Re: filmscanners: Re: Emulsion flaws

[Arthur Entlich <artistic@ampsc.com>]

No, until recently, I never heard of bubble problems in standard film
print or reproduction processes, but I've suspected it in terms of a
consumer grade scanner problem for some time.

The mysterious black dots that sometimes show up by the hundreds or even
thousands on a scan which appears to have no dust (in fact, these dots
are way too small to be standard "dust")
and yet also do not appear to have other processing defects (such as
contaminated chemistry imbedding some solid matter) have led me to
believe there is something in the nature of some film scanners in terms
of either optics on CCD sensitivity which leads to these otherwise
invisible defects to showing up within the scan.

These small bubbles might be the cause.  Further testing would have to
be carried out to determine if the black dot positions coincide with the
larger bubbles.

Something is causing those tiny black dots. What, is still a relative
mystery.

Art



Austin Franklin wrote:
> 
> > Using very careful
> > lighting and focussing, I now see that the "bubbles" are indeed
> > present in undeveloped film.
> 
> I'm curious.  Has anyone ever heard that this is a "problem" previously?  I
> mean, film has been around for decades...as well as exceptional cameras,
> very good enlargers, and enlarging lenses...and people (including my self)
> have made some very large prints....but never have I heard anyone, out of
> hundreds of high end professionals and amateur photographers I know, ever
> mention "emulsion bubbles" as being a problem...
> 
> I've also not heard any of the high end scanner people I know (who use drum
> scanners, Leafscans and Imacons) ever mention this issue either...