Archived posting to the Leica Users Group, 2012/07/22

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Subject: [Leica] Some technical speculations re: rangefinder
From: amr3 at uwm.edu (Alan Magayne-Roshak)
Date: Sun, 22 Jul 2012 19:03:34 -0500 (CDT)

On Sat, 21 Jul 2012 Herbert Kanner <kanner at acm.org>wrote:

>... I said, ok, when you get closer, the lens has to move away from 
>the sensor/film. Now think about a pinhole, which could be thought of 
>as an highly stopped down lens. As the pinhole moves away from the 
>film/sensor, the angle subtended by same becomes smaller. So the 
>frame lines in the viewfinder should get closer to each other, making 
>a smaller rectangle.

>Good to be forced to think once in a while.

>Herb
======================================================================================================================================
The Konica IIIA and IIIM rangefinder cameras of the late '50's had the usual 
parallax correction, but also variable frame lines to compensate for reduced 
field of view  (but the lens was non-interchangeable so they could do this).

Alan

Alan Magayne-Roshak, Senior Photographer
UPAA POY 1978
University Relations
University of Wisconsin-Milwaukee
amr3 at uwm.edu
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/

"All the technique in the world doesn't compensate
 for an inability to notice. " - Elliott Erwitt