Re: Basic question about contrast and gamma

Maybe I did not make myself clear enough in my last post. What I mean
is that there is no need for such a wide variaty of paper grades in
color printing as there is in b&w because contrast can=B4t be
manipulated that much in color as in b&w. I came thinking about that
after reading another old thread so I will use the im****tant words of
the relevant post.
To adjust contrast means to make the image brighter or darker. The
only way to do that is to make the dyes thinner. This lets more light
reflect off the paper. But as a dye gets, say, thinner it removes less
of its anti-color until it finally disappears and no anti-color is
removed. And the other way around if the dye gets thicker. So the
scale doesn=B4t go from, say, a dark magenta to a light magenta but from
dark magenta to white. Or from a saturated magenta to an unsaturated
magenta.
The digital process can compensate for this unwanted increase or
decrease in saturation if contrast is adjusted in the luminosity
channel of lab-mode. In this case neither hue nor saturation is beeing
changed. There is a nice little example of that on
http://www.cambridgeincolour.com/tutorials/photoshop-curves.htm.
But
we can=B4t do the same in analog color printing.
It could well be that this is complete garbage as far as the
subtractive mixing of the analog process is concerned and if so I=B4d be
happy if someone tells me so that I can get this idea out of my head
and can think in another direction.

Best regards!
Monica Schulz