Archived posting to the Leica Users Group, 2004/08/31

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Subject: [Leica] Focomat V35
From: henningw at archiphoto.com (Henning Wulff)
Date: Tue Aug 31 22:30:57 2004
References: <BD5A969B.5627%mark@rabinergroup.com>
 
At 8:56 PM -0700 8/31/04, Mark Rabiner wrote:

><snip>



>And there are enlarger lenses which stop down not with a variable aperture
>with leaves, "the leaves" but with plates with perfect holes in them.
>Why This kind of thing is a big deal for enlarger optics over camera optics
>why I don't know. Maybe Erwin does. Or Richard Knoppow of the RUG. Or one of
>US even! Tom A?!

A perfectly circular stop ('Waterhouse' stop) has the least edge 
length for the amount of light passing, so diffraction effects are at 
their minimum. Diffraction is more of an issue in enlarging that 
taking, as a print with sharp grain and slightly diffuse objects 
looks 'sharper' than a picture that doesn't have sharp grain. f/22, 
and even f/16 can kill sharp grain in a print.

-- 
    *            Henning J. Wulff
   /|\      Wulff Photography & Design
  /###\   mailto:henningw@archiphoto.com
  |[ ]|     http://www.archiphoto.com
Replies: Reply from henningw at archiphoto.com (Henning Wulff) ([Leica] Focomat V35)
 In reply to: Message from mark at rabinergroup.com (Mark Rabiner) ([Leica] Focomat V35)