[Leica] Re: Facts revisited

[Jim Brick <jim_brick@agilent.com>]

Well... as I stated yesterday:

"Unlike most of us, Erwin does not post ad hoc dissertations to the LUG
without doing the necessary research.

I do not know anyone who researches photography more carefully than Erwin.
This IS Erwin.

It is ironic that someone will believe the ad nauseam banter that kicks
back and forth on the LUG, but when a meaningful, ad hoc statement, is
delivered, it is immediately suspect.

I believe suspect only to those who wish the facts were different. But not
suspect to those who know Erwin and have no agenda to promote or wishes to
fulfill.

Jim"



At 03:10 PM 5/10/01 +0200, imxputs@ision.nl wrote:
>I am always surprised that anyone on this list can make statements without
any 
>proof or with reference to that famous " highly knowledgeable and offiial,
but 
>anonymous sources" phrase, without being challenged or asked to substantiate. 
>If I make a statement or do a measurement, my person is made suspect, my 
>methods are challenged or I am forced, preferably by legal means, to dsclose 
>sources by name, rank and position, I have to give quantities checked, any 
>individual serial numbers and if I have to to obey to Stephen Gandy's
demand I 
>am not even qualified to make any statement unless I can proof I am a working 
>optical designer with 20 years of practical experience and should have in 
>addition an masters degree in mechanical precision engineering before my 
>remarks gain a modicum of respectibility. 
>Now if these in itself reasonable demands would apply to all members of the 
>Lug, it would die instantly. But such is the force of demagogy that rules are 
>for anybody but the person who makes the rules.
>Now on topic:
>The Konica facts have as source the Konica Headquarters Europe, in Germany. I 
>spoke to the service people there, who reproduced wordly (from the English 
>specification details) that the film register is 28.00mm plus/minus 0.03.
>He also noted that it is impossible for any company with engineering quality 
>status as Konica or name anyone else, to depart from that figure
significantly.
>He said that it is possible to match a Konica body to Leica lenses, BUT then 
>you need to adjust the Rangefinder mechanism too. It is not enough to change 
>the boyonet, if that could be done. 
>He admitted that sometimes a user with a Konica body does not have problems 
>when using leica lenses but that it not generally the case.
>End of discussion.
>To resume my remarks.
>I know of Hexar RF bodies that depart from the quoted specs. I do not know
why 
>that happens or whether these bodies have been adjusted individually.
>I do know that I do not trust the wellknown visiual inspection method: I shot 
>pictures with a Hexar/Leica combo and see no problems. 
>I know and again here Stephen Gandy will object, that handheld shooting will 
>degrade te optical potential quality of a lens in such a way that no reliable 
>conclusions can be based on this experience.
>To give figures: based on the formula to be found in any handbook of optics,
>that a defocus of 0.2mm will reduce the definition and contrast of a lens in 
>the same proportion as handheld shooting can do.
>To be precise: if the optimum quality of a lens is 100 lp/mm, then a handheld 
>shooting can reduce it to 20 lp/mm with low contrast. A defocus by .2mm will 
>also reduce the optimum to 20 lp/mm. This being the case, any test with 
>handheld shooting will mask the defocus reduction.
>
>Erwin