Digital BW, The Print

Anthony,

> > ... it is therefore quite deterministic to
> > produce a mapping from the information on the
> > color film, as produced by it's spectral response,
> > to the same spectral response that B&W film does.
>
> Absolutely ... but this presumes that you have the original complete
> spectrum to work from, not just RGB values.

Once again, RGB values from a CCD imaging device encompass the entire
spectral range that Tri-X encompasses, and therefore you DO have the
original complete spectrum to work from, with the "original" spectrum being
defined as the spectrum that Tri-X can record.  Good grief.

> Once the color film has
> converted this broad spectral response to three RGB values, a
> conversion to
> B&W based on this correlation between curves is no longer possible.

And, as I've said, is simply wrong.  You somehow believe that the spectrum
that RGB represents is smaller than the spectrum that Tri-X responds to, and
that is your mistake.

What you are confusing is the limiting of spectrum by differing color
spaces, and in the case of Tri-X, you will find it has a very limited
spectral response, and therefore RGB will encompass it and do exactly what
you claim it won't, reproduce it in it's entirety.

Austin