Re: Bears and Butterflies

[Wayde Allen <allen@xxxxxxxxxxxxxxxx>]

On Tue, 3 Dec 1996, Robert Long wrote:

> On Mon, 02 Dec 1996 18:57:05 +0000 (GMT), Wayde Allen wrote:
> 
> |The color shift is due to the interference between light reflected from
> |the top of the film and the bottom of the film.  The color you see is
> |related in wavelength to (twice?) the film thickness.
> 
> That could easily be true if we were talking about reflected light.
> But the film was being viewed by transmitted light.  By reflected
> light it just looked black while still on the aluminum substrate and,
> if I remember correctly, sort of navy blue once it was removed.

Hmmm ... guess I'd have to see what you got to get a better idea.  You
might still be seeing the result of destructive/constructive interference
of internal reflections, even with the transmitted light.  This would
change the color as the thickness of the film varies, but I don't know if
this is actually what you are seeing.

- Wayde
  (allen@xxxxxxxxxxxxxxxx)


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Topic No. 16