I want to give someone a cool xmas present which consists of a simple circuit to activate a buzzer everytime someone walks past a laser beam.

Now I know it will be even cooler if I can make the beam visible from any angle (like in the movies). The question is how, and what its going to cost?

__________________
www.myspace.com/crimsonroadmap

 

use a smoke machine or close the damper on your fireplace ... soon enough the beam will be visible from any angle

to recreate what you see in the movies, you'll use a computer program to draw in those beams, one frame at a time, after you shoot the home video.

__________________
If you don't have a planet, what good are gold bars?

want to contact me directly? gmail gordonthree
check out my project website: http://projects.dimension-x.net
Favorite numbers:
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0

 

I think the only way your going to be able to see a laser as a red beam like in the movies is if you have smoke or dust in the air. The beam needs to shine on somthing for it to be seen.

 

Well the whole point of those is not to be seen, but if you really wanted to it could come with a bottle of baby powder so that the person could see it if they wanted to.

 

Water vapour also works well, plus it's non toxic and easily availible.

__________________
It may seem like a good idea at the time , but never stir your cold coffee with a soldering iron.

 

You can actually see green lasers with the naked eye, bu they might just get to expensive for your project.

 

I thought lasers that are strong enough to be seen mid-air means that they have hazardous/dangerous reflections (reflective surfaces obviously, but also diffuse surfaces that are dull)? And in the higher end of things, hazardous even for mid air viewing?

 

Mmmmm, I certainly wouldn't want to look one straight in the eye. . .

And the green lasers I have seen are WAY EXPENSIVE £££££££

__________________
'Intellectuals solve problems. . . Geniuses prevent them.' . . . Albert Einstein

 

Green lasers that are visable under average dim air conditions blind virtually instantly and will actually ignite matchheads at moderate distances. They also cost a small fortune. ThinkGeek sells 10mw one's and they have a 5 point saftey system to prevent from accidental turn ons (reading from the add). They always sell 5mw ones for 100 dollars, still dangerous.

If you just want the appearance of cool use a piece of fishing line and shine an ultra bright red LED or red LED laser, it'll emmit some light along it's length and if you shield the source it will look just like a movie style laser. Could be a good gag as well if you tie the line tight enough and use a heavy weight it'll actually trip the user instead of just an alarm =>

"Invisible" (mono filiment flourine or something like that) fishing line is almost as good as glass for short run fiber optics cables and you can use sand paper on the portions you want to show and paint or tape on the portions you don't.

__________________

 

I haven't tried it myself, but according to mythbusters, when you use the powder, smoke, or mist to see the laser, the "alarm" will trip. Seems obvious after it's stated, doesn't it? I had a "duhhh" moment when I saw it.

 

http://http://www.wickedlasers.com

 

It was wickedlasers.com which gave me the idea for it in the first place. But I'm not going to spend that kind of money!

__________________
www.myspace.com/crimsonroadmap

 

Light can't be seen until it hits something. The way they get lasers to show up in the movies is either with a smoke machine or by superimposing them with a computer. I don't care how high powered your laser is, the only way you will see it in mid air is with a smoke machine or by constantly kicking up a lot of dust!

 

The green lasers are high powered enough that incident water vapor and dust in the air will let the beam be visable in the dark under most common conditions.

__________________

 

Don't you need eye protection when playing with that laser?

__________________
I also post at the following sites:
http://www.stop-microsoft.org http://www.heated-debates.com
Screen name: Aloone_Jonez
And http://www.silicontronics.com, same screen name as here.