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

["Rob Geraghty" <harper@wordweb.com>]

"Roger Smith" <rsmith@unb.ca> wrote:
> Not only is the Fuji slide sharper, it shows relatively few,
> large bubbles compared to the Kodak slide. The Fuji bubbles appear as
> a few fairly obvious spots on a scan - easy to spot out in Photoshop.
> The Kodak slide when scanned shows a gritty, grainy appearance which
> is very hard to clean up.

I'm wondering whether this phenomenon has any connection with something
mentioned to me by a lab when I complained about water marks on Kodak 100VS
slides.  The water marks were rings that had expanded from the sprocket
holes on the film before drying on the surface - and ruining some nice
sunset photos.  When I spoke to the lab, they said that Fuji and Kodak films
behaved quite differently in that chemistry tended to sit in the sprocket
holes on the kodak film - resulting in the rings - but didn't on Fuji film.
It sounds to me like the surface tensions of the films are very different.
If the bubbles are forming on the surface of the film (in the same plane as
the dust) then perhaps the higher surface tension of Kodak film "bonds" more
bubbles to the surface than on Fuji film.

Roger, I gather the bubbles are on the emulsion side of the film, not the
base side of the film?

I never used 100VS again - partly because of the rings, but also because of
the strange colour shifts in some of the photos.   Fuji films tend to
oversaturate, but at least the colours look more sensible!

Rob