Are collimated LEDs at all useful / interesting / worth exploring?

Lol, but that's two light sources combined (don't need the green at all), so it doesn't count.

Mister wolfman, LEDs don't suffer from COD.

I'll try making a "laser beam" out of an LED later if I remember. It'll be pitifully dim, but it should work.

Cyparagon said:

Mister wolfman, LEDs don't suffer from COD.

I'll try making a "laser beam" out of an LED later if I remember. It'll be pitifully dim, but it should work.

Click to expand...

Thats what im saying! Dim or not you could have any color you dream of and still fit it in a pen unlike RGB projectors.

It works fellas. Give me a few minutes for photos

EDIT: Enjoy


Ghetto Fabulous Custom Cree Flashlight with high dollar tinfoil and pinhole upgrade!




Before acrylic aixiz lens. You can clearly see the shape of the Q5 emitter



After lens - Seems collimated to me but divergence is quite bad



The dot is less than 1/4" from 2 feet BUT this is a pinhole I simply eye balled with a thumb tack.


I think it would work better if the pinhole was closer to the emitter. In this design the pinhole is like 1.5" from the emitter.



EDIT2:

I got the divergence down quite a bit buy taking all the optics out and placing the pin hole directly on the clear dome of the emitter. Now its about 1" at 30 feet!


Now whether its possible to get the divergence down to that of a laser I am unsure. Im poking the smallest hole I can manage and its still worse than any laser I have ever owned.

One thing I also noticed is that theres no way to create a focal point like you can with a laser....so that leads me to think this isnt the same. Im sure someone with more knowledge than I can explain this.

Thanks, now I don't have to do it. Beamshots?

Even with a smaller hole, there comes a limit where diffraction around the hole's edged will offset the smaller hole and increase divergence.

It might be better to try it without the reflector.

Cyparagon said:

Thanks, now I don't have to do it. Beamshots?

Even with a smaller hole, there comes a limit where diffraction around the hole's edged will offset the smaller hole and increase divergence.

It might be better to try it without the reflector.

Click to expand...

Dead fog machine and I already put the flashlight back together s no beam shots ATM. I did try it without the reflector and putting the pin point directly on the emitter dome and it worked better. I noticed that with the smaller holes the one edge of the dot is red and the other is blue. Pretty cool.

Although the results are promising im skeptical since it doesnt focus like a laser for some reason. With a laser you can make a large clear circle and focus it to a point but with this it just goes from a blurry dot to a focused one and then back to blurry.

Step 1: find the biggest asphericens you can find. 3" varieties are often found in car headlamps, and clear "aftermarket" versions of these aspheric lens are available at a certain HID retrofitting forum that is pretty much its own planet.

Step 2: find the LED with the highest surface brightness. I think the XR-E R2 is still king here.

Step 3: focus to image LED at distance

Step 4: pretend that the beam is really thin, because as beam diameter decreases, divergence increases

^ Haha. I love #4.

Hehe.. seems like a fine recipe to build a throw flashlight, but it won't be a laser by a longshot

Benm said:

Hehe.. seems like a fine recipe to build a throw flashlight, but it won't be a laser by a longshot

Click to expand...

Well it cant be a "laser" of course since its different physics involved BUT if you could simulate the appearance using common materials that would be pretty cool :beer:

Just get a nice short-arc light. much higher surface brightness, easier to get lower divergence without a gigantic optic