Leica Lens Tests

["joe b." <joe@azurite.demon.co.uk>]

In message <2.2.32.19960518052858.006e6b04@gp.magick.net>, Eric Welch
<ewelch@gp.magick.net> writes
>>I am also interested in doing lens tests of Leica lenses. I have 
>>evaluated several different lens test systems (Modern Photo 1968 USAF, 
>>Edmund Sci Co, a third proprietary chart [can't remember name]) and the 
>
>My prejudice, but test charts tell you little about a lens's performance. If
>you can't test the MTF curves (big bucks), at various distances from the
>center to edge, curvature of field, astigmatism, coma, chromatic aberration
>and numerous other things, you aren't going to be able to tell which lens is
>"best." Even then, how are you going to know how to interpret it without a
>degree in optical engineering? The best test in the world is to go out and
>test the lens in the conditions you shoot in the most. The same light you
>prefer, and with the film you prefer. Check the results and then go from
>there.  There are no "objective" tests. All are subject to qualification.
 
Up to a point, I'm curious to know what tests show about Leica lenses,
but I take it all with a very large pinch of salt. (They're a bit like
getting a spectral or chemical analysis of a Rembrandt painting.
Interesting data but it doesn't tell you the important information- what
the painting looks like! If that is important to you, you actually have
to look at it to know.) 
I used to read lens tests avidly and chose lenses on that basis- up
until I got my first results from Leica lenses. Then I noticed something
very interesting; I'd been reading test results pertaining to Leica
lenses along with tests of everything else and never once had those
tests indicated the actual results Leica lenses give in practice!
Because they can't. There are qualities and characteristics of Leica
lenses that I like very much, (and cause me to prefer them, by a
considerable margin, to lenses that excel in magazine lens tests)- to do
with colour rendering and the rendering of out-of-focus areas and the
subtle "look" of the results, and these are the reason that I use them,
but those qualities and characteristics aren't measured by lens tests.
Lens tests just give you a set of measurements. They can't tell you what
the pictures will look like.
-- 
joe b.