[Leica] Leica 111c w/50mm F2.0 lens....

[ruben at rhodos.dk (Ruben)]

Sorry Marc, you are  right  - I did not want to state it as a universal 
rule - just point out that the scrathes are easier to detect in an arms 
lenght if you do not have any means of magnification - and yes you are right 
about the summarit - both my summarits are scrathed, one worse the other one 
just a litlle soft :-)
best Ruben


----- Original Message ----- 
From: "Marc James Small" <msmall@infionline.net>
To: "Leica Users Group" <lug@leica-users.org>
Sent: Saturday, September 10, 2005 12:20 AM
Subject: Re: [Leica] Leica 111c w/50mm F2.0 lens....


> At 12:11 AM 9/10/05 +0200, Ruben wrote:
>>The old lenses scratch easy - fine scratches is not easy to see when the
>>lens is mounted and not easy to see closely
>>demount the lens - hold it up against the light in an arms lenght and look
>>thru it both ways - you will se the fine scrathes enlarged and this way 
>>you
>>can better determine how serious these will affect your images. If every
>>thing else is ok on the camera - schutter curtains , times etc. it could 
>>be
>>a very nice buy!
>
> Ruben
>
> This simply is not true as a universal statement.
>
> The 1.5/5cm Summarit does scratch easily as it has soft-glass elements
> facing outwards but the other 5cm lenses are quite immune to such.
> However, Leitz was forced to use a soft "drip coating" technique from 1946
> until the Zeiss patent on vacuum-coating technology expired in 1960, and
> these coatings both scratch easily and are also subject to drying out.  If
> you examine the lens surface under magnification, you will see a "dry lake
> bed", and that is the problem.  (Have the lens recoated and Bob's your
> uncle, of course.)
>
> Marc
>
> msmall@aya.yale.edu
> Cha robh b?s fir gun ghr?s fir!
>
> NEW FAX NUMBER:  +540-343-8505
>
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>
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>
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