Archived posting to the Leica Users Group, 1996/07/29

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To: leica-users@mejac.palo-alto.ca.us
Subject: Re: Leitz/Minolta CL: Question
From: "Roger Beamon" <beamon@primenet.com>
Date: Mon, 29 Jul 1996 05:25:48 +0000
Comments: Authenticated sender is <beamon@mailhost.primenet.com>
Priority: normal

>Well Eric, perhaps you don't understand that a shortening of effective RF baselength 
> doesn't always lead to a perceptible difference in focusing accuracy.   Take for 
> instance the difference between the M3 finder and the M2/4/5/6 finders.  While the RF 
> baselength is the same, the effective baselength has been reduced from .9 in the M3 to 
> .72 in the later cameras.   Theoretically it may make a difference, but real world it 
> makes very little  and Leica was obviously comfortable in making that reduction without 
> unduly sacrificing accuracy.   The surprise isn't that that the CLE would be more 
> accurate,  but that the difference in accuracy would show up in a real world test over a 
> lens range as short as 28 mm and 40 mm.

Effective RF base length *always* makes a calculable difference, 
other things remaining equal. The whole photographic system with its 
multitude of variables, may, indeed, make the differences 
undetectable. Another operator, however, with less reproducible focusing 
skills probably will achieve greater focusing precision with the 
longer effective base; again, other things being equal.  
--
Roger Beamon,  Naturalist & Photographer
                          Docent: Arizona-Sonora Desert Museum
                          Leica Historical Society Of America
                          INTERNET: beamon@primenet.com