I need a bright LED for a pinhole light source.

[iansmith]

I have been experimenting with making pinhole light sources out of 5mm LEDs.

What I do is sand down the lens as close to the actual emitter as I can get, polish it, then cover it with a thin bit of metal with the smallest pinhole I can make in it.

(Click for bigger image)

I am currently using a RL5-W18015 which is rated at 18,000 mcd (no idea how they measured that) and it works, but I need as much light as I can get so I am looking for a replacement.

Since I remove the lens, the beam width doesn't matter to me.

And unlike most applications, the size of the emitter does matter. A large emitter like in a Luxeon is not as usefull since I will be covering most of it up and so most of the light will be blocked.

Any suggestions? Out of the box ideas are welcome too.

 

[snarfer]

Why not try some sort of fiber optic?

 

[Light Sabre]

At Newark Electronics I found a 18000 mlm (I think that's another way of saying mcd) 5mm white LED. Newark p/n 52K5249. TT Electronics OPTEK Technology p/n OVLEW1CB9. Cost was $0.934. I love how they use thousandths of a cent in their pricing.

Haven't found any 5mm LED's that are over 18000.

 

[iansmith]

Why not try some sort of fiber optic?

I suppose because I dont have any handy to work with. I'd need to focus the light onto one end I presume.

 

[bshanahan14rulz]

snarfer's idea is pretty good. use a condensing optic on a high-power first, then cover the end of that with the pinhole shield

 

[znomit]

snarfer's idea is pretty good. use a condensing optic on a high-power first, then cover the end of that with the pinhole shield

+1
Something like this polymer optics XR-E concentrator
http://www.polymer-optics.co.uk/Cree XR-E Optics Range Brochure.pdf

From here
http://www.cutter.com.au/proddetail.php?prod=cut191

 

[iansmith]

I'll keep a lookout for some spare fiver and a good condenser lens. The web page with the Polymer Optics lenses were good, but the smallest I could find was one that focused on a spot 6mm wide. I imagine I should be able to find a lens that will get it down to a point since the fiber is going to be very thin.

I ordered some 55,000mcd lenses from ebay, I'll try those out too.