RE: AmerGraph ULF-28

Sandy,
It is not clear to me from your explanation what is the nature of the
radiation. Is it a continuous specturm radiation like the sun or is it a
spiked spectrum like mecury vapor? As I look at the data that you provided I
can get a pretty good idea of expected exposures. My typical palladium
exposure is about 4 minutes. Exposure for gum is about 1 minute. I have a
bak of BL lights. That would be very consistent with your exposure data.
ANy idea of how long would the CWX bulb last?
Marek

>From: Sandy King <sanking@clemson.edu>
>Reply-To: alt-photo-process-l@usask.ca
>To: alt-photo-process-l@usask.ca
>Subject: RE: AmerGraph ULF-28
>Date: Fri, 02 Jun 2006 10:00:56 -0400
>
>
>Marek,
>
>It is a kind of HID lamp, like the metal halide, but there are some
>significant advantages. Unlike metal halide lamps, which may take several
>minutes to reach full radiation, CWX gives full output almost immediately.
>And, the lamp will strike immediately after shut-down, unlike MH lamps,
>which usually must cool down before they will re-strike.
>
>The SPD curve of varies according to Dose, as you have the choice of
>Gallium, Mercury, Iron, Thallium, Lead, or Indium, all with radiation
>spikes at different points on the SPD chart. I have been working with the
>Mercury Dos, which is fairly similar to the SPD of BL tubes, with a major
>spike at 365 nm, but also has a spike almost as high at 435 nm which is
>responsible I believe for the very high printing speed of the ULF-28.
>
>People who know palladium printing should be able to look at the data I
>provided and get a reasonably good idea of the printing speed of this unit
>compared to their own. The ULF-28 is without question the fastest printing
>light I have ever used, and I have tested a number of different light
>sources, including a number of HID lamps, the NuArc 261k and 261ks, as well
>as fluorescent banks using AQUA, BL, BLB, and SA tubes.
>
>Sandy
>
>
>
>
>>Sandy,
>>What is a continuous wave xenon? And congrats on your new full time job
>>(photography?)
>>
>>Marek, Houston
>>
>>>From: Sandy King <sanking@clemson.edu>
>>>Reply-To: alt-photo-process-l@usask.ca
>>>To: alt-photo-process-l@usask.ca
>>>Subject: AmerGraph ULF-28
>>>Date: Thu, 01 Jun 2006 15:27:52 -0400
>>>
>>>
>>>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 06/02/06-09:22:42 AM Z