Red LED lighting for the darkroom

[Fulvio]

Next month I will start setting up my darkroom. Seriously this time!

Instead of using traditional red or yellow-green safelights I was thinking of using small arrays of LED lights. They last much longer and they're much more resistant, especially if you move them frequently while a tungsten lamp might broke and they cost quite a lot...

Just stick a 6-8 LEDs inside a diffuser (e.g. a plastic semitrasparent cartridge for 35mm film) and use a dimmer to change intensity of light. One could also put a swtich to select between red and yellow-green.

I guess it won't be difficult to build this as the design requires very basic knowdlege. The only problem could be LEDs wavelenghts... Which wavelenght should I use to prevent paper fogging?

I know that I could use regular household low wattage light bulbs inside red filtered lamps... But if it is easy to get the right LEDs I would prefer to try those anyway...

cheers

 

[Bob F.]

If you do a search here for LED safelight you will find a number of posts on the subject. The simplest way is probably to use a single Lumiled LED. You will only need the one - they are very bright. I use amber which gives me over 15 minutes safe time, but if you want to be even safer, use a red/orange one. VC paper seems to run out of steam at 550 - 600nm wavelength; graded paper even earlier. The Lumiled datasheets show the wavelength of each colour LED.

Cheers, Bob.