I <3 Thomas Duplex

Leigh B · Jan 4, 2012

Helinophoto said:
Where can I buy one?

Yes, the Thomas Duplex safelight is a marvelous invention.

It uses a sodium vapor lamp, so the light without filtration is monochromatic yellow, outside the sensitive range of paper.

Unfortunately it's no longer in production, but you can find them used, and replacement lamps are still available.

- Leigh

Helinophoto · Jan 4, 2012

Thank you for the tip, I will be looking out (literally) for it =)
I find it hard to follow development in the tray for example, because it's so dark. (My bathroom has black tiles on the walls).

ParkerSmithPhoto · Jan 4, 2012

Helinophoto said:
Thank you for the tip, I will be looking out (literally) for it =)
I find it hard to follow development in the tray for example, because it's so dark. (My bathroom has black tiles on the walls).

It might be overkill for a space that small, but many people report using black foam core to block out the top windows and keep the light down.

In my basement, the light is hanging a good eight feet from my developing tray. Even full closed I can see the clock on the wall and my body casts a soft shadow over the print tray. So I can see the print but it isn't getting blasted by light while it's in the tray. One it hits the fix I can open the vanes and start getting an idea of the print while it's fixing.

Have you tried just bouncing a standard 15 watt yellow safelight off the ceiling? Not sure what the green safelight is, but it sounds like it would be very dark.

Sundowner · Jan 4, 2012

I've got very little light in my area, now...I've got a small safelight that's close to the enlarger, and I have an old Kindermann Inaktin globe fixture over the sink. I've actually got a second Inaktin base, but I don't have another amber globe. Hmm...classified ad, perhaps...

I was thinking of placing the Thomas at the far corners for soft light everywhere. My walls are a cream tone...I didn't feel like painting them white. I figured that cream would work.

ParkerSmithPhoto · Jan 4, 2012

Thomas Duplex renovation

Here's a few photos of the renovation of Thomas Duplex:

1. As I bought it, you can see the filters are wasted.
2. Measure and cut the new gels
3. Soaking the glass before scrape and tape
4. The melted gelatin goo floats right off the glass
5. New filters, with Rosco #19 gel and Rolux diffusion, taped around the edges

ParkerSmithPhoto · Jan 4, 2012

More photos

Last few pics:

1. The small chain or whatever that helps support the bulb was missing so I just used a loop of uncoated picture wire
2. Tools needed for the job
3. Light warming up with gel but no diffusion. At first I thought it might be fine without the diffusion, but that bad boy could give you a suntan! You definitely need diffusion. You could add as much as you want to the inside filters to bring the light way down, and then use one layer on the vanes to do fine tuning with the pull chain.

Hope that helps.

Sundowner · Jan 4, 2012

Great pictures! Thanks for that!

nsurit · Jan 16, 2012

So it looks to me like you are using the Rosco #19 on both the top and bottom filters as opposed to a yellow of some sort. Is that corrrect?

Mark Crabtree · Jan 16, 2012

I "heart" my Thomas Duplex too! I run mine throttled way down in my mid-sized darkroom with low ceilings. I could probably open the vanes more, but it is plenty bright for me now and has been safe with every paper I've tested. At least one of mine came from a color lab and a friend uses his for color, but I haven't tried that yet. Mine is currently way to close to the paper supply on my color printer.

That is a nice renovation guide. I can't remember what I did for my color set, but I made my black and white only set with Kodalith. Cheap on eBay, but no cheaper than your solution. I found vinyl tape the exact width in a set with several appropriate colors at Lowes. Certainly not necessary, but these seem like an exact match to the original tape on mine.

EdSawyer · Jan 17, 2012

I have a spare one of these I can part with, Helinophoto. Shipping to Norway might be expensive, (I am in US). It's a great light. I just don't need 2 of them.

-Ed

Mainecoonmaniac · Jan 17, 2012

Hey thanks for the link! I got one free because the university I was working at tossed it. I've been using it for years and the replacement bulbs cost $100. The place you recommend is a 1/3 of that.

Richard Jepsen · Jan 20, 2012

Our community DR had a Thomas over our sink. While tray developing paper the safelight fell from the ceiling, hit the sink edge, and crashed to the floor. It was a near miss. Providence was with me.

Glass on vans broke but the tube works. Built like a brick. Your info on filter replacement would have been handy. There is a long post in Apug about replacing inner and outer filters and what color to use. Parts are expensive for the Thomas.

I replaced the Thomas with a 10x12 Kodak Utility light supplemented by extra safelights at stations. Not talking over the Thomas buzz is nice when instructing. The unit operated with the vanes mostly open, bouncing light off a black ceiling. No fog with OC safe papers but other papers were fog sensitive.

Leigh B · Jan 20, 2012

Thomas buzz???

There's something wrong with your light. Mine makes no noise whatsoever.

- Leigh

Steve Smith · Jan 20, 2012

Is Rosco sheet a theatre lighting gel? If so, for us in the UK, the same thing is available from Lee Filters.

http://www.leefilters.com/

Steve.

ParkerSmithPhoto · Jan 20, 2012

Steve Smith said:
Is Rosco sheet a theatre lighting gel? If so, for us in the UK, the same thing is available from Lee Filters.

http://www.leefilters.com/

Steve.

Yes, indeed. Theatre and video productions.

Newt_on_Swings · Jan 20, 2012

Leigh B said:
Thomas buzz???

There's something wrong with your light. Mine makes no noise whatsoever.

- Leigh

The buzz signifies the tube is about to go. I have it as well, but I'm going to run it until its burnt out. As the only time I notice it is when I am right by it, I have tunes to jam to in the darkroom with a under the sink ipod speaker dock which over powers the buzz.

ParkerSmithPhoto · Jan 20, 2012

nsurit said:
So it looks to me like you are using the Rosco #19 on both the top and bottom filters as opposed to a yellow of some sort. Is that corrrect?

Yes. You could configure this in many ways to get just the right type and amount of light. I moved mine about eight feet from my enlarger and dev tray, and now it bounces off a big white wall. Super soft, lots of light even all the way closed. Really love it.

By the way, if anyone is interested, I'm about to buy a whole darkroom setup from a guy, keep some stuff and sell the rest, including another Thomas Duplex, so if you are in the market, shoot me a PM. I'm sure the filters will need replacing!

Mike W · Jan 22, 2012

I tested my Duplex safelight and found that I had to close the flaps.
http://www.kodak.com/global/en/consumer/products/techInfo/k4/k4TestSafelite.shtml

smieglitz · Jan 22, 2012

We have 3 Thomas units in our college darkroom. The darkroom is about 15' x 30' and the lights are spaced about 10' apart. They are about 1' below and bouncing off the ceiling with the vanes open approximately 1/3 of the way. When I'm working in there alone I usually close the vanes because I prefer it dimmer than the students. (sic) The brightness sometimes interferes with seeing the projected image at smaller f/stops when burning/dodging.

The only other complaint I might have is that sometimes the lamp contacts get corroded and stick to the socket making the lamp hard to remove. It is awkward to begin with and if the lamp is stuck, very difficult to remove. But then I've only had that problem twice and have only replaced about 5 lamps between the 3 units in 22 years. And that's with them burning about 55 hours per week. They are a very good investment IMO.

I have experienced some fogging with ortho materials so I have a couple 10" x 12" safelights with 15w incandescents and 1A filters directly above the sink areas when I'm doing ortho and have the Thomas' shut off.

Mainecoonmaniac · Jan 22, 2012

My dumpster dived Thomas Duplex hums

Can't hear my radio it's so loud. Is there a fix?

Mark Crabtree · Jan 25, 2012

Thomas Duplex filters

Here's some info that I thought might be interesting. This may all be common knowledge, but hopefully useful to some.

The Thomas Duplex safelight was offered with various filters for different uses. Most of us at APUG are going to be interested in the versions "Type DUB" for black and white printing and ortho processing, or the "Type DUC" for color printing. To the best of my knowlege (and personal experience), the Type DUC is also fine for standard black and white printing (but not ortho film processing) .

The only differences are the filters fitted, and the information below explains the tape color codes that indicate the use for each filter.

This is excerpted, paraphrased, or interpreted from literature from Thomas Instrument Co.:

Black and White Printing (Type DUB)
Yellow filters in the housing and Red in the vanes (that refers to the color of the taped edge of the filter). Vanes can be fully open in a large darkroom (they indicate 12 x 14 feet with "standard" 9 1/2 foot ceiling height and the bottom of the safelight 7 feet high). Being able to use the vanes fully opened would obviously depend on how close the installed safelight is to areas where paper is handled. The vanes should be closed as much as necessary to prevent fogging for the exact darkroom size and conditions.

Ortho Processing (Type DUB)
"For Ortho Films, papers and most graphic arts materials, the vanes should be fully closed so that the light passes through the yellow and red filters. If the light level is much lower than desired, it may be raised substantially by removing the yellow filters and using only the red ones in the fully closed vanes. Make certain the vanes close tightly to avoid leakage of yellow light."

Color Printing (Type DUC)
Yellow filters in the housing and Black (black tape edge) filters in the vanes. "For color printing papers, the vanes should be fully closed, so that light passes through the yellow and black filters. The light level will be rather low, bu t still many times brighter than conventional safelights. ..."

RPippin · Jan 25, 2012

My Thomas safelight has been "humming" along for about 3 years now. The noise is a bit of a bother, but I'm waiting for the bulb to burn out before replacing it, plus, I have a back up Thomas. Does anyone know what type of ballast and where to pick one up? I suspect the ballast is more the culprit than the bulb, could be wrong, but would like to find a replacement just in case.

frobozz · Feb 3, 2012

Here's a scan I made a few years ago of the instructions (such as they are) that came with my Thomas Duplex safelight:

http://backglass.org/duncan/darkroom/thomas_duplex_super_safelight_instr.pdf

Duncan

scheimfluger_77 · Nov 2, 2012

ParkerSmithPhoto said:
I bought a used $40 Thomas Duplex safelight today. The filters were kind of beat, so I replaced them with Rosco #19 "Fire" which has the right type of wavelength cut off:
...

How many layers of the Rosco filter do you use?

Steve

scheimfluger_77 · Nov 2, 2012

Leigh B said:
Rubylith is red. It will dramatically reduce the brightness of the monochromatic yellow sodium vapor lamp used in the Thomas Duplex.

Not a good choice IM[-H]O. :confused:

- Leigh

Leigh, you've mentioned using the #19 filters in other posts. Do you actually open the glass sandwich and replace the existing filter or leave the old one in?

Steve

Oops! Never mind, I read the later posts. Thanks.

I <3 Thomas Duplex

Leigh B

Helinophoto

ParkerSmithPhoto

Sundowner

ParkerSmithPhoto

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Sundowner

nsurit

Mark Crabtree

EdSawyer

Mainecoonmaniac

Richard Jepsen

Leigh B

Steve Smith

ParkerSmithPhoto

Newt_on_Swings

ParkerSmithPhoto

Mike W

smieglitz

Mainecoonmaniac

Mark Crabtree

RPippin

frobozz

scheimfluger_77

scheimfluger_77

I <3 Thomas Duplex

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