My home made laser show, with pictures

Hi, i have only decovered these boards a few days ago and they are very informative, and people seem to love lasers so
i thought i would post some pics of my home made laser show which i made with two $7 red laser pointers <5mw, a car speakers, lens mechanism from old dvd rom drive, mirrors and bluetack hehe.

This picture shows the first laser which goes with the music expanding outwards horizontaly only, i made this with the lens focusing mechanism from a now broken dvd rom drive connected straight to an amp with a small mirror superglued to the to of the dvd tom lens.

The second picture shows the laser show made from a car speak with mirror attached, works very well and doesnt just move horizontally, you get up and down as well and nice patterns on some parts of songs.

The the other two pics show it in action, i use a smoke machine to get the full effect! smoke machines are a must and i highly recomment people to get one, makes lasers to 50 times better, and they only cost $70-80! It looks much more exciting when its actually going with the music, still pix dont do it justice!

let me know what you think.
/ubbthreads/images/graemlins/buttrock.gif

pic 2

pic 3

pic 4

Edmund Scientific used to sell laser light show kits back in the 70's.

I made a light show without lasers by using a slide projector with a pinhole as the light source, a cheap speaker for motion, a broken piece of balloon over the speaker as a diaphgram, and then mirrors hanging over the front of the rubber, held by a thread.

With 3-4 mirrors on there, you would get really cool patterns on the ceiling. Good bass makes a big difference.

Scott

I once saw somebody put a layer of cling-wrap over a speaker. They then glued a mirror to the wrap. Add sound and point a laser at the mirror. The ultimate in "ghetto" laser shows! This was a LONG time ago. The laser was a HeNe tube, as semiconductor lasers had not yet been invented.

Man, I need to do that with my 40mw laser. It's still pretty cool to shine it on CD's and stuff. I have a few pics.

hey not bad dude, i like the bottom picture, is that with the CD? its pretty kool! ;O)

you need to get a smoke machine, its the best investment, the green bream would be so bright! cant wait to get my green laser delivered!

Yeah that's with a CD. Pretty sweet. While you are at it check this out.

I've found that shining a green laser at various household items can produce some interesting results -

Shining it at some crinkled up cellophane produces some wild patterns. Be careful about glints though!

Aiming it at almost any fluorescent orange object renders the green dot as an interesting-looking yellow.

Aiming it at a piece of wax paper (be careful about reflections) produces a nice diffuse source of green light.

Now that my laser is waterproof, I have shone it in my sink. Something puzzles me though. If the laser is totally immersed in water, shining up at the surface, the beam doesn't penetrate it and go into the air, it just reflects off of it. Does anyone know why?

Fot the same reason the NX0X and Fraen optics work.... /ubbthreads/images/graemlins/grinser2.gif

Which is....

The speed of light differs in two mediums.

Refraction!

Hmm but the thing is it doesnt penetrate the surface at all. It's like its a mirror. Not refraction, reflection. I am talking about like if you are at the bottom of a pool with the laser shining up. The laser doesn't go through the surface of the water.

There should be some refraction taking place, however slight it might be. When light goes from a material in which it travels at a relatively low speed, to a relativly high speed, it tends to bend towards from the normal line (the line perpindicular to the surface of the water).

If you shine the laser from underneath the water at a 45 degree angle with the surface, the refraction will cause the light to travel at a new angle of 70.13 degrees (but from the other side) with the surface (if I did my calculations right /ubbthreads/images/graemlins/tongue.gif).

You may not be looking the right right spot for the laser. It might also depend on the smoothness of the surface (waves or calm). I would be really amazed if you get no light penetrating the surface though. /ubbthreads/images/graemlins/confused.gif

high school physics... One of the best combination of PITA and useless...
It still gives me the creeps. /ubbthreads/images/graemlins/tongue.gif
As IlluminatingBikr pointed out, it will penetrate if you shine it at a higher angle (put it perpendicular to the water line will avoid the internal reflection). The beam will also deviate a little due to refrection so carefull with your eyes!

The reason you can't see the beam is a phenomenon called "total internal reflection". If the laser is aimed more or less straight up though, the beam should break the surface of the water and shine upward. Watch the eyes though; as any waves or ripples in the water will deflect the beam, in what would first appear to be a random or chaotic manner.

I made my first "laser" show around 1980 by taping a piece of a broken mirror to the cone of a speaker, and aiming an automotive tail lamp bulb focused with a long focal length lens at the mirror. When music was played through the speaker, especially low frequency or high risetime waveforms (like bass axes or drums), the mirror would vibrate and provide a light show on the wall.
In 1981 or thereabouts, I got my first real commercial laser, a Metrologic ML-800 orange-red HeNe, and I used that instead of the automotive bulb and produced better patterns.

If you can get the azimuth adjustment assembly out of an older laser disc drive (the kind that use a HeNe laser), you can create crude, but usable lissajous patterns with it and the laser of your choosing.
Do not input more than 2 watts per coil in the azimuth adjustment assembly, or you'll burn out the coils.
I know this from reading, and from first-hand experience. I've burned up a few sets of these over the years.

Hi everyone, im new /ubbthreads/images/graemlins/blush.gif How did you get your laser water-proof? sorry for the long time span but i need to know /ubbthreads/images/graemlins/wink.gif