[Leica] Re: Erwin's tests

[Jim Brick <jimbrick@photoaccess.com>]

This is very commendable and when possible, one should look closely at the
results one obtains with the lenses that one owns.

HOWEVER...

Not many people have the connections to be able to borrow a 70-180 APO
zoom, or a 180/2 APO, or a 90 ASPH APO, or a 24 ASPH, or a 135/3.4 APO, or
a Noctilux, or a 35-70/2.8 APO zoom, or  a, or a, or a...

Erwin is testing all of the stuff that we all WANT, but have NO WAY OF
BORROWING, for the time required to...

"Have the camera on a tripod. One shot at each f-stop. As there are more
frames on a film than there a f-stops, you may wish to make two or three
series at different distances. Develop as you always do and make some
enlargements the largest size you normally make. There is normally no need
to make enlargements corresponding to all f-stops. Then compare with same
size enlargement (___ same subject___) from a negative ( same film, same
developer etc..)  made with a lens you know is good/excellent or whatever
standard you set."  ...whew!

Plus, not many people have a darkroom.

So this is NOT an alternative to Erwin's tests.

It is a good test, but basically made with gear you already have. Not gear
you might want.

Erwin's tests are scientifically user friendly. Using photographic terms to
describe optical performance. Just imagine the amount of time Erwin puts
into these tests. How many people, thinking about buying a new lens, have
the resources, time, and technical ability to do what Erwin is doing,
"before they buy the lens!" Very very few... I know of no one else.

I don't know about you, but I'm totally saturated with my regular work. I'm
ecstatic that I'm privy to Erwin's tests.

Erwin is an outstanding asset to the Leica community. Stop and think for a
moment, ,just how lucky we are.

Jim


At 12:06 AM 5/20/99 +0000, you wrote:
>Somebody wrote: "Me, I don't care; there's such abundance of information
>coming from him
>that no matter how careful he needs be with Leica management, the
>results of his studies remain most valuable. Or does anyone know of a
>worthy alternative to his tests?"
>
>YES I DO. Shoot a roll of film, the brand you use most. Make sure you have
>the camera on a tripod. One shot at each f-stop. As there are more frames
>on a film than there a f-stops, you may wish to make two or three series at
>different distances. Develop as you always do and make some enlargements
>the largest size you normally make. There is normally no need to make
>enlargements corresponding to all f-stops. Then compare with same size
>enlargement (___ same subject___) from a negative ( same film, same
>developer etc..)  made with a lens you know is good/excellent or whatever
>standard you set. You may look at the centre or the corners or wherever you
>want, or you may look for microcontrast or if squares look like cushions,
>or whatever, but look only for those things that are important to you. If
>you can not see any difference from one lens to another using this test
>method, then the difference is not important enough  _for you_   (...  and
>for this type of test I would not use that mini-skirted model that we  read
>about in an test announcement recently)
>
>>Thank you, Erwin, particularly for the "real world" commentary following
>>the testing results.
>>
>AGREED
>>