sort of, but the optical path difference is due to a different refractive index due to stress rather than a different physical length. Chris Web Page http://www.chrisspages.co.uk/ |> -----Original Message----- |> From: owner-photoforum@listserver.isc.rit.edu |> [mailto:owner-photoforum@listserver.isc.rit.edu]On Behalf Of Achal |> Pashine |> Sent: 15 September 2003 18:58 |> To: List for Photo/Imaging Educators - Professionals - Students |> Subject: Re: Interference patterns in plastic |> |> |> Is this phenomenon same as Newton rings? |> |> |> |> ----- Original Message ----- |> From: "ADavidhazy" <andpph@ritvax.rit.edu> |> To: "List for Photo/Imaging Educators - Professionals - Students" |> <photoforum@listserver.isc.rit.edu> |> Cc: <andpph@vmsmail.rit.edu> |> Sent: Monday, September 15, 2003 8:59 AM |> Subject: Re: Interference patterns in plastic |> |> |> > > Could it just be my scan or will all plastics be goofified |> by polarizing |> > > filters? |> > |> > Greg, |> > |> > Just about any transparent plastic extrusion will show these |> "interference" |> > lines - they become even more noticeable if the subject is |> placed between |> > polarizing filters. Generally the problem manifests itself |> because these |> > subjects are not annealed (allowed to cool slowly) and have embedded in |> them |> > stress patterns established during the molding process. |> > |> > The colored lines are actually an indication that they were |> preferentially |> > passed by the on-camera polarizer while the rest of the colors |> were mostly |> > absorbed. So it not quite an interference effect in the |> classic sense of |> the |> > word. At least I think so at this time unless someone who really knows |> tells me |> > otherwise! |> > |> > cheers, |> > andy |> > |> > |> > |> > |> > |> |> |>
