Digital BW, The Print

Anthony,

> > I have all the information I need, the frequency
> > and the intensity.
>
> "The" frequency?  But for every pixel in the original scene, there are
> multiple frequencies of light, each with its own intensity.

What, precisely, does B&W film "sense"?  What "information" is recorded on
B&W film, and what information do the scanned values 0-255, let's say, give
you?  NOTHING but intensity, period.  That's it.  Light to dark.

How is this information derived from the original "scene"?  Both the film,
and the CCD, sense the number of photons that "hit" it.  They are spectral
independent.  Look at the film response curve for B&W film.  It's reasonably
flat, up to the point of fall-off.  That means that all photons, no matter
of what frequency, are treated, for all practical purposes, equally, and
generate the same results on the film, recording the average intensity of
light at "that" point in space.

Now, does the RGB data not have this "intensity" information?  How accurate
can you extract intensity from the three RGB values?  Does it matter that
different combinations of RGB produce the same intensity?  Only if that's
not how the B&W film would have seen it as well...which, is why different
colors produce the same results on B&W film...so the answer seems to be no,
it doesn't matter.

Austin