Re: [Leica] Leica-Users List Digest V3 #114

[Summicron1@aol.com]

In a message dated 6/9/98 8:45:21 PM, you wrote:

<<focusing mechanism on the lens. If you compare the bit of metal that hits
the focusing cam, the CL lens has a much steeper cut as Leica claims.  I
cannot comment on how this affects focus, as I have not gotten that film back
from the lab yet, but stephen gandy (www.cameraquest.com) comments that the
focusing appears to work fine when mixing and matching lenses.>>

That "steeeper cut" is really a different sort of cam -- on most M lenses
turning the lens mount to focus moves a solid cam back and forth at an eve
rate-- accomplished by several sleeves of metal machined on threads together
so focusing the lens moves the cam against the little focusing wheel at the
same rate no matter which lens you use.

on the CL lens they eliminated that second cam to save weight. The "cut" is
machined at that angle so it moves the focusing lever precisely the same as
the other lens cam does. The only difference, which could cause
incompatibility to a degree, betwen the CL lenses and others, is that to use a
CL lens on an M the focusing wheel in the camera must be precisely centered so
it hits that machined section precisely. On the other M lenses centering of
that focusing wheel in the camera body is not so important, because the cam in
the lens is solid all the way across...as a moment's comparison, holding both
types of lenses and playing with their focus, will make clear.

if a CL lens on an M focuses correctly at infinity you are OK.

charlie trentelman
owner of both
ogden, utah