Re: filmscanners: grain in negs/slides

["Dave King" <kingphoto@mindspring.com>]

I wonder that myself, and speculate it may have something to do with
the base mask dye layer and some kind of "stacking" phenomena of
similar color dyes.  I've noticed that grain looks bigger (in scans
and looking directly at negs magnified on the light table) in the
areas where dye color is closest to the color of the base layer.  Blue
is formed by yellow dye for example, and yellow is close to the base
mask color.  I don't know if there are the same qualities we see
scanning when doing optical enlargements however.  Good quality
optical enlargement could serve as an accurate point of reference, and
separate digital artifact from actual properties of the films.  It
would be an interesting thing to investigate by doing exact
comparisons, but most of us don't have that kind of access to good
quality scanners and enlargers, and/or the time it would take to
conduct the tests.  Seems like it might be a good story for one of the
photo magazines.

Dave

----- Original Message -----
From: Tomasz Zakrzewski <tomzakrz@ka.onet.pl>
To: <filmscanners@halftone.co.uk>
Sent: Thursday, November 08, 2001 10:46 AM
Subject: filmscanners: grain in negs/slides


> Why do scans of color negatives appear grainier than those from
slides?
> I have always read and experienced myself that color negs are less
grainy,
> especially in high ISO emulsions and that in slides everything above
ISO 100
> shows pronounced grain (ok - naow we have Provia 400F).
> But from what you write and from my first set of scanned negs and
slides I
> conclude that negs really show more grain that slides. What's the
reason for
> this phenomenon?
> BTW the pronounced grain from my negs I don't consider intrusive in
any way.
> I'm just curious what's so peculiar in film structures that
different
> effects are achieved although both types of film use dye clouds.
>
> Regards
>
> Tomasz Zakrzewski
>