Anybody playing around with backlighting?

[Rich Ullsmith]

I'm working with old Kodak transtar paper for lith, and I've got a lifetime supply of it. The prints look best on my light box, I imagine the same way a big color transparency does. Had some thoughts of building boxes for my big prints, but tubes put out UV and bulbs put out heat.

Now I'm playing around with LED's, and they seem like the perfect light source for a project like this. Anybody know anybody who is doing this? Re-inventing the wheel can be fun and rewarding, but I just finished my darkroom and six months of that took the wind out of me when it comes to problem solving.

 

[wilfbiffherb]

Afraid I can't help on the lighting front but I'm jealous of you're stash of the paper!

 

[Rich Ullsmith]

Yeah, it came up on Ebay six or seven years ago, three 100'X 42" rolls, and 3X50 sheet boxes of 24"X36". (Weird size.) But it looks great backlit. Not nearly the pop of a transparency, but different.

I'm thinking of a few boxes where I can change matted prints in and out. I just am in the brainstorming phase. LEDs that I can wire and power myself generally have a narrow beam, like 30 degrees. Probably the cheapest thing would be some string lights from Walmart, if they are bright enough.

 

[Vaughn]

Are you treating the paper at all to help with the transmission of light thru it? If the Transtar paper is a RC paper, probably not.

 

[TheFlyingCamera]

I've not done anything exactly like that, but I did build a light box for displaying 16x20 Duratrans color prints. It used a single fluorescent tube in the center of the box, and the interior was painted white. The front face was a sheet of white translucent plexiglass. The box was about 12"-16" deep. The advantage of doing it that way was I had no hotspots in the backlit display. The downside was the box was rather substantial and a pain to carry around.

 

[Rich Ullsmith]

No, not treating the paper. Not necessary.

I'm thinking a box maybe 4" deep, less would be better, with an array of LED's. I just made a safelight with red LED's, and there was more than enough power from a 12v 600mA wall-wart I had laying around. The whites are much brighter than the reds at the same wattage, so I figure maybe 40 bulbs would cover a 16X20 mat opening.

Maybe build a mini first, work out the details.

 

[pdeeh]

You could investigate EL (electroluminescent) panels.
Very thin, flexible, run on low voltage, available in different colour temps, can be quite inexpensive.

 

[Rich Ullsmith]

I did look into them, but there's not much OTC right now, it appears. Haven't called about them, but I will.