Re: update: screw-in BLB light-box

Hi Sandy,
I had read the experiment on the Blinking Eye comparing the various light
sources..... I wonder why the printing time is almost the same with a bank
BL bulbs as with a high output light.?

      I have several Olec Mercury Vapor combination units that I had
planned to use............ The output on each of them is a variable 1000
watts, 3000 watts, and 5000 watts....... I am trying to get great relief
in my gelatin images and I bought these lights thinking the high output
would offer more penetration much faster.................. Any thoughts on
this?

----- Original Message -----
From: "Sandy King" <sanking@clemson.edu>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Monday, August 01, 2005 2:09 PM
Subject: Re: update: screw-in BLB light-box

> Hi Judy,
>
> Thanks for the update. Were the screw-in tubes your unit placed as
> close together as possible? This be taken into consideration in
> weighing the pros and cons of the screw-in versus regular tubes.
>
> The use of 20 watt screw-in tubes in place of 13 watt ones should
> reduce your exposure by about 1/2, but if your tubes are already
> placed together as closely as possible that still would not reduce
> your exposure times to what you observed with the Edwards unit.
>
> Sandy
>
>
>
>
>
> >Hello Sandy King (who first posted a query about the screw-in BLBs
> >as a possible source of UV for alt processes) and anyone else
> >interested in knowing how they worked.....
> >
> >This past weekend, during an excellent workshop on PT/PD printing
> >taught by Kerik Kouklis at the Cascades Academy of Photography,
> >which is located in lovely "old town" Issaquah, Washington, I was
> >able to compare printing times in my lightbox (6 screw-in 13 watt
> >BLBs with the print frame 4" from Light source) with one of Edwards
> >Engineering fluorescent tube boxes. Needless to say, the times were
> >longer - a tad more than 10x - but the results were the same.
> >
> >Stated specifically: A digineg created with Keith Schreiber's
> >method (looks orange on screen but prints yellow-green) and printed
> >on Pictorico OHP using an Epson 1280 (dye inks) with 100% PD soln.
> >on Cranes "Platinotype" (B&S name for this paper) required 1 min 50
> >sec in the EE box, where as the same required 20 min in my box. All
> >other factors were more-or-less (read "unscientifically determined
> >to be" ) equal.
> >
> >For the time being, as I perfect coating techniques, etc., I am not
> >bothered by the excessive time - gives me an opportunity to make
> >notes which I tend to forget to do when I am working at a faster
> >pace - but will most likely give the 20 watt bulbs a try before
> >building a larger tube box.
> >
> >Anyone know right off the top of their head if I might expect
> >exposure vs wattage to be linear in this situation (i.e., will the
> >increase from 13 watts to 20 watts cut my time by about one-third)?
> >If not, I will go back to some of the published data /
> >manufacturer's data to search out the answer to this question. If
> >it is less than linear, I probably wont bother with the more
> >expensive screw-in bulbs, but just go right to a tube box sometime
> >in the future.
> >
> >Thanks!
> >Judy
> >
> >--
> >Judy Rowe Taylor
> >Mukilteo, WA
>
>
>
> _____________________________________________________
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Received on Fri Aug 5 12:11:21 2005