Archived posting to the Leica Users Group, 2003/08/26
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At 11:22 PM -0400 8/26/03, Afterswift@aol.com wrote:
>In a message dated 8/26/03 8:17:13 PM Pacific Daylight Time,
>telyt@earthlink.net writes:
>
>> Diffraction cannot be reduced. It's a function of wave mechanics and the
>> size of the aperture, nothing else. Other aberations can be reduced enough
>> so that the sum of the aberations and diffraction still makes an acceptably
>> sharp picture - depending on the size of the print, of course.
>>
>> Doug Herr
>------------------------------------
>Doug,
>
>I reckon that's what they did. I assume the object of this tradeoff was a
>marketing promotion.
>
When film has grain the size of (small) golf balls, diffraction is
less of an issue. With current films, diffraction makes f/32 on 90mm
Elmars useless. Recompose, tighten up your criteria and use f/16.
There is good reason for the current 90/2 AA Summicron not having an
aperture smaller than f/16. Why purchase a superlative lens and then
use it to make fuzzy images? Even at f/16 it produces its poorest
quality.
- --
* Henning J. Wulff
/|\ Wulff Photography & Design
/###\ mailto:henningw@archiphoto.com
|[ ]| http://www.archiphoto.com
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