Re: [Leica] Focusing at infinity

[John Collier <jbcollier@home.com>]

I would not worry about this too much. I have a couple of M bodies and: with
one lens, they both register infinity when the lens is set to infinity; with
another lens, one registers correctly and the other just slightly before
infinity; and, with the next lens, they switch! There must be slight
differences in where each rangefinder lever roller touches each lens cam and
differences in how steep the lens cams are. Remember each lens cam is hand
finished. I was talking about this with the head repair chap at Leica Canada
and he related that some people send in their whole kit to have everything
labouriously hand matched. He thought this was a little excessive on the
customers part. If you are not experiencing focussing errors in the field I
would not worry about it; but, if it only affects one lens out of your
collection then I would send that one back to be checked. If I was was using
either the 50 Noctilux, 75 Summilux or the 90 Summicron, I would check each
lens by focussing on the tines of a rake and checking the negs/chromes to
make sure that it was dialled in wide open.

John Collier

> From: "Dale R. Reed" <dale-reed@worldnet.att.net>
> 
> Got a question for you all.
> 
> I have two M6 HM cameras, one for SCALA(B&W slides) and the other for color
> slides. I guess I have shot total 1000 photographs with the two cameras.
> 
> And I have quite a few lens stretching from 21mm to 135mm.  I have bought
> both new and used lens.
> 
> I was out trying to obtain a photo of a landing Boeings this afternoon with
> evergreen trees in the foreground and broken clouds and dim(in the bright
> afternoon sunshine) moon in the background. I was using my brand new 135mm
> lens.
> 
> I am pretty sure that when I turn the lens all the way to infinity the two
> moon images are still shifted from each other. In other words I can focus
> the lens at the nearer tree, or on the airplane, but(according the
> rangefinder) I could not turn the focusing ring far enough to focus on the
> moon.
> 
> I tried both cameras and other lens including my older(mechanically worn so
> a little bit loosey goosey) 135mm lens and they all focus just fine.
> 
> In fact at least one of my lens can be turned even farther past the position
> where the rangefinder says it is focused.  As I remember there was a
> discussion about this possibility a couple years ago on the LUG and what it
> meant.
> 
> So, the question is, do I believe my rangefinder and is there something
> wrong with the lens?  Or do I assume that it really is focused at infinity
> and ignore the rangefinder for this particular lens at long distances?
> 
> Of course after a few weeks of taking photos and getting the film developed
> I will find out for myself but I figured some of you folks will have had
> experience with just this subject.
> 
> Thanks for the advice.    Dale
> ---
> $ dale-reed@worldnet.att.net Seattle, Washington USA $
> 
> 
>