From: John Campbell (tojohn@texas.net)
Date: 12/11/01-12:51:21 AM Z
Okay-deal me in: Given (1) the relationship of brightness to distance; and
given (2) the diameter of fluorescent tubes (other than the late "thin"
varieties, fashionable for kitchen cabinet applications, but not widely
respected for UV radiation); it would seem to reason that a print in direct
contact with the glass of a given set of tubes on 1/4" or greater centers
would experience (not consciously, of course) as equal a distribution of
light as one at 3" distance-or one at 30", for that matter; or 30 yards-from
the light source. The difference would be in intensity, not in distribution
of radiance. (Note, also, that the hypothetical 1/4" centers are less than
possible under the conditions of (2) above, confirming the premise.)
Hence, no banding1
N'est pas?
<<John dramatically throws down a cool million Monopoly Dollars>>
Has anyone out there actually experienced banding or stripping from UV
tubes?
If so, Judy will gladly cover my bet-while l am looking for a new tanning
salon.
(Personal aside to Sandy: please give my regards to Beth Daniels in the
English Dept. at Clemson, a fine Rhetorictician, and Very Clear Thinker.
She knows much about light and is a de-light-full human being.)
Regards to all,
John
www.photogecko.com
1- a term better suited to my Epson 3000 printer, but I won't quibble.
-----Original Message-----
From: Sandy King [mailto:sanking@clemson.edu]
Sent: Monday, December 10, 2001 10:56 PM
To: alt-photo-process-l@skyway.usask.ca
Subject: Re: UV Article
Judy Seigel wrote:
>
> > I think this is a legitimate concern. If you are using the two-tube
>> holders with 3/4" spacing between the tubes there is some point in
>> bringing the tubes closer to the contact frame where you are going to
>> get so close that banding (or stripping) will take place. I will bet,
>> for example, that if you place the contact frame at 1-2" from the
>> tubes there would be some banding on the print.
>
>
>How much is that bet? I'm finishing some tests that I will show in
>upcoming P-F, and though, as noted, I rarely bet less than a million
>dollars, I'm very soft-hearted.
>
>J.
I won't take your bet on this because I actually hope you are right.
I recently replaced my bank of 24" tubes with very close spacing
(about 1/4") with a larger bank of 48" tubes with 3/4" spacing and
have assumed up to now that it would be necessary to use the new bank
farther from the exposing plane than the old bank, which I was using
at about 2". If I can actually use the new bank at the same distance
as the old one, without banding, so much the better.
Sandy King
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