Archived posting to the Leica Users Group, 2005/06/28

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Subject: [Leica] New Puts article
From: jbilin at axionet.com (Jacques Bilinski)
Date: Tue Jun 28 19:25:21 2005
References: <21130191.1119744080947.JavaMail.root@wamui-backed.atl.sa.earthlink.net> <42BE3B7B.1070105@axionet.com> <20050626053302.GB7227@panix.com>
 

Rei Shinozuka wrote:

>correct.  for example, the 4x5 2.8 xenotar has approximately the
>same DOF as the Noctilux in 35mm.
>
>  
>
As I've said before you can use the 'crop factor' to convert the f-stop 
between different size formats to determine how same size prints will 
look with respect to DOF. . So an  f 1.0 lens in 35mm converts to an f 3 
or f4 in 4x5. This is consistent with Rei's results. I know it sounds a 
bit bogus, but it's a consequence of the DOF in the final print being 
affected only by the absolute aperature (diameter of the entrance pupil, 
not the f-stop) and not by the focal length of the taking lens or the 
film/sensor size.
In reply to: Message from hlritter at mindspring.com (hlritter@mindspring.com) ([Leica] New Puts article)
Message from jbilin at axionet.com (Jacques Bilinski) ([Leica] New Puts article)
Message from shino at panix.com (Rei Shinozuka) ([Leica] New Puts article)