Re: filmscanners: Emulsion flaws (was dust in SS4000)

[Arthur Entlich <artistic@ampsc.com>]

How very interesting!

I am now more sure of my theory.  Either these bubbles occur during
manufacturing or processing, and are, I suspect, either introduced in
the base plastic or as the coatings are layered onto the film, or, the
processing creates some gas which doesn't fully migrate out of the
emulsion during washing and drying.

Art

Roger Smith wrote:
> 
> Martin and others:
>         This is another Roger (not Miller), but I have been following
> the "Dust" thread with interest.
>         I have often noticed tiny spots on my scans (particularly
> since I got a Minolta Scan Dual II, which shows the spots much more
> than my previous Canon FS2710).
>         I stuck a Kodak Ektachrome 64T slide (that I developed this
> morning) under my microscope and cranked up the magnification to
> 400x. The enclosed Nikon Coolpix 995 image taken through the
> microscope shows what I saw. This is an area of the slide which is
> almost transparent - the orange area at the bottom shows the film
> grain. The bubble-like flaws are in a different plane from the grain,
> on the outside layer of the emulsion. I can tell this by where I have
> to focus the microscope to see them.
>         I developed the film myself, using double distilled water for
> the final rinse. I must admit this is one of the worst examples of
> these bubbles I have seen, but they do show up on most of my slides,
> on many different types of film. I thought it might be the result of
> a processing error, but then I saw the same bubbles on a Kodachrome
> 64 slide from 1975.
>         Any ideas?
> 
> Regards,
> Roger Smith
> 
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>    emulsion_1.jpg    Type: JPEG Image (image/jpeg)
>                  Encoding: base64