I was wondering if its possible to build a UV light box with LED lights. I know some people have used them for enlargers, but didn't find information about the use of LED lights for alternative printing.

I read Sandy's article on unblinkingeye and it seems most processes are sensative to the range of: 320-400nm, and others up to 450nm.

So I was reading up on LED lights and found the following types.

375nm (peak) 350-410nm (range)
395nm (peak) 350-440nm (range)
426nm (peak) 400-450nm (range)

If I were to make an array of these lights, wouldn't it be possible to use this as a UV exposure unit? Print things such as, Kallitypes, Platinum, Palladium ect...

What are your thoughts or suggestions on this?

Regards,
Martin

I am putting together my own UV box right now and considered what you suggesting. However, I opted for my first design to use a proved type. I am interested in what you might find out.

Will the LED's act like point source lights and cause sharply defined illumination areas? This may be sorted out I suppose by ensuring "sufficient" stand off between light source and image area.

I remember reading that above 375 nm there were increasing losses due to absorption by the cover glass of the printing frame so perhaps unless you are using a vacuum frame this may be of concern to you.

I think it is a wonderful idea to try. The LED efficiency is legendary and would surely be lighter. I wonder about the economics of construction. What is the pricing like? They should far outlast the fluorescent tubes we are using and the heat factor should just about be gone.

Have you thought of building a simply 5 x 7 or 8 x 10 size device and testing?

If you got for please let us know how it turns out.

Regards

Mark MacKenzie

Possible, yes. And yes, LED are efficient, but so is mercury vapor and the rest. And efficiency isn't that important in printing. LEDs are expensive and they are very much a point light source. This means that there needs to be a lot of diffusion. Diffusors are inefficient. So it could be done and if you wanted to use all your spare time for a couple of years, you could probably make one that as good as one you could buy today for less money. Better off taking more pictures.