[filmscanners] RE: Scanner Profiling

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

Doug writes ...

> On Tue, 15 Jul 2003 13:17:58 -0400, HMSDOC wrote:
>
> > [...] making the scan and profile once you have the IT-8 target
> > and data file. [...]
>
> As long as you're scanning positives (slides) this will work.  So far,
> I haven't heard of IT-8 targets on negative film.  And you'd need a
> target for each different type of negative film you use.

  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.
That is ... all the IT8 need be is (1) and accurate representation of the
ref file, and (2) is representative of as much of any gamut any film would
present to the scanner (i.e., pick the most color-rich chrome).  Now you
have a profile which yields accurate RGB data for absolute colors, all with
respect to a convertible profile.  Negative film does not present a gamut
that is different than a chrome ... it only needs additional operations,
mask subtraction and reversal ... neither of which needs anything other than
accurate RGB values for the absolute colors.

  It could be argued the gamut of negative film is different because it is
reversed ... but you'd also need argue that it presents colors (to a
scanner) not capable of positive film.  Is that what you're saying?

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


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