Archived posting to the Leica Users Group, 2004/09/27

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]
Subject: [Leica] Re: R 60mm and 50mm depth of field differences?
From: jcb at visualimpressions.com (JCB)
Date: Mon Sep 27 21:57:41 2004
References: <15500326.1096301177481.JavaMail.root@thecount.psp.pas.earthlink.net> <004001c4a4ba$4e523820$02004254@desktop> <BAY19-DAV17dZ06YO4O000315a7@hotmail.com>
 
At 04:36 PM 9/27/2004, eric wrote:
>Got me thinking about trying out a vanilla 50mm summicron.
>What is minimum focus for this lens?
>Is depth of field for similar f stop settings at similar distances quite 
>different ? (possibly a question that reveals my stupidity - but it needed 
>asking..)


If you move a little closer with the 50mm lens in order to make the image 
size on your film to be exactly the same as it was with the 60mm lens, the 
DOF between the lenses is exactly the same, at the same f/stop. DOF is 
based on image size on the film and f/stop. Not focal length. A 50mm lens 
at 10 feet and a 100mm lens at 20 feet exhibit the exact same DOF. The 
image size on the film is the same.

If you stand at the exact same distance from your subject, with both the 
60mm and 50mm, your image on film will be smaller with the 50mm lens and 
exhibit a bit more DOF. You can use DOF preview on your R camera to see the 
exact DOF.

The 50mm Summicron focuses to 20"

JB
Replies: Reply from jbilin at axionet.com (Jacques Bilinski) ([Leica] Re: R 60mm and 50mm depth of field differences?)
 In reply to: Message from telyt at earthlink.net (Douglas Herr) ([Leica] Great Oxendon Northamptonshire #1)
Message from geebee at geebeephoto.com (GeeBee) ([Leica] Great Oxendon Northamptonshire #1)
Message from leica_korenman at hotmail.com (eric) ([Leica] R 60mm and 50mm depth of field differences?)