Archived posting to the Leica Users Group, 2001/01/17

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Subject: Re: Body focus was [Leica] RE: Cosina still at it
From: Martin Howard <howard.390@osu.edu>
Date: Wed, 17 Jan 2001 13:56:15 -0500

Dante A. Stella jotted down the following:

> Think of the 200 parts in an M rangefinder.  Add up all of the individual
> tolerances.
> 
Yeah, but some are positive and some are negative and so they balance each
other out to some degree.  Besides, there must be a tolerance for the focal
plane too: it can move back and forth by some (small) measure and we will
not be able to see the differance in the negative/print.  As long as the
individual tolerances balance out to within this range, then everything's
fine.  Which, I'm assuming, is standard mechanical engineering practice.

> If you think otherwise, mount a very heavy lens on a rangefinder.  Line up
> infinity. Flip it upside-down.  Notice anything?

So what, don't use a Leica M in microgravity?  How many people do you know
who use their rangefinder cameras upside-down?

> -- Finally, any combination of the above.  This is the "system tolerance."

But isn't the job of factory QC and aftermarket CLA to ensure that the
"system tolerance" is within spec?

I think the solution is simple.  Grab a camera and one lens.  Grab 20 rolls
of film.  Walk the streets for 10 hours.  Take pictures.

M.

- -- 
Martin Howard                     |
Visiting Scholar, CSEL, OSU       |    What boots up must come down.
email: howard.390@osu.edu         |
www: http://mvhoward.i.am/        +---------------------------------------

Replies: Reply from Dan Cardish <dcardish@sympatico.ca> (Re: Body focus was [Leica] RE: Cosina still at it)
Reply from "Dante A. Stella" <dante@umich.edu> (Re: Body focus was [Leica] RE: Cosina still at it)