# I need a bright LED for a pinhole light source.



## iansmith (Jul 12, 2009)

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.


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## snarfer (Jul 12, 2009)

Why not try some sort of fiber optic?


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## Light Sabre (Jul 12, 2009)

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.


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## iansmith (Jul 12, 2009)

snarfer said:


> 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.


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## bshanahan14rulz (Jul 12, 2009)

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


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## znomit (Jul 13, 2009)

bshanahan14rulz said:


> 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


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## iansmith (Jul 13, 2009)

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.


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