Digital BW, The Print

Suzanne and Martin-

I have to say that my eyes glaze over when I try to understand how to edit
the VM curves directly.  However, I have had success with an additional
paper curve, which goes just under the VM curve in the PS layer stack.

Here is my procedure.

I print a step wedge that I have made up of several of the files floating
around. It includes the piezo wedge, that has a continuous tone from black
to white and below that a 5% step with 3% and 7% above and below (and with
the 5% patches labeled for reference; and finally Tyler's Zee's.  I have
rezzed these up (nearest neighbor!) so that they print at 720  dpi at about
8 inches by 1.5 inches.  The 5% steps are easiest to read if they do not
have any border (black or white) between them- if there is good separation,
then they end up looking scalloped, because of the optical illusion.

I evaluate the wedge (after drying at least 1 hour, or with a hair dryer)
looking for areas that are compressed (i.e. little difference between the 5%
steps) and areas that are expanded (this is easiest to see in  the Zee's).
I then open a new curves layer just below the VM curves, and command click
in the steps just above and just below the problem steps, and move them up
or down with the arrow keys as needed.  I would emphasize to begin with
small changes to the curve, as this can quickly get out of hand it you
don't. Save this curve, and return.

I print the new wedge, with the name of the new curve included on a text
layer (that gets edited with each iteration), on the same sheet of paper,
just below the first curve.  That way, as I keep printing new curves, I can
tell over time if I'm going in the right direction.  I have found that it
takes at least 10 iterations to get it to where I'm satisfied.

Hope this helps- 

Bill Morse
PhotoProspect
Cambridge, MA 02139

on 2/19/02 2:49 PM, Martin Wesley wrote:

Suzanne,

You will probably need to hand edit Paul's RGB separation curves
individually to match this paper. Paul has posted some guidelines on working
with these curves and you can find them in the Files section of the group
homepage.

Martin

----- Original Message -----
From: "staetzsch" <st@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Tuesday, February 19, 2002 11:20 AM
Subject: [Digital BW] transfer function?


> I just got some cranes museo and printed out paul's new 21step wedge
> on
> a 1280, mis vm, warm curve. The 70% looks funky, sort of mottled and
> there is a distinct jump from 70% to 75% and 75% and 80% are almost
> identical. Can someone suggest how I would make this smoother? I've
> tried fiddling with the transfer function but i'm not getting good
> results.
> thanks in advance,
> suzanne



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