Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Austin 
Franklin" <darkroom@i...> wrote:
> Hi Anthony,
> 
> > > I do understand EXACTLY what you are saying, AND
> > > I simply disagree with it.
> >
> > So how would you reconstruct a continuous, irregular curve of 
spectral
> > energy distribution from just three data points?
> >
> > It's possible if the curve is a portion of, say, an ellipse.  But 
the real
> > world curves aren't, so you cannot reconstruct them from three
> > data points.
> > And because of this, you cannot use RGB values to reconstruct the
> > information you would need to accurate simulate the spectral
> > response of any
> > arbitrary monochrome or RGB sensor or film.  The required 
information just
> > isn't there, period.
> 
> I understand that is what you are saying, and again, I simply 
disagree.  I
> don't know what it is that is missing in yours and or my 
understanding, but
> I simply don't see that it can't be done.  I have all the 
information I
> need, the frequency and the intensity.  Both the color and B&W films
> response is deterministic to the frequency and intensity...so I 
believe I
> have the information necessary to map one to the other.  The 
converse is, of
> course, not true, you can't go from B&W to color.

I agree with Austin.   Tell us precisely what information is 
missing.  Don't speak vaguely about the "curves" because we know what 
the response curve is of the color dyes used in the film.   So we 
know exactly how much to compensate the density by for any color.   
Or put another way:  because we know the shape of the film's response 
curves there is only one unique point on the spectrum that will 
produce a given density in all three dyes.  So what's missing? 

You say that other people here understand you, but I don't see them 
jumping in to clarify what you're saying.