Digital BW, The Print

Got it.  Antonis and I are using his spectrophotometer to read the 21 step
wedges.  I have previously reported the dmax for the 100% black.  We have
full spectrum information but haven't figured out how best to communicate
the information.  Just looked at the your scan that martin posted.  Do you
have a fade of a more neutral MIS sample.  The one that I see is very warm
to even the piezo.  My guess is that as you tone the MIS blue that you will
bet much poorer fade results...but that is just a guess.

Robert

On 9/12/01 6:09 PM, "Paul Roark" <paul.roark@...> wrote:

> Robert wrote:
> 
>> Paul, are your figures % of dmax?  Or did you correct for the log scale?
>> Just trying to figure out how they correspond to mine changes.
> 
> I use a scanner to measure the differences, scanning the test strip along
> with the control strip.  I then use the Photoshop Histogram tool to measure
> luminance and RGB values.  When I look at fading, all I'm doing is taking
> the percentage of fade (lightening) of the selected area (for example the
> 50% patch of the 21-step test file print) relative to the starting
> luminance/brightness of the particular patch.
> 
> Paul
> 
> 
> On 9/12/01 8:53 AM, "Paul Roark" <paul.roark@...> wrote:
> 
>> Mike,
>> 
>> You asked:
>> 
>>> Has anyone else measured the actually loss in density of Piezo prints?
>> 
>> I ran a comparison fade test in my florescent light tester with MIS
>> (standard quads) and Piezo inks.  Both were on Epson Archival Matte, and
>> both were in the fader at the same time, so other possible variables were
>> kept to a minimum.  After 300 hours the MIS 50% patch had lost 4.6%
> density.
>> The Piezo test strip had lost 7.6% in the 50% patch. (The two blacks had
>> both faded 15%, but because of the intensity of the light, the black would
>> absorb more and heat up more.  So, I think the test conditions exaggerate
>> the relative fading of the dark tones.)
>> 
>> For most parameters I'm looking at, by 300 hours in my fader the rate of
>> change has slowed considerably.  So, while these prints may never totally
>> stabilize, I think at the 300 hour point we can see what the prints will
>> look like after the prints have "warmed" completely.
>> 
>> While the Piezo faded 65% more than MIS, neither had really faded that
>> dramatically.  I continue to agree with the consensus of south-window
>> testers that color shifting is more significant than fading.  I'll send
> the
>> scans of the test strips and control strips to Martin to put in the files
>> section of the forum.  (See Fade-MIS-Pzo-300Hr.jpg)
>> 
>> I would be curious if the scanned images look like what south-window
> testers
>> see, and how long it takes for south-window prints to take on this color.
>> 
>> EAM is the champ when it comes to fade resistance among the paper I've
>> tested.  I don't know what paper was being used below, but the alleged 2
>> stop fading in 60 days seems extreme.  I would guess there are some
> factors,
>> perhaps including display conditions, that we don't know about.
>> 
>> Paul
>> http://www.PaulRoark.com
>> 
>> ______________________________________________
>> 
>> 
>> -----Original Message-----
>> From: Michael J. Kravit [mailto:kravit@...]
>> Sent: Wednesday, September 12, 2001 5:16 AM
>> To: DigitalBlackandWhiteThePrint@yahoogroups.com
>> Subject: [Digital BW] Piezo - Loss of Density
>> 
>> 
>> Last eveing I was speaking with another photographer by telepone. He
>> told me that in California Huntington Witheral is ready to give up on
>> Piezo because his display prints are losing 2 stops of density after
>> just 60 days on display.
>> 
>> Supposedly he has spoken with Jon Cone and Cone told him it was his
>> paper. So he has tried numerous papers and has not been able to keep
>> the prints from losing density (fading).
>> 
>> Has anyone else measured the actualy loss in density of Piezo prints?
>> 
>> MIke
> 
> 
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----------------------
Robert Morrison
rmorrison@...

310-397-2704

4131 Bledsoe Ave.
Los Angeles, CA 90066