Amber LEDs for darkroom safelight?

[Daravon]

I have a safelight made from a red Cree I bought on Dealextreme. Very bright and works awesome; it's just screwed to a computer heatsink with an LM317. However I got an incandescent amber safelight and discovered that an amber safelight works well and is much more comfortable to work in, due to the spectrum. I would like to make an amber LED safelight; where can I buy an amber Cree-type LED? And what is the output spectrum? Thanks.

 

[blasterman]

You can get an amber Luxeon K2 star from LEDsupply for $7.00. Spectrum is 590nm.

Not sure if Cree even makes an Amber.

 

[Daravon]

Thanks for the info. I'll check the paper sensitivity spectrum and see if 590nm will work.

 

[blasterman]

I recall it being 550nm, but it's been a few years. I had a zone system class in college, and it was a conventional amber safelight the instructor had turned up too high. So, it was fogging all our paper.

Amber/red LEDs are far more spectrum specific and safer to use with variable contrast paper. Dimmed enough amber would likely be safe for color materials as well.

There's a classic test to see if your safelight is fogging paper. Just toss a unexposed sheet of paper in a developer tray under the safelight, and toss a quarter on it. Let it sit for 10-minutes, and then develop it. If you can see the shadow of the quarter the safelight isn't safe.

 

[hank]

There's also a red-orange, which is a little easier to see by than red.

Or using two or three dim red lights, I always found, helps a lot -- gives things shape.

 

[Daravon]

The LEDSupply amber LED is not safe with some RC papers. I'm back to using my red cree. I can switch back and forth but I will probably just stick with red. It's very bright and very safe.