In fact, with Photoshop it is easy to make a negative with different
colors, and intensity of color, throughout the image. To the extent color
affects contrast, it would seem there is infinite control possible. I know
in conventional silver printing, the stain has a great effect. The pyro
negs are easy to print on VC paper with split filtering, since the stain
acts as a low contrast filter itself. I remember an article in one of the
photo mags a few years back. The author described a method of contrast
control (this was old-time printing with an enlarger) for VC papers with a
mask, consisting of a clear negative painted on with different colors to
alter contrast.
May be something to fool around with.
By the way, let me recommend an excellent Photoshop book: Photoshop 4
Artistry, by Barry Haynes and Wendy Crumpler (info at newriders.com). This
book is directed to photographers, and contains a lot of ideas I have not
seen elsewhere. It comes with a CD so you can recreate the procedures in
the book.
--Ken Carney
Regards,
--Ken Carney