Thread: Beam of white light

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For a project i'm working on, I need to find out how to make a beam of light. Almost like a laser beam... no angle (or very little). The smaller and brighter the beam the better. Anyone know how to go about making this?

how small a 'beam' do you want? and of course you'll need 'fog' or something in the air to reflect it so you can see it, unless of course you're using it as a spot light.

I don't actually need the beam to be seen. I just need a white light that can shine 20-30 feet, and still be just a small spot (probably 2" or less) on the wall, rather than spreading out.

Sounds like you need a bright light in a sealed box with a couple of lenses in front of it to create a point.

Just thinking out loud here...I have no specs

I notice my 3 D-celll maglight flashlight had a pretty powerfull beam the other night when I was shinning it into the sky. It was 4th of July, so the air maybe was a bit smokey. Maybe you could shine it through a lens or a pin hole cover to reduce the diameter.

I recall an experiment I did a long time ago where I shined a small 2 AA cell mini mag light through a $15 rifle scope to get a focused output.

Another way is with a sheet of polished sheet aluminum from Home Depot and a jobsight spotlight (halogen). Make a cylinder out of the sheet and just play with the cone-ness shape of the tube until you get the focus you're looking for. Like HalloweenBob, I'm just thinking out loud.

A few years ago I made a vortex using a cheap outdoor holiday projector. To get a pin point of light I took black craft paper to blacken out the slide card and put a small hole in the middle. Worked great!

A cheaper alternative to a projector might be one of those spotlights that you plug into a cig lighter in your car and claim to be Millions of candle power like the one below.



Usually you can get them for around $20 or maybe less on eBay.

Thanks for the replies guys! I didn't know if a small hole in cardstock would focus the beam enough or not. I'll go start trying some things out and see what I can come up with!

two syllables - FRESNEL

its a theater light that is designed to do both spot lighting as well as 120 degree lighting - also comes with brackets for gels (theater speak for color filters). they are designed for theater use - so they have a very small profile with little light spill (no one should notice the unit from the side).

here are some links:
google search

web site

handy link for anyone interested in theater light optic theory


and i know, i know - its a bit pricey. but if you store it well and take care of it - it should out live you!