From: Sandy King (sanking@CLEMSON.EDU)
Date: 04/15/02-09:32:36 AM Z
The Philips tube John makes reference to is the Super Actinic 03
tube. I found it in 24" and 36" at
http://www.marineandreef.com/shoppro/phillips-fluor-lamps.html with
just a brief web search. I suspect you can find it in 48" with just a
bit more searching.
The Philips Super Actinic 03 tube is a good tube for printing in
platinum and kallitype but for any of the other processes the BL
tube, either Philips, GE or Sylvania, is in my opinion a better
choice. This opinion is based on numerous controlled testing of a
step wedge with several different processes and light sources. You
can see some of the results of this testing in my article on UV
printing at http://unblinkingeye.com/
One addendum. I did not originally test Pt/Pd for the article.
However, some weeks ago Dick Arentz got in touch with me and after
some discussions we agreed to collaborate and run some tests with
Pt/Pd. similar to the ones I did with gum, vandyke, kallitype,
cyanotype and carbon. We just got around to completing those tests.
Dick coated two sheets of 11X14 paper using his Pt/Pd Mixture #7,
then cut the paper into 4X5" pieces and overnighted it to me by
FedEx on Saturday. I ran the tests yesterday, developing in 25%
Potassium Oxalate and clearing for 10 minutes in EDTA. All of the
tests have at least two steps of maximum black and all cleared well.
Tests included five different 24" fluorescent tubes, all powered with
an Icecap 430 ballast. Since this ballast is rated VHO and is
electronic its power could not be a limiting factor in light output.
The same step wedge was used for all tests, and all exposures were
made for ten minutes in the same contact printing frame placed at 4"
from the light source. The tubes included:
1. Philips Super Actinic 03 tube, 20 watts
2. URI Super Actinic VHO tube, 75 watts
3. GE BLB, 20 watts
4. Sylvania BL, 20 watts
5. Philips BL, 20 watts
I also tested my HID Mercury Vapor lamp, at 20" from the pod of the
lamp to the printing frame, in two configurations. Exposures were
also for 10 minutes, after the lamp reached full output.
1. HID Mercury Vapor Lamp, 1000 watts, with center filter
2. HID Mercury Vapor Lamp, 1000 watts, without center filter
Some of these tests will be sent to Ed Buffaloe for inclusion in the
article. However, my preliminary observations, which are based on
considerations of printing speed and contrast alone, are:
1. There was virtually no difference in printing speed between the
regular output and VHO Super Actinic tubes.
2. Printing speed of the BL and Super Actinic tubes were virtually identical.
3. When used without a center filter the printing speed of the HID
Mercury Vapor lamp was at least two full stops faster than either the
BL or SA tubes. When used with the center filter the BL and SA tubes
printed slightly faster.
I may have more to say after plotting and looking at the curves.
Sandy King
>John Campbell wrote:
>>
>> Keith,
>>
>> If you are building a new array from scratch, why not use 48" fixtures and
>> 40-watt tubes? I recommend Phillips product number 046677-30108-5, which is
>> a super actinic radiation source available in 48-inch lengths. I don't
>> think you'll have any problem with lengthy exposure times!
>>
>
>
>John,
>
>I've searched all over the web for this bulb and can't find it. Would
>you happen to know where it can be found?
>
>Many thanks,
>
>Bill
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