Archived posting to the Leica Users Group, 2005/01/26

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Subject: [Leica] adhesives
From: jbcollier at shaw.ca (John Collier)
Date: Wed Jan 26 05:38:41 2005
References: <E57F8E01-6E95-11D9-AC8D-000393848332@total.net> <01ECFACC-6EF2-11D9-A98E-000A95DD7D76@charter.net> <6.2.0.14.2.20050125200520.030a9eb0@mail.screengang.com> <A2223394-6F57-11D9-8DFE-000D933BB53E@shaw.ca> <25CCF75E-6F64-11D9-B284-0003938C439E@btinternet.com>

I agree that the same level of precision was possible but I know from 
experience that it is now more consistently realized. I have not had to 
return a single modern lens due to suspect optical performance. With 
older lenses there can be significant variation from lens to lens. I 
have had a few turkey Leitz lenses.

John Collier

On 25-Jan-05, at 11:33 PM, Frank Dernie wrote:

> Adhesives are widely used in almost every engineering discipline now. 
> It is lighter and cheaper and plenty strong and accurate enough. I do 
> not agree that the recent lenses are necessarily better than older 
> because of modern machining though. They certainly no longer need 
> massively skilled technicians to assemble them, but the old stuff, 
> hand assembled, shimmed and carefully inspected during assembly should 
> all be the same as each other within similar tolerances to recently 
> lenses, it just takes more manual skill and time to achieve the same 
> level of consistency.
> That is not to say the recent designs are not optically better, my 35 
> f1.4 aspherical is comfortably the best 35mm lens I have ever used, 
> obvious even on the RD1, it is just that my experience of precision 
> mechanics shows me that it is much cheaper and less skilled to reach 
> the same level of precision nowadays than 30 years ago, but the final 
> level of precision is no greater today than then. Materials, OTOH are 
> hugely better today than then.


In reply to: Message from mjblug at total.net (Michael Blugerman) ([Leica] adhesives)
Message from s.dimitrov at charter.net (Slobodan Dimitrov) ([Leica] adhesives)
Message from rangefinder at screengang.com (Didier Ludwig) ([Leica] adhesives)
Message from jbcollier at shaw.ca (John Collier) ([Leica] adhesives)
Message from Frank.Dernie at btinternet.com (Frank Dernie) ([Leica] adhesives)