LED + magnifying lenses

I want to rig a couple of magnifying lenses in a tube on the end of my KL1. Do you think I'll be able to bring the light to a small laser-like beam that could throw hundreds of yards?

I must have too much time on my hands. /ubbthreads/images/graemlins/wink.gif

i was thinking that too, well, kinda but not really, i wanted to hook up a magnifying glass or condenser lens of some sort to the bezel of a C3, at the right point, so then i could set fires like i used to when i was younger with magnifying lens and the sun /ubbthreads/images/graemlins/smile.gif, i think that would be pretty cool, but i couldnt find such a lens. Let me know if you stumble upon something like that...id be greatly interested

A simple convex lens would produce a beam that converges at a given focal length then widens out - resulting in a flood past the focal point.


The right kind of narrow spot optic produces a beam that does not converge, but has a very narrow angle - typically 2-6 degrees that maintains coherence a long ways out. Some of these optics essentially mimic conventional reflectors; others use slightly different principles.

You might have some luck with a half-round optic - although they seem to have big efficiency issues.

If I can get the converging point to be at about 100 or 200 yards then the beam should keep shape enough to make me happy.

I was noticing the half-round optic idea. I'm going to looking into that some. Know of where I can get any?

you want to search for a plano convex lens. try edmund scientific

I ordered an LA1274 plano lens here . Hope it works. /ubbthreads/images/graemlins/wink.gif

do a search for NewBie/Jarhead's post on asphyrical lens. It was amazing how far and small of a beam with a lux3.
I think it was called alien light beam...

I'd love to do taht with a cyan lux3 I have...

I'm no expert, with that said I don't believe you can achieve that goal. I looked at the lens you bought the focal length is way to short. You would need something around 1000mm EFL if you are using just one lens.On the otherhand using a lens that long you'll not capture all of the light. Read about laser beam expanders. For a thorough answer I'd post this question on Google's Groups sci.optics or alt.lasers. You might try a keyword search such as led light collimation or some variation there of. I think "SAMS LASER FAQ" has info on this subject.