Help, Thomas Duplex Safelight

[Greg Davis]

The DUB filters fit in the holes that you look through to see the bulb. The other filters go in the vanes.

[Richard Jepsen]

Thanks for all your replies. Thomas Instruments no longer manufactures the safelight. They still make and sell parts and are reached at 434-842-9475. It is likely in our community DR we avoid fog issues as the ceiling is panted black and sucks up excessive light. A yellow filter coded FBD fits into the body as Greg mentioned. The vanes/wings hold a red filter coded FOD.

[Richard Jepsen]

I am following up on this post for historical documentation. The Thomas Duplex is a super model with two prong plug. No filters where in the body or near the top opening into the body. Installed in one vane/wing was a blue crinkled filter sandwiched by glass and the other vane/wing a dark orange/red filter. In replacement I hung a Kodak 10x12 OA light with 75w compact florescent. Fomabrom Variant VC-FB fogged in 2 min. Ilford WT FB was fog free after 7 min. The damaged Thomas Duplex Super output did not fog Fomabrom. As hung the Thomas Duplex light output was dimmer but wider coverage since it reflected off a black ceiling to the walls.

I teach a darkroom class and a student material costs are a consideration. Excellent less expensive FB papers are orthochromatic. It looks like the best path is to replace the Thomas filters with the ortho filtration.

[Greg Davis]

It sounds like your safelight was missing the FBD filters and had one FOD (red tape/ortho) filter and one FDY (blue tape/graphic arts) filter in the vanes. The normal setup is to have a set of FDB filters in the base and a set of FOD filters in the vanes for intensity control. I have a set of black edged FCD color filters in the vanes of mine and the FDB in the base. When open, the light is excellent for all B&W material and very bright. With the vanes fully closed, it is much darker, but still easy to see and safe for RA-4 color material.

[Richard Jepsen]

Greg, thank you for following this post. You have added to my knowledge. I'm considering ordering FOD filters. Are body filters a different size then filters in the vanes/wings??

Would you recommend some other safelight?

Above each enlarging station are screw-in light fixtures. Jumbo red bulbs @ 25W are na option. I can replace the Kodak 10x12OC filter over the sink with a 1A. The OC's direct illumination is brighter than the Thomas Duplex reflected-light. That may hold true for a 1A filter.

Purchasing (6) jumbo red bulbs and 1A filter for the Kodak unit is the most expensive option. However, who knows how long the bulb will last in the Thomas; especially after a crash from the ceiling.

[Greg Davis]

The filters are different sizes, preventing you from putting them in the wrong place. I only recommend the Thomas Duplex.

The filters for the Kodak lights fade very quickly if the bulb wattage is too high, so do not use anything stronger than a 25W, and I believe that is for reflected use. The wattage is 15W for direct light. You may want to consider painting the ceiling white to reflect more light from the Thomas. The bulbs last a very long time, but are expensive to replace, though I have found them online for $40 before. The filters need to be replace every few years.

Do not get red bulbs for safelights. They do not work properly. You can test your safelight using Kodak's guide.

[Phil]

I found some SOX35 low pressure sodium vapor lamps online that appear to be the same (or very similar) as the original lamp that was in my safelight - work fine for me, but I use AZO/LODIMA. Price was about what Greg mentioned -(a bit less, IIRC) Life is listed as 18,000 hours for these lamps. The one that was in my safelight did have a sticker that said it was a special photo lamp. As always, YMMV...