Austin wrote:
>I don't believe film base opacity is standardized...so different films
>would yield different DMin.
That's true. But they'd also start with a different DMax, with more than the
density of air. The dynamic range would (or should) remain nearly
constant--although the values are admittedly not linear, AIKI.
To achieve a measurement of DMin with an empty frame, you'd have to short
out the LEDs, wouldn't you? Sounds like a curious way to run a test lab. :-)
Oh, well, enough of this. We all know they exagerate.
Best regards--LRA
>From: "Austin Franklin" <darkroom@ix.netcom.com>
>Reply-To: filmscanners@halftone.co.uk
>To: <filmscanners@halftone.co.uk>
>Subject: RE: filmscanners: Nikon MF LED light source...
>Date: Wed, 18 Jul 2001 11:00:15 -0400
>
>
> > >...the problem is that the only logical reference when Dmax is quoted
>on
> > >its own is against full transparency, as you state - i.e. no
> > film, nothing
> > >in the way of the path betw the light source and the detector.
> >
> > IMHO (and I don't really want to get into this discussion *at all*), it
> > would be more honest to use blank film for this test. The difference in
> > light transmission might be miniscule, but sensitive CCDs might
> > also be able
> > to record it. Most media have a small amount of filtering properties.
>
>I don't believe film base opacity is standardized...so different films
>would
>yield different DMin.
>
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