Balderdash! The surface of the lens is smooth to within 1 millionth of
an inch (probably about 1/8 wave) but the thickness of the glass is
nowhere so closely controlled since it's not mechanically measurable to
that kind of precision. Whether one could repolish and maintain the
precision I think would depend on what was wrong with it in the first place.
Chuck Norcutt
usher99@xxxxxxx wrote:
>
> Wow this list is fast. I was to provide the same suggestion. I think
> they recoat as well, as the heat will vaporize some coatings. They did
> get back to me regarding a fungus etched lens--wasn't worth the cost to
> fix. 250 f2 maight be another story.
> http://www.focalpointlens.com/fp_intro.html
>
> Even a minor repolishing can wreck the optics according to Zeiss: from
> the Zeiss site:
>
>
> "When a lens is “re polished” it is not the same as Zeiss intended. One
> of the greatest parts of the lens makers art is the final polishing.
> Every lens element was taken through a process of abrasive surface
> removal, starting with the final raw blank of optical glass. With each
> step the abrasive used became progressively finer. This entire process
> was calibrated so that when the final polish step was finished the lens
> would be at the optimum dimensions for the design within a few
> millionths of an inch. Just how fine was the final polish Zeiss used?
> Zeiss had, and probably still has, large underground tanks which were
> isolated from even the slightest vibration. These tanks contained
> absolutely pure water containing rouge (iron oxide), that had been
> ground to the final possible fineness. After a period of years the
> liquid in the tank would be carefully removed from the top. When this
> liquid was evaporated an incredibly fine abrasive would remain and this
> is what was used to apply the final polish to Zeiss lenses. This is how
> very fine the surface of a Zeiss lens is. It is fine within a millionth
> of an inch. When a lens is “re polished” in a repair shop the degee of
> fineness of the lens surface that results from re polishing there, when
> compared to the original Zeiss surface is like comparing a bolder
> strewn field to the surface of a mirror. Basically, a Zeiss lens that
> has been re polished is no longer a Zeiss lens; it has been turned into
> ordinary junk."
>
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> Mike
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> I posted a note to the Yahoo camera repair group on re-cementing
> elements and got this response
> -----------------------------------------------------------------
> Yes, go here:
>
> <http://www.focalpointlens.com/fp_services.html#lens_separation>
>
> If Zuiko used balsam, it should be repairable.
>
> If Zuiko used UV epoxy, well, it may be hard to separate the lens
> doublet. Maybe even impossible.
>
> Good luck
>
>
>
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