Digital BW, The Print

Chris,

You wrote:

>Is this step wedge on file specifically for use with the VM inkset or
>can it be referenced for the creation of transfer functions in
>general.

These step wedges are generic.  (I didn't even know one was in the files
section; Photoshop generates them.)  I find them a very useful in writing
curves for various purposes.

By the way, the Transfer Function is great because it can be used in
addition to the Image Adjustment Curve.  However, the Image Adjustment
curves give much better control.  Be sure your graph is set to the 0-255
8-bit luminance scale (black on the left of the horizontal axis).  It give
much finer control than the 0-100% ink scale.

> Also, I notice that Jerry Nevins suggests having an online
>service create a print-out of a step wedge in order to create
>transfer functions.

An objective, accurate step wedge would be nice to calibrate the scanners'
gamma.

Many of us have the IT8 cards.  Does anyone know which black patch is right
on 50%?

> Is this step necessary?... I'd prefer ... keeping the feedback
>loop between my monitor and printer, ...

Exactly.  I tried to write the curves to be essentially linear, but your
monitor is what counts.  All I use is the Photoshop Gamma routine to set my
monitor.  Then, with the curves I've written, the combined RGB curve is
essentially free and available to use to profile your printer to monitor.
You can use the step wedge, but you might find as a first step that a very
large (I have a 999 pixel brush) area of 100% and 50% (with lots of 0% white
paper still showing), make it easier to match printer output to monitor.
Just grab the RGB curve at 50% and pull it up of down until you match the
large 50% visually to the monitor.  That actually tends to get things rather
close.

Paul