Digital BW, The Print

> From: kcongdon [mailto:kurt@...]
>
> Ok.  So, to do this, would I create a new layer containing the step
> wedge?  What blending mode would I use to blend the step wedge with
> the test image?

I think I'm starting to get what you're driving at. You want to print a test
image with various parts of it "exposed" differently, to see how they all
come out? I suppose you could do that, but remember, in digital you don't
just have one exposure time variable, you have an infinite range of
possibilities through curve adjustment. The most generally useful
"brightness" adjustment is a gamma-like curve created by dragging the
midpoint of the Curves dialog up or down, but this isn't the same as an
exposure variation in an enlarger.

If you want to try out a bunch of such curves in a single print, I suppose
you could create a number of adjustment layers, each with a different curve,
and fill each layer with "black" to disable it, except for square "white"
patches that are in different positions for each layer. You could build this
set of layers once, save it in a .psd file, and then insert various image
layers underneath the adjustment layers.

However, the kinds of tweaks you need to do to improve a particular image
usually involve specific parts of the dynamic range (e.g., darkening the
blacks or bringing out shadow detail), rather than the whole range. When I
polish a B&W image, I usually wind up appying a fairly odd-shaped curve, of
the sort that one could never get away with in a color image, and one that
is tailored to that image. So I don't think a strip that merely "exposed"
the test image by varying amounts would be that helpful.

I think the better approach is to try to improve your tools for better
screen-print matching. Then you won't have to experiment so much.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...