# Looking for an aspherical high power LED



## Fearis (May 19, 2013)

Hi!

I've built a quad copter and want to add a LED light to it which illuminates the ground the quad is flying over to ease navigation in the dark.
I am looking for a bright LED with an aspherical lens on it. Ideally it'd be ready for 12V (5V or anything else below 12V is okay, too).
The whole setup has to be light, so attaching a dedicated flashlight with a big clunky aspherical lens is out of the question.

Color reproduction does not have to be the very best, cooling is probably not an issue either as the LED will get cooled by the surrounding blowing air.

Thanks for any suggestions!


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## jspeybro (May 20, 2013)

Hi,

I have several sizes fresnel lenses that could be perfect for this.The lenses are only a few grams heavy. 
i have 25mm, 38mm and 50mm lenses. Using a lathe, it's fairly easy to make a plastic holder for the lens so all you would need is a heatsink to hold the LED and the driver (DX SKU 26110 is a nice cheap and small driver that fits your voltage range).
I made a few holders for the 25mm lenses that you can screw on the brass part of a P60 style drop-in so you can focus it and lock it with glue. 

Check DX for a dropin that you like, and PM me if you need lenses and holders. check my signature for some examples.

regards
Johan


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## TEEJ (May 20, 2013)

Why aspherical?

Aspherics give a very small spot of light on the ground....is it because you expect to be so high up/far away that you are assuming that a non-aspherical would not have the range?

If its for navigational purposes, a floody beam would be a LOT more useful for example, as you'd see enough to have some context, etc.


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## jspeybro (May 20, 2013)

TEEJ said:


> Why aspherical?
> 
> Aspherics give a very small spot of light on the ground....



That is only if you put the LED in or just behind the focal point of the lens. If you put the lens closer to the led, you get a nice even divergent beam of any size you want.


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## TEEJ (May 20, 2013)

jspeybro said:


> That is only if you put the LED in or just behind the focal point of the lens. If you put the lens closer to the led, you get a nice even divergent beam of any size you want.



Is that depth change what Lenser for example uses to get a zoomable push-pull effect?


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## jspeybro (May 20, 2013)

more or less. They seem to be using a TIR optic which is a combination of a lens and a reflector. The lens part (center part) will have the same effect as with aspherics. The reflector helps you making use of the light that is not going through the lens and would be lost if you only use a lens.


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## AnAppleSnail (May 20, 2013)

As long as the camera is pointed along the axis of the beam, this could work. But using a light source to see through a camera at night requires VERY BIG lumens. I don't think you'll get much image with a 'standard' digital video rig (Cell phone camera as benchmark) beyond 50 ft altitude.

Edit: That said, this beam will help to show where the craft is, and make crazy strobe effects as the copter tilts. A high-output LED will need enough heatsink to take heat away, but not a large chunk of stuff.

The Coast/LEDLENSER lights use either aspherics or a combination lens that is part of their patented stuff.


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