RE: filmscanners: Glass slide mounts

["michael shaffer" <rarewolf@roadrunner.nf.net>]

Neil writes ...

> ... today I received a set of glass slides - Quickpoint- on the
> advice of others around the Internet. Fantastic. Unbelievable difference.
> I'm getting much better results, much sharper. ...
>
> One side effect though, maybe someone can tell me why this is happening.
> With a few slides, say 10%, I am getting this erm, multi-coloured circles
> and unusual shapes appearing on the slide. ...

  My guess is that they are interference colors which arrive back to your
eye after reflecting off the film.  Much like the color of a soap bubble,
different color with different soap-film thickness, the gap between the film
and glass is absorbing some wavelengths and passing others.  My guess is you
can apply pressure and change the color or remove the effect, but it comes
back.  I also imagine you can try mounting again and remedy the problem.

shAf  :o)