P3D Anti-Newton Glass

[emdesher <emdesher@xxxxxxxxxxxxxxxxxxxx>]

Anti-Newton glass has been used to prevent the formation of the 
irregularly shaped rainbow hues sometimes seen in glass mounted slides.  
It is caused by the contact of the film with a glass surface.  It is a 
very noticable and objectionable problem.  Whenever the film curves or 
buckles there is the chance of Newton's rings forming.  This is why the 
RBT mount has to use an anti-Newton ring type glass since there is no 
room to space out the glass and the film.  Often the emulsion side of the 
stereo pair is irregular enough to avoid rings from forming.  In humid 
climates, it is typical for slides to have Newton's rings.  Anti-Newton 
glass is a cover glass given an additional treatment: it is exposed to  
acid flumes which partially eats away some of the surface.  The surface 
is no longer perfectly flat and smooth, but actually has microscopic 
ridges which act as minute projections to physically space the film away.
Because of the health danger to the workers, this acid treatment is 
offered by very few companies today.
Please see my listing on Sell 3D for the last of my anti-Newton glass 
stock or email me directly.  Dennis Sherwood   emdesher@xxxxxxxxxxxx


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