Archived posting to the Leica Users Group, 1997/07/22

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Subject: CI (Was: Elmarit/Summicron)
From: Francois Jouve <Francois.Jouve@polytechnique.fr>
Date: Tue, 22 Jul 1997 11:57:52 +0200 (METDST)

Dear Gerard (I dropped the E accent (') from your name, don't worry about my
C cedille, I am used to forget it when I am on the net)

Thank you for your advice. I think you are a little rude for the poor
Summicron 90. At least mine is very sharp. At F2, it's much sharper
than my Summicron 35 (BTW any precise informations about the new 2/35 Asph
vs. the old one ? Wake up luggers !)

Concerning Chasseur d'Images and the lens tests in general, see

   http://www.cmpsolv.com/photozone/

Here is a copy of what they say about CI tests:

- ---------------
Chasseur d'Image (France) 

      The Test System: 
      Judges optical performance, performance/quality for the price and the "Cote d'amour". The
      Cote d'amour represents the subjective opinion of the test crew. 
      The performance is tested by three methods: 
            test charts (with a reference well-known lens) 
            double resolution projector (for contrast, vignetting and distorsion) 
            MTF-tests up to 200 (!!!) lp/mm 
      The tests are adopted to the specific lens type.
      The overall performance is rated in stars for performance, Quality/price ratio, Love Factor: 
            * - weak 
            ** - average 
            *** - good 
            **** - very good 
            ***** - excellent 

      My Comment: 
      Based on their information I would judge their test system as excellent. Their final results are
      more or less always consistant though they seem to perfer some brands within their -textual-
      analysis - in regard to this point you should probably handle the mark for "cote d'amour" (=
      subjective opinion) with some care! A point to criticize is surely that they don't devide their bar
      charts into separate graphs for sharpness and contrast. The presentation of their results is
      probably too primitive for people who want to go in-depth. 
- ----------



> Fran=E7ois (hopefully the "C" cedille will make it through the net),
> 
> Could you shed some light on the lenstests of Chasseurs d'Images? What are
> their charts showing: contrast? resolution? A combination of both? How do
> they perform their tests? What equipment do they use? Any information that
> you can provide will be highly appreciated!
> 
> Answering your Elmarit-M versus Summicron question is easy: buy the
> Elmarit-M. Better images at any aperture and at any distance setting. The
> Elmarit-M is one of the better Leica lenses. The Summicron one of the worse
> (relative to other Leica glass, not relative to other manufacturers glass).
>
> Gerard Captijn=20


Hope this help

- ----
Francois Jouve (Francois.Jouve@polytechnique.fr)
Centre de Math. Appliquees, Ecole Polytechnique, 91128 Palaiseau (France)