[Leica] Re: High resolution Zeiss lens

[henningw at archiphoto.com (Henning Wulff)]

At 7:28 PM -0500 3/8/06, lrzeitlin@optonline.net wrote:
>  From: "subminiature" <subminiature@ntlworld.com>
>Subject: Carl Zeiss news on Spur 400 lp/mm on film
>
>
>http://www.zeiss.de/C12567A8003B58B9/?Open
>
>Then select
>   Camera Lens News 24
>
>Latest Newsletter Issue,
>February 2006
>
>Gourmet Food for ZEISS IKON
>A camera system capable of extraordinary resolving power asks for adequate
>image recording media ...
>
>Resolving Power Record with ZEISS Biogon T* 2,8/25 ZM
>
>"The high resolution film of choice was the SPUR Orthopan UR supplied and
>processed by SPUR.
>
>The result was a whopping 400 lp/mm on film, recorded with the Biogon 25 at
>f/4 in the center of the image. This value, 400 lp/mm, corresponds to the
>maximum resolution theoretically possible at f/4; in other words it
>represents the calculated "diffraction limited" performance at this
>aperture. It is noteworthy that this test was conducted with a production
>lens on a production camera, indicating that the film was precisely
>positioned and flat."
>
>--------
>
>This figure is astounding
>and has the same relevance to ordinary photography as deep sea 
>diving has to splashing around in the pool. Extraordinary resolving 
>power, at near the maximum theoretical limit, has been possible for 
>some time using monochromatic light and lenses computed for the 
>specific object and image distances. Some are used in 
>photolithography in manufacturing computer chips, others in spy 
>satellites. But if you read the full text you will find that this 
>resolution is available only in the center of the field with special 
>ASA 25 emulsions. According to the Kodak catalog, film usable for 
>general photography has a maximum resolving power of 125 lp/mm or 
>lower. Most of us also enjoy taking pictures of multicolored three 
>dimensional objects at varying distances and find the esthetics of 
>flat resolution charts to be lacking. But I suppose it makes good 
>advertizing copy. I wonder what the bokeh of the Zeiss lens is.
>
>Larry Z

For a film/lens combination to resolve at the theoretical limit of 
the lens, the film would have to have infinite resolution and 
contrast capability (no transfer function losses) and the lens would 
have to be perfect, which no aberrations  and over the full visible 
spectrum.

Treat this announcement with a bit of scepticism.

-- 
    *            Henning J. Wulff
   /|\      Wulff Photography & Design
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