Thanks, Sandy- hope the eye surgery goes well!
Happy retirement!!!!!
Susan
----- Original Message -----
From: "Sandy King" <sanking@clemson.edu>
To: <alt-photo-process-l@usask.ca>
Sent: Thursday, June 01, 2006 12:27 PM
Subject: AmerGraph ULF-28
This is a brief update on my experience with the
Amer-Graph ULF-28 printing unit. For those who
may not have seen my first message about this
unit, it is a Continuos Wave Xenon plate maker,
similar in size and configuration to the NuArc
261k and 261ks. This is a prototype unit which
was sent to me by Amer-Graph for testing purposes.
Over the past several weeks I have tested the
ULF-28 with several printing processes, including
palladium, cyanotype, palladium and carbon,
comparing the results with my bank of BL
fluorescent tubes. Papers used were Stonhenge and
COT 320. With every process, when using the same
paper, the ULF-28 prints a full 1.5 stops faster
than the BL bank.
For example, take the following situation.
1. Pure palladium on COT 320.
2. Double Coating, using 2 ml of a 1:1 mixture of
15% palladium chloride and 25% ferric oxalate for
both coatings. Short blast with hair dryer after
both coatings to keep the solution on the surface.
3. Dry for 15 minutes, with air from fan.
4. Exposure with a Stouffer TP 4X5 step wedge
5. Development in a 25% solution of potassium
oxalate, with 2ml of a 5% solution of potassium
dichromate added per liter of developer for
contrast control.
6. Workroom at 72ºF, RH 52%.
Best exposure for the ULF-28, as judged by the
first maximum density that merges with the next
one, was 50 units, where one unit = 1.3 seconds,
for a total time of 65 seconds.
Best exposure for the BL bank, similar
evaluation, was 200 units, where one unit = .98
seconds, for total time of 196 seconds.
The ES of palladium, as processed above, was 12
steps (of log .15 each) from maximum density to
paper white, or about 1.80.
I will be doing a full review of this unit for
publication later this summer. Hoped to have it
done by now but have been delayed due to
complications from eye surgery.
Sandy
Received on 06/02/06-06:28:10 AM Z
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