From: Sandy King (sanking@clemson.edu)
Date: 04/23/03-08:40:02 AM Z
Henry wrote:
>
>How do people modify the negative on screen to produce a suitable range,
>before printing via the transfer function? Once the original image looks
>right on the screen, do most people just use the "levels" dialogue to cut
>down the output range, say from 50-200 instead of 0-255? Or do you do it by
>eye, or some other way?
>
I am not familiar with the transfer function method you mention but
there are several ways to adjust contrast in the output. Adjustment
of the levels is certainly one way to do so and this can be done
either before or after you load a curve.
Another consideration is the color of the pigment (or ink) used to
make the negative. I have found in measuring densities from negatives
printed with the Epson 2000P pigments that some colors have much
greater effective printing density than others, even though visually
there does not appear to be a very big difference. For example, I
recently measured the difference in printing density for two
negatives printed from the same grayscale file on OHP with the Epson
2000P. One was made with the Epson in color mode and the other was
made using just the black ink. The two negatives to my eyes look very
similar, the only difference being that the one printed in color mode
has a slight bluish tint and the one made with just the black ink is
neutral/brown in color. They appear,however, to have about the same
density range. However, reading with a densitometer tells a different
story, as below.
Densitometer Reading (Visual Mode)
Dmax Dmin
Color Mode 1.34 0.06
Black Ink 1.78 0.06
Densitometer Reading (UV Mode)
Dmax Dmin
Color Mode 1.99 0.18
Black Ink 2.55 0.18
The effective printing contrast is very close to what is read with
the densitometer in UV mode, and this is very different from the
Visual reading as you can see. In my case the density range from the
color mode, about 1.8, is almost ideal for printing kallitype and
carbon negatives. And I feel fairly certain that one could adjust
the color of the pigment to cover a wide range of negative density
ranges.
Again, my method for making digital negatives is very simple.
1. Get the image into Photoshop, either from a digital camera or from
a scan of a negative or transparency.
2. Work on it in Photoshop until it looks perfect on the screen.
3. Load one of the platinum curves from the CD in Dan Burkholder's book.
4. Invert the file.
5. Print on the Epson 2000P in Color Mode on OHP, but with the media
set to glossy paper to fool the printer into giving the finest weave
possible, which it will not do if you set the media to OHP.
6. Allow the negatives to dry for at least an hour before printing.
Sandy King
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