Re: update: screw-in BLB light-box

Thanks so much, Sandy, for the calculations. I have copied the group on my reply (and I think your original message will tag along) as a couple of other alt photo folks expressed interest in the screw-in bulbs box.

Best,
Judy

--
Judy Rowe Taylor
Mukilteo, WA
Art is a voice of the heart, a song of the soul.
www.enduringibis.com
jude.taylor@comcast.net or judyrowetaylor@enduringibis.com
> Hi Judy,
> 
> I calculated that you could place the 20 watt screw-in tubes on 1.5" 
> or 2" center and that they would in fact produce more radiation, and 
> faster printing times than the regular tubes. I can certainly 
> understand why printing times were so slow if you placed them on 6" 
> center.
> 
> Best,
> 
> Sandy
> 
> 
> 
> 
> 
> >Hi Sandy,
> >
> >The screw-in bulbs were spaced 6" from center to center all around 
> >(two rows of three bulbs for a total of 6 bulbs) because that is how 
> >the ready-made bathroom lighting fixtures were arranged; conceivably 
> >they could be placed closer together.  I am not at home where I can 
> >check right now, but I expect they could go 1 to 1.5 inches closer 
> >together as long as air can circulate around the ceramic sockets - I 
> >expect this would be needed.
> >
> >If the 20 watters would cut the time from 20 minutes to 10 minutes, 
> >then the cost is definitely worth it!  Many thanks.  Judy
> >--
> >Judy Rowe Taylor
> >Mukilteo, WA
> >Art is a voice of the heart, a song of the soul.
> >www.enduringibis.com
> >jude.taylor@comcast.net or judyrowetaylor@enduringibis.com
> >
> >
> >>  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