[filmscanners] RE: Scanning negs vs. slides

["Austin Franklin" <darkroom@ix.netcom.com>]

> 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.

Hi Michael,

Yes, you're right about that.  It's true because slides are typically viewed
by human eyes, and therefore have to match the response curve of our
eyes...but it doesn't have to be that way.  If you are scanning the film and
can apply setpoints and tonal curves, that need wouldn't exist.

Regards,

Austin

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