From: Judy Seigel (jseigel@panix.com)
Date: 11/11/01-11:32:58 PM Z
On Sat, 10 Nov 2001, Ed Stander wrote:
> The neat thing came when I replaced the L-1250 with the L-1252 wide
> spectrum bulb, again used at 1000 watts. This bulb pegged my poor UV
> meter at 6000 microwatts/square cm. Further, an exposure time to four
> minutes gave a result identical to the L-1250 at 20 minutes (ie: 8
> distinct steps commensing from max blue at step 2). This suggests that I
> should be able to make a cyanotype in 30 seconds with the system running at
> full brightness. Pretty neat.
So OK, here's the damp blanket department: who pays for your electricity?
You propose 5000 watts for 30 seconds.... UV fluorescents use a total of
160 watts for eight 24" bulbs, and expose, with fresh emulsion, in approx.
3 minutes. That would be 480 watt minutes vs. 2,500 (if my math is right).
My fluorescents give even light over 22 by 23 inches -- with the strips
touching each other. My tests show they can be ranged over a larger area
without much loss of speed.
I assume electricity costs more here than anywhere else in the galaxy,
maybe you even live by a waterfall that electrifies you for free. But
there would also be unwelcome heat from those 5000 watts in summer (unless
you could hook it up to make coffee?). Plus, how much heat is deployed to
the picture plane? Does the apparatus have a fan??
Maybe heat for 30 seconds wouldn't affect the emulsion, but my tests
showed (Post-Factory #5, page 31, bottom sample) that a slug of heat
before and/or after exposure definitely upped cyano highlights. It might
not in such a brief hit, but I wouldn't assume it without testing.
Judy
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