099 for 135mm lenses.  There
are an almost infinite variety of markings on these, some in centimeters,
some in millimetres, some with "28-50", some with "50", &c &c.  Used cost in
the US is about $75.

There are a variety of aftermarket adaptors, as well, including some Real
Flimsy Horrors from the Orient and some quite well-made ones such as the
135mm adaptor made by Heinz Kilfitt.

These adaptors will fit any LTM lens to any M camera.  Period.  If it is
rangefinder-coupled, it will almost always remain so when fitted to the M
camera.

Best wishes,

Marc
msmall@roanoke.infi.net  FAX:  +540/343-7315
Cha robh bas fir gun ghras fir!