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Re: Digital Pt/Pd tones continued

Keith, The sepia is done with Duotone and is part of my developed Photoshop
'action' and I can't tell you more than it uses two pantone inks, 158CV and
Black CV - it will be more clear when you have the action to review.  I have
tried it without, and the results are not quite as good without.  Maybe its
something like 'digital pyro'.???

I get the the Quadtone inks from WWW.missupply.com - I ordered Quad800-4
which was the initial kit for conversion of the existing cartridges.  Not a
bargain at $68.75, but it seems to work and it comes with 2oz. of each
black - 4 in all.

Nick

----- Original Message -----
From: Keith Gerling <kgerling@ameritech.net>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Tuesday, July 11, 2000 10:01 AM
Subject: RE: Digital Pt/Pd tones continued


> Thanks, Nick.  I have received inconsistent results when printing higher
> resolutions with my Epson Photo EX, as well.  I'm anxious to run some
tests.
> A couple of questions I have:
>
> 1)  Are you using the Duotone mode to apply the Sepia?  If not, how?  You
> mention you use Quadtones, so I'm confused as to what the Sepia step is
> meant to accomplish.
>
> 2)  Are you mixing your own Quadtone inks?  Who is your ink supplier?
>
> Keith
>
>
> -----Original Message-----
> From: Nick Makris [mailto:nick@mcn.org]
> Sent: Tuesday, July 11, 2000 11:12 AM
> To: Alt Photo
> Subject: Digital Pt/Pd tones continued
>
>
> Just finished running some tests with a particular image from photoshop
> v5.02 to Epson 1520 (1440dpi).  The tests included two versions of the
same
> file, one scanned at 410dpi (the most recent) and one at 360dpi - the more
> recent one and this test were done on the heels of the recent discussion
on
> tones.  Please understand that my printer is equipped with a Quadtone
inkset
> with a standard black ink and with the color inks replaced with 25%, 50% &
> 75% black inks.
>
> You may recall that I discovered, now from two sources, and previously
> reported, that the Epson 1440 dpi printers don't print images with
> resolutions greater than 360dpi as well as those at 360.  The problem
> extends from the idea that above 360dpi a certain amount of resampling is
> done by the printer, which causes results that are unpredictable.  In this
> case, all the images I printed from the 410dpi source showed some sign of
> posterization while the 360dpi source produced no signs of posteriztion,
> except as noted below.  In addition, the 410dpi file caused the print time
> to double +/-.  The resampling surely has something to do with the
printer's
> processing algorithm and the coincidental association of 1440(printer
> resolution)/4(cmyk?)=360???.
>
> Some additional observations that came from the 20 8X10 images I printed
> (most printed on satin inkjet (94 brightness) paper, but some on bond for
> comparison):
>   a.. The smoother the paper surface, less posterization and the better
the
> definition.
>   b.. The brighter the paper brightness index the cleaner the highlights.
>   c.. A simple conversion to grayscale produced posterization where the
use
> of Lab color mode did not in most cases.
>   d.. The use of color images never printed as cleanly as with Lab mode -
> remember that I'm using quadtone inks.
>   e.. The use of strictly black and white color did not produce an image
as
> clean as those produced with a slight sepia toning.
>   f.. I NEVER EXPERIENCED ANY ON SCREEN POSTERIATION WITH ANY OF THE TEST
> IMAGES.  I feel this suggests the culprit, in most posterization problems,
> is related to how the printer reacts to the input.  Can't be sure of that.
> I don't pretend to fully understand why I experienced the above, but for
> what it's worth.....
>
> I have developed/refined a Photoshop "Action" that will convert any color
> image (from a point that you think it looks best) to Lab Color, delete the
> appropriate channels, apply grayscale, a sepia tone, and convert it back
to
> RGB so that it looks like a sepia toned grayscale image.  BTW, I never
save
> my files after this conversion - it only takes a few seconds to complete.
I
> also have a Pt/Pd curve that I think works for both the Lightjet 5000 and
> the Epson 1520 with quadtone inks. I am happy to provide them to anyone
who
> asks off list.
>
> Also, as I have previously reported, no curve that I encountered during
the
> last year and half (since I started this digital project) works with the
> above.  The curve that I developed is a very straight forward (gentle 'S')
> one that only gives the appearance of added contrast to the on screen
image
> and also to the printed output.  You may be required to change it so that
> the resulting prints (negs) conform to a density and contrast compatible
> with 'YOUR' normal sensitizer.  The unsuccessful curves that I tested all
> seemed destined for output to an Imagesetter which apparently responds
> differently???
>
> BTW, all the above tests/observations were done with a positive output.
> However, I have tested the conversion to a negative and the results are
> identical.  The negative conversion is the last step before printing and
can
> be accomplished in the printer dialog box or on the Image menu.
>
> Caveat Emptor.
>
> Nick
>
>
>