Digital BW, The Print

Lines in the sky?  Not with my 7000 / Piezo ProB&W.

--
Quentin

--- In DigitalBlackandWhiteThePrint@y..., "Paul Roark" 
<paul.roark@v...> wrote:
> What I'm trying to do is find a good way to see how smooth (or not) 
the
> grayscale ramps are on the various inkjet workflows.  It is, 
perhaps, a way
> to judge the extent to which the workflow can produce smooth, 
photographic
> prints.
> 
> The procedure I tried here (and would like some feedback on) was to 
run a
> Photoshop gradient at 50% opacity over and the opposite direction 
of the
> 21-step gray scale smooth ramp of the scanned test strips being 
compared.
> The purpose of this procedure is to neutralize the ramp -- except 
for those
> parts of the printed ramp that deviate from the Photoshop gradient 
ramp that
> was used to make the test file in the fist place.  What should 
stand out, I
> hypothesize, is the defects in the printing system/workflow.
> 
> To further accentuate the defects/deviations, I increased contrast 
90% and
> brightness 30%.
> 
> For comparison, I used one Piezo 1160 test strip (Piezo ink and 
driver ver.
> 5.1.3 on EAM with EAM profile) and one test strip printed with the 
3000
> using the VM-sepia ink with the neutral curve (a modified vm "warm" 
curve)
> and, of course, the Epson driver.  This print was also on EAM.
> 
> Both test strips were then scanned at the same time.  (The scanner 
has a
> defect that put 2 lines in the shadows of both test strips.  One is 
in the
> 100% patch and one in the 95% patch.  They are obvious in the image 
because
> they are the same for each test strip.)
> 
> We are, of course, familiar with the dots that the 3000 has with 
the Epson
> driver, and the dots do stand out.  So this comparison shouldn't 
even be
> close. Right?
> 
> Take a look at the scanned image.  It is in the Files section, 
which is at:
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/
> 
> Then go to > Inksets, reviews and techniques and see "Ramp-
smoothness.jpg."
> 
> (The full URL is:
> 
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/Inkse
ts%2C%
> 20reviews%20and%20techniques/Ramp-smoothness.jpg
> 
> But Yahoo mail wrecks the ability to click on wrapped URLs.)
> 
> Piezo wins the dot contest easily, but it has lots of vertical 
lines in it.
> Overall, the contest is rather closer than one would expect.
> 
> The reason I originally started making Photoshop curves to print 
Piezo inks
> with the Epson driver was to get smooth skies in some photos that 
Piezo was
> putting lines in.  I suspect the vertical lines in this test are 
what was
> causing the trouble with the Piezo outputs.  It would be 
interesting to see
> how version 6 and the 7000 Piezo software does.
> 
> Of course, I don't expect to see perfection in any ramp, and I'm 
sure most
> of the vm curves that I've done are even more defective than the 
one used
> here (which is a new one just for the VM-sepia inkset to give a 
neutral
> print).
> 
> I think this test is consistent with the comments we've heard lately
> comparing digital and darkroom prints.  I think we still have a 
ways to go.
> 
> Paul
> http://www.PaulRoark.com