Digital BW, The Print

----- Original Message ----- 
From: "Austin Franklin" <darkroom@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Wednesday, May 21, 2003 12:10 PM
Subject: RE: [Digital BW] Digital, film, scanning comparisons


> Martin,
>
> > A drum scanner will give you a "monochrome" scan.
>
> Er, how?  I don't know of any, but perhaps there are, that have a ND
filter
> channel.  PMT scanners use filters just like CCD scanners, it's just that
> they use a beam splitter to separate out the channels, and they all three
> read from the same beam.

That's why I put the "monochrome" quotes. That does raise a question in my
mind though. With the drum scanners where in the light path are the color
filters? Are they between the PMT and the film or between the light sources
and the film? If the latter case, I would assume there is a theoretical
advantage in resolution to using a single color light source. If filtration
is after the light passes through the film than all three channels would be
equal.

Martin