[filmscanners] Re: Scanner Profiling

["Karl Schulmeisters" <karlsch@earthlink.net>]

More than that.

Noise is most visibly perceptible in highlights
Noise occurs in the detectors n the darkest parts of the scan

For a film positive, the highlights transmit the most light and hence are
least susceptible to noise
For a negative, the highlights correspond to the densest regions of the film
and are most susceptible to noise.

----- Original Message -----
From: "Doug Franklin" <franklin@shootingshark.com>
To: <karlsch@earthlink.net>
Sent: Tuesday, July 15, 2003 7:25 PM
Subject: [filmscanners] Re: Scanner Profiling


On Tue, 15 Jul 2003 21:00:04 -0230, michael shaffer wrote:

> What difference does it make if the film is negative or positive?
> All the scanner understands, and scans, is color ... the rest of
> it is in software.

Because the positives (slides) don't have a mask layer, and they all
come out to colors that are directly viewable (perceivable), and they
all come out in the same color space: that of the human eye.  Negative
films, however, do not.  The (orange) mask layer is different from film
to film, and must be subtracted out before the "mechanical" color
inversion takes place.

TTYL, DougF KG4LMZ


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