Digital BW, The Print

Paul,

I took CMYK density readings of the wedges I printed with the Selenium
PiezoTone ink on EAM and Photo Rag, Warm Neutral PiezoTone, MIS-FS Neutral
and MIS-FS Standard and compared them to your silver fiber print in a pdf
file you can find in the Files section in folder:

Files > Ink Sets > PiezoTones > performance comparisons > PiezoTones gray
scales

I matched up the silver print density to the inkjet densities based on the
closest visual density. What I see is that the CMY densities are all pretty
close at any given visual or overall density. The Selenium PiezoTone  seems
to track the silver print CMY distribution reasonably well. However, I
suspect that we are operating at the limit of our spectrophotometers. (Paul
has an X-Rite Digital Swatchbook and I have a Spectrocam). What we really
need are spectrophotometers accurate to 3 or 4 decimal places. Either that
or we need to compare the full spectrum values which is not an easy task.
Looking at the spectrums from 380 nm to 750nm of each reading as I took
them, I could see the shifts in color balance more clearly than just from
the CMYK values. This close to the neutral point our eyes are probably more
sensitive to minute differences than our instruments.

I also suspect that what we see as the hue of the print is mostly a result
of the what we see in the mid and high tones rather than the deep grays.

I don't know if this throws any light on the subject, but it was an
interesting exercise.

Martin Wesley

http://www.borderless-photos.de/guests.html



----- Original Message -----
From: "Paul Roark" <paul.roark@...>
To: "DigitalB&WPrint" <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Wednesday, July 17, 2002 1:57 PM
Subject: Re: [Digital BW] Selenium beta


> Robert Morrison wrote, in part:
>
> >... On EAM I would say that my general
> >impression is that FS-N looks blue and Selenium
> >Piezotones look ever so slightly eggplant.
>
> There appears to be a substantial variance in the tones that are achieved
by
> toning silver prints with selenium -- the paper, strength of toner and
time
> in toner being the primary variables.  In recent years I have (or had)
been
> using Kodak Polymax Fine Art paper and toning in selenium 1:19 for 3
> minutes.  This light toning was the usual practice, as far as I could
tell,
> for those who wanted better archival properties, a slight increase in
Dmax,
> and not a severe color change.  (Heavy selenium toning often results is a
> rather magenta print.)
>
> Using the X-Rite spectrophotometer to read a sample of a silver print that
> was toned in selenium per this normal procedure, I get the following:
>
> Dark black (not Dmax):   c=1.70, m=1.71, y=1.66, v (visual)=1.71
>
> Shadow tone (about 75%): c=0.99, m=1.00, y=0.99, v=1.00
>
> Midtone (about 50%):     c=0.59, m=0.60, y=0.59, v=0.60
>
> Light tone (about 25%):  c=0.33, m=0.33, y=0.32, v=0.30
>
> So, basically, the light tones are slightly cool, the midtones are neutral
> with a slight magenta cast (the slight "eggplant" tone, I would assume),
and
> the deep shadows/near black tones are cool.
>
> It would be interesting to see how the new PiezoTone selenium values look
in
> comparison to these.
>
> For comparison, an FS-N test strip on EAM, with the Piezo driver gives:
>
> 100% black: c=1.59, m=1.60, y=1.61, v=1.59
>
> 75%:        c=1.00, m=1.00, y=0.98, v=1.00
>
> 50%:        c=0.66, m=0.65, y=0.63, v=0.66
>
> 25%:        c=0.32, m=0.32, y=0.31, v=0.32
>
> Paul
> http://www.PaulRoark.com
>
>
>
>
> Please visit the Group Homepage to check the Files, Bookmarks, Polls and
other resources as they are often being updated. The page is at:
>
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
>
> Please follow these basic guidelines:
> - Include your full name with your message.
> - Include the address of your website, if you have one.
> - As threads develop, trim off excess portions of earlier messages to keep
them short.
> - As the topic of a thread changes remember to change the subject header.
> - Good manners are required at all time. No personal attacks or
"flames."
> - Complete your Yahoo profile.
> - Before posting a question, search the message archives and the various
resources on the homepage.
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>