Archived posting to the Leica Users Group, 1998/11/28

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Subject: Re: [Leica] Dominique's comments about fairness (very long)
From: Dominique PELLISSIER <>
Date: Sat, 28 Nov 1998 17:00:28 +0100

At 14:58 28/11/98 +0100, Erwin wrote :

First of all, Dominique, I am well aware that the edge spread function
approach for image analysis, has been developed by Leitz, more to the
point by Mr. Thomas from the Leitz Rechenbüro (Optic Design 

Comment : I'm not quite sure Mr Thomas would appreciate your  previous
valuation :"Let me be quick and mercifully: this 'edge spread width
criterion' does not exist".

The ethical problem is that, when you criticize a method, there is no way
for the defender to answer. On the contrary, when I write that one of
your statement is neither fair nor academic, you can reply.

As an example, see the answer of a researcher after I criticized  his
paper :

<smaller>From: Tamim Bayoumi <<TBAYOUMI@IMF.ORG>


Subject: your paper on a formal model of OCA -Reply

Content-Disposition: inline

Thanks for the question. I do not think the algebra is written very well,

you confusion is understandable.

Sigma squared j - 2 sigma jk + sigma k is the variance of the sum of 

two shocks. It rises with the variance of the original shocks and falls

with their covaraince. The root of this is simply the standard error of

sum of the shocks. 

The half operated on the entire square root, which is why in the last

of the algebra it cancels with the 2 in the 2 phi zero term.

Tamim Bayoumi

Rm 5-320


You wrote :

I am not aware that I gun down or condemn "once more" a research or a
method which has been made by others than you. That's neither fair nor
academic.I have clearly stated in all my posts around this evaluation
topic, that I know and appreciate the methods used by PopPhoto (in fact I
am quite alone in defending the SQF as a valid approch), that I know the
MTF measurements by ColorPhoto, Photodo and Chasseurs.

Comment : in a previous message (Date: Mon, 23 Nov 1998 23:49:03) you
wrote exactly the opposite : "BTW: PopPhoto uses this Ealing measurement
apparatus too. Most Lugmembers are not satisfied with or convinced that
the popphoto results are meaningfull. So here we have at least four
companies (popphoto, cdi,photodo, leica) using the same testing
equipment. Why should we believe cdi or photodo while we disbelieve

You wrote :

Now that was the explanation demanded by you. Eric does not want me to
take things personally . Still I feel a bit annoyed by your tone: "gun
down" "not fair or academic" especially as these accusations are made
without any knowledge of my way of work or background.

Comment : I asked you previously your methodology. 

You wrote :

 Also your demand: "(why ? I'm waiting for a rational

explanation)" sounds quite agressive to me. Why should I have to explain
indepth my statements to you where you never have given any explanation
about your statements or claims besides citing other sources.

Comment :I beg your pardon, Sir, but YOU are the first to impeach. I've
NEVER charged Chasseur d'images, Photodo, Popphoto or Erwin Puts with
misusing MTF analysis.

I think that the more tests there are, the more consumers will be
informed and will become hard to please with idiotic ad.

So you have your place among the testers and I recognize that I
appreciate your work and your I appreciate Chasseur

Dominique Pellissier