Archived posting to the Leica Users Group, 1999/03/25

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Subject: [none]
From: "Jean-Claude Berger" <jcberger@imaginet.fr>
Date: Thu, 25 Mar 1999 20:16:04 +0100

Hi Alexander,

About your question "accuracy, can you define that?", I post 
here a message I wrote for the Contax G User List last year. 
Later the same thread appeared on rec.photo.equipment.35mm 
so I think one can find it on Dejanews. As Lucien stated, 
it's possible that the poor results I got with G lenses are 
related to those focusing problems. I do understand that some 
G users never had those problems but I wish they could understand
themselves that others did have them.

Best regards.


"Some weeks ago [october], I bought a used Contax G1 set (45, 28, 90 mm). 
One day, I did the following experiment. I placed my G1 with the 90
mm on a tripod and targeted an easily autofocused cardboard. While
depressing the trigger several times, I looked to the top LCD
(measured distance indicator) and could read values ranging from 1.03
m to 1.07 m.

To be sure, I took the shots and pictures really showed focusing
inconsistencies. Same thing to another object that the telemeter
detected at 1.89, 1.91, 1.93, 1.90, 1.88 and 1.93 m. Well... Let's now
try with the 45 mm. Same problem !! The distances were more consistent
but I could observe some differences of 1 or 2 cm when focusing at 1
meter.

I changed the G1 body and the 45 mm where I bought them but the new
set had the same behavior. I kept it, though, because the contacts
between the body and the lens seemed cleaner (the lens mount design is
a shame ; if you are not very careful when you change lens, you can
severely damage those contacts).

I did read several times that a return to Kyocera would solve the
problem and I prepared myself to send them the G1 for tuning

But, before that, I went to a reseller and asked to try the G2. With a
new (and recent) body and a new 90 mm, I could observe the same
problem than with my used G1. From that moment, I loved my Contax set
a little less.

Some days after, I was finishing a little walk when I saw a very
interesting pattern in a stone wall. I mounted the 45 mm on the G1,
composed carefully, checked the exposure parameters (something like
1/500 s at f:5.6) and took the shot. It was the last picture of the
roll, I did not doubled it.

When film came back from the lab, I could see this last picture
completely out of focus (no, it's not a motion blur). As soon as I
could, I sold back my Contax set, sadly."


- -- 
Jean-Claude Berger (jcberger@jcberger.com)
Systems and RDBMS consultant (MCSE)
Lyon, France
http://www.jcberger.com