[Leica] Don's PAW 25 de plane, de plane

[henningw at archiphoto.com (Henning Wulff)]

At 10:58 PM -0500 6/15/04, <robertmeier@usjet.net> wrote:
>Don,
>
>The 21 SA repeals the laws of optics?   Something circular in the corner of
>the frame does not become an oval with the 21 SA?   Please post a picture to
>show this miracle.
>
>Bob
>
>
>>  As you already know, the 21 SA has just about zero distortion: you can
>>  put something in the corner and it will look normal.  One of the reasons
>>  I put up with the relative slowness and the lack of metering with an M
>>  is the absolute fabulous performance of this wide angle.
>>
>  > Don

Puhleeeze.

'Distortion in a lens' in common usage refers to linear distortion, 
not perspective distortion. With respect to linear distortion, the SA 
is about as good as any lens of this focal length is or has been.

If you want to talk about other 'distortions', you should start out 
from the primal fact that imaging an infinite 3 dimensional space 
onto a limited 2 dimensional space will produce many types of 
distortions. These are not per se lens distortions, but distortions 
arising out of the above parameters.

All lenses produce distortions; the SA just produces way less linear 
distortion than most of that focal length.

-- 
    *            Henning J. Wulff
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