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Is it possible to have a lens recoated??

Started Jun 27, 2005 | Discussions thread
MitchAlsup Veteran Member • Posts: 5,518
Agreed

mbaginy wrote:

But to accurately answer your question - yes, it is surely
possible. But at an astronomic price.

You need to recognize that these coatings are applied in a vaccum and are only fractions of a micron thick (dozens of atomic layers thick). The lens needs to be complete disassembled down to the lens elements. The elements need to be cleaned.

Most coatings do not have a slovent that does not also disolve the glass itself, and to remove old coatings requires repolishing the surface!?! a horribly expensive operation if you do not have the equiptment on line to perform said polishing.

Many coatings need to be applied with the glass at elivated temperatures (200dC) in hard vaccum (10* -7 Torr) and the equiptment to do this is very expensive.

Multilayer coatings are chosen based on the refractive index of the glass being coated, so a coating (set) for a crown glass is wholy unsuitable for a flint glass or a Flourite or SD or ED,...

Basically, you are working with tollerances on the order of 1/4 wave length of light--or about 0.5 microns! This is tough work--don't get your coatings damaged.
--
Mitch

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