Sodium Vapor Darkroom Lights

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I have decided that I want a sodium vapor darkroom light. There are two brands that I am aware of. Osram makes one called a DUKA which is quite small and will fit on the shelf. I don't think that this will serve my purpose. The other is Thomas which will work. However, their Duples Super Safelight is not recommended for darkrooms smaller than 10x12. My darkroom is 7x12. I would appreciate some comments on this. Does anyone use a Thomas in a darkroom close to the size of mine and, if so, what are your experiences?

Thanks for your input.

Bob

-- Robert Bedwell (rlb@triad.rr.com), April 27, 2000

Answers

Last year while I was bui8lding my new house, I rented a darkroom about the same size as yours equipped with the big Thomas light. I experienced extreme fogging (I watched the image come up and then watched it go completely black)with Oriental VC paper. I had to get a small red light from the darkroom manager to complete my printing session. He called me later and confirmed that the thomas was fogging paper.

Based on that experience, I did not purchase a new safe light for my new darkroom, but contine to use the $10 red safelight I picked up used about 10 years ago. The Thomas has too much output for a small darkroom.

-- Gene Crumpler (nikonguy@worldnet.att.net), April 27, 2000.


I have to second Gene's findings....in college we had Thomas' hanging in classroom-sized (roughly 20'x30') darkrooms and we had to make sure we had the doors at the lowest setting...even then most students strayed to the far side of the room to print. I've found that the delta safelight bulb for a standard socket is a very fine and very safe source for my small darkroom (10'x12'). I've installed it in a old SV flood with stand and bounce it off the ceiling when the paper is out of the safe then point it down for inspecting tests. It passed the twenty minute safelight test with flying colors. Nice, cheap alternative for folks without Bedwell's kind of cash.

-- Trib (linhof6@hotmail.com), April 27, 2000.

Over the years I have managed to acquire six small safelights for my 8x10 foot darkroom. I have placed them in key spots, like over the trays and the paper cutter. The ones over the enlargers are wired to the timers so they turn off when I make my exposures. I use 15 watt bulbs in the ones near the ceiling--the ones mounted lower get 7.5 watt bulbs. I've never had any problems with fogging, and they were CHEAP at garage sales.

-- (edbuffaloe@unblinkingeye.com), April 27, 2000.

I bought a Thomas and did fogging tests.

I checked various papers with the vanes wide open and then fully closed.

With modern VC papers, I experienced fogging on Oriental VC Plus and Forte Polygrade even with the vanes fully closed. Other papers were generally OK with the vanes fully closed. None were safe with the vanes fully open.

I bought a Premier 10 x 12 safelight with Red filter to handle the VC papers.

My darkroom is similar in size to yours. If I were doing it again, I would not buy the Thomas. I would probably go with 4 Premier units: 2 red and 2 amber.

One thing that surprises me is that if I use the red and Thomas together, I get quite good color vision.

I want to try is making my own LED safelights. LEDs are cheap, and I have a good powersupply for them. I'm planning on alternating rows of amber and red LEDs and being able to switch them independently.

-- Charlie Strack (charlie_strack@sti.com), April 28, 2000.


I have about the same size darkroom as you and I have been using a very old Thomas safelight for about a year. using kodak paper and Ilford . I havn't had any trouble with it

-- Frank Miller (fmiller@cilco.com), May 08, 2000.


I've also used the Thomas safelights for years. However, I noticed that I was starting to get fogging and after exhaustive testing decided to take the light down and actually look at it. To my suprise the gel filter (sandwiched between glass) which covers the sodium lamp had badly deteriorated and was leaking light like a sieve. Maybe this will save some of you Thomas owners some time.

-- Bill Snow (wesnow@southernco.com), June 22, 2000.

I should have mentioned in my earlier post, that I used an extended time under the safelight, probably up to 5 minutes, to cover full development.

-- Charlie Strack (charlie_strack@sti.com), June 22, 2000.

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