Archived posting to the Leica Users Group, 1997/12/29

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Subject: Re: [Leica] Importance of Coating Flaw?
From: Marc James Small <msmall@roanoke.infi.net>
Date: Mon, 29 Dec 1997 23:25:38 -0500

At 07:25 PM 12/29/97 -0500, Ed Meyers, who really knows better, wrote:
>Anyway, I think that with modern technology and very high
>prices, the lens you describe should be bubbleless. Ernst would
>roll over, if he knew that his lenses had bubbles in them. Ed

Hmm.  Speak to some glass chemists.  The annealing of quality optical
glasses is a problem, as bubbling during the cooling stage is a common
occurrence.  Zeiss was challenged on this for years and had a flier they
would send out in the Prewar days showing that the bubbles made no
measurable difference.

No, Ernst wouldn't be upset.  Nor Carl, nor Otto, nor Joseph, nor Max.  The
problem is endemic and hard to beat.  Modern mixing techniques have reduced
the problem but not eliminated it:  in the very finest optical glasses, it
still occurs.

Marc


msmall@roanoke.infi.net  FAX:  +540/343-7315
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