[filmscanners] RE: Scanning negs vs. slides

["michael shaffer" <michael@shaffer.net>]

Austin writes ...

> ...
> Optical density and "number of f-stops" that film records aren't directly
> related.  You say that negative film, which has a LOWER optical density,
> records more f-stops...so how is the optical density limiting the
> number of f-stops?

  I claimed for "slides" the number of f/stops is related to density.  That
is, for viewing the the f/stops as imprinted on positive film, there does
need to be a direct correlation with film density.  If you tried to
expose/develope for slide density to include more f/stops, then the viewed
image would not match the original scene's contrast ... it would appear
flat.  Negatives are not "viewed" this way and can be
engineered/exposed/developed for optimizing dynamic range.

cheerios ... shAf  :o)
Avalon Peninsula, Newfoundland
www.micro-investigations.com (in progress)

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