Re: [Leica] Rangefinder Cams (was Leica-Users List Digest V3 #114)

[Charles Babington <cbabing3@swbell.net>]

Paul,

Thanks for your comments on the rangefinder focusing cam subject.  I
guess I misunderstood the original remarks.  I see what you mean about
the difference in angle of engagement between my 40mm C lens and my 35
and 50 Summiluxes.  Like you, though, I've never seen any difference in
results on film.

My reference to "non-rotating" cam was to the arrangement in my 90
Summicron and 135 Elmarit lenses, where the lens mount simply has a
small plate that engages the wheel on the rangefinder arm.  This plate,
which is about a half inch wide and is connected to the focusing threads
that are an inch or two forward of the lens mount, moves only fore and
aft as the lens is focused.  There is no rotation to it at all - the
same point on the rangefinder wheel remains in contact with the plate
throughout the focusing range of the lens.

Cheers,
Kip Babington