> Well Gary, It looks like the LUG has been beating up your testing
> methodology a bit this week.
Methodology:
4. The tester gets significantly different results from mirror up and
diapghragm pre-fire. This means that the support is not all that
strong. If he is using the same support for his 'best' results the
assumption has to be that with further stability he could get even
better results. If I test lenses for my own purposes the support is
going to be steady/solid enough that the mirror, diaphragm, shutter
and trucks going by aren't going to make any difference. A whole
different order of support is going to be used. Otherwise I am
testing on the support, shutter, diaphragm mechanism, etc. and lens
as part of a system test, and I cannot/will not make conclusions
about the lens on that test. Have a look at the test of the 250/2
Zuiko. The excuse that this is a heavy lens and therefore hard to get
steady is absolutely no excuse. You just bolt it to some concrete if
you really mean to test the _lens_.
5. He views the film projected on a screen/surface with a (Rollei?)
projector fitted with a zoom projection lens. Not exactly state of
the art in analysis.
Fujichrome 64T is a decent enough film, but not the best either.
The net result of the methodology lapses noted (there may be others,
as he doesn't go into that much detail) means that most lenses will
be brought to a fairly low common denominator, which you can see if
you look at a number of the results. Except for a few deviations,
most lenses that you would expect to be useable end up with up with
one or three A's at the edges and a couple at the middle. The only
lenses that get significantly better results are some Zuikos. That
makes me a bit suspicious as well. Some are definitely excellent
lenses, but considering the results he achieved for an extremely good
non-Zuiko lens, the 90 A-A, the relative standings are suspicious.
Also note that many Zuikos got a top mark, or at least an A- at f/22.
If you only deal with what is theoretically possible, saying that no
lens achieved a better value at any aperture than what the best lens
achieved at f/22 means the bar was set too low.
I don't think these tests can be taken very seriously, even if you
are very satisfied with your Olympus lenses. I'm very happy with many
of my non-Leica lenses (which outnumber my Leica lenses by a wide
margin), but I try to be objective about what they can do for me.
I think all you can say that these are the results he obtained using
his methodology. Take it or leave it.
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|