Tom
Thanks for your response. I should have been more precise in my
description of the test file that I used. I am using the bwtest file
from North Lights images, which is in a gray gamma 2.2 space. I
converted it to the QTR-Gray Photo space and saved as a tiff prior to
printing, based upon Roy's Windows XP recommendation in the
gray-readme.doc.
I also printed out the 21 step wedge, read the step densities,
recorded them in a tab delimited file and used the QTR-Create-ICC tool
found in the eye-one folder to create a new ICC profile. I then took
the original bwtest file, in gray gamma 2.2 space, converted it to
this new ICC profile space, saved as a tiff and printed in QTR. I also
reprinted the 21 step wedge, also after converting it to the new ICC
profile. The results were interesting. The bwtest file still didn't
show enough deep shadow detail. But when I measured the new ICC
profiled 21 step wedge print, plotted the L values, there is a
definite improvement in the linearity. Plotted on a graph the new ICC
profile converted 21 step wedge shows almost a straight line compared
to a slightly bowed line when the Gray Photo space was used. By
straight, I mean that the plot points touch either directly on or the
bottom or top edge of a straight line.
The improvement I am looking for is very subtle. I can still see
slightly more deep shadow detail on my monitor than in the new print.
Perhaps there is something wrong in my procedure. My display is
calibrated and profiled. Maybe I should use the 51 step scale. I
wonder if the QTR-Create-ICC tool will work with 51 steps. The sample
files are set up with 21 steps.
Appreciate any thoughts you or other forum members might have. Thanks
for making the Ilford Pearl curve available.
Ken
--- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@...> wrote:
>
> Hi
>
> I think your problem might originate from your test
file/methodology. The
> Northlight step wedge I found at their website was test-ramp.tif. If
that's
> the file you used, you will note that it is an RGB file. To my eye, the
> shadows in that image look compressed to start with. That said,
since test
> file is (supposedly) ready for printing, you should not "Convert" it to
> QTR-Gray- Photo Paper profile. You should either print it as is or
"Assign"
> the QTR-Gray Photo Paper. That will change its appearance on the
monitor,
> but not the data. Actually, you can't assign the QTR-Gray-Photo paper
> because the file is RGB, but you can assign the QTR-RGB-Photo Paper
profile
> and convert to QTR-Gray Photo Paper.
>
> You might want to read Roy's notes in gray-readme.doc in the
QuadtoneRIP\ICC
> folder.
>
> In response to the remainder of your question, to adjust the
appearance of
> your prints you can:
> 1. use the quick but ad-hoc approach of modifying the Shadow and Gamma
> sliders in QTR before printing.
> 2. Since you can measure L*, you could modify the curves and
re-linearize
> using the Curve Creation tools.
> 3. Finally you can print a step wedge (I suggest Roy's 21step or 51step
> files) and use the QTR-Create-ICC tool to create an ICC profile for your
> curve/printer/ink/paper combination and use that to preview your
image in
> PS.
>
> Tom Moore
>
> > -----Original Message-----
> > From: QuadtoneRIP@yahoogroups.com
[mailto:QuadtoneRIP@yahoogroups.com] On
Show quoted textHide quoted text
> > Behalf Of prof_mgt551
> > Sent: Thursday, May 25, 2006 10:32 PM
> > To: QuadtoneRIP@yahoogroups.com
> > Subject: [QuadtoneRIP] How to adjust Ilford Pearl Curve?
> >
> > I just started using QTR with an Epson 2200. I downloaded and
> > installed the UCpk-IlfordSmoothPearl curves that Tom has so generously
> > provided. I made a test print using the Northlight Images standard
> > test file that I first converted in Photoshop to the QTR-Gray Photo
> > Paper space (using the icc file located in the QuadToneRip ICC
> > folder). I am using the Photo black ink and a Windows XP machine.
> >
> > QTR Settings: 80 cool 20 warm, ink adj 0, gamma adj 0
> > The print overall looks good except the deep shadows start losing
> > detail. Step 100 measures L 5.40, step 95 measures only L 6.34. From
> > step 90 and on, the L value measures much more separation between each
> > step and you can clearly see the steps.
> >
> > What options are there for opening up the deep shadow between step 100
> > and step 95. The rest of the gray scale looks pretty good and the
> > tonality is close to what I see when viewing in Photoshop. I don't
> > want to adjust the ink level since solid black is nice and deep. I
> > don't want to use the gamma slider and open up the shadow at the
> > expense of the mid-tone.
> >
> > Are there any other tools in QTR that could be used to make this
> > adjustment or modify the curve?
> >
> > Thanks for your help.
> >
> ...
>