Lasers for stage use

[richcraft]

Thanks ever so much RGB, this is all a big work in progress, so I think as you suggest both a smoke and haze machine would be the next advisable purchase, plus a trip to the local 'laser' authority to check usage rules!

I'll let you know what I find out...

[White-Light]

TBH there are many members on here who can help you much more with this than I can as they are far more experienced with lasers. Its just important not to get carried away with power levels over safety. I wanted to audience scan with my laser but got reminded of the dangers by others on here. A high power beam looks great, but only if you can still see it!!!

Mind you a blind magician pulling off the trick would be pure magic!

BTW I think it was Buffo who thinks you should have both machines. I have no experience with machines myself so can't advise you in that. Buffo is one of the more experienced members on here.

[buffo]

To clarify my earlier post re: hazers and foggers....

A Hazer produces a very fine, almost invisible haze of particles. This will produce an even reflection of the beam, and if the lights are turned down a bit on the stage, the audience will not really notice the haze.

However, smaller particles scatter light at shallow angles, which means the beam looks brightest when it's coming straight towards you. From your description, however, I think that the beams will most likely be viewed from a direction perpendicular to the beam travel. In this instance, haze alone will not produce the brightest looking beam.

That's why I suggested using the fog machine to augment the effect. Fog machines produce larger particles than hazers. And larger particles tend to reflect the light at larger angles. Thus, a fog made up of large particles will tend to make the beam more visible at 90 degree angles, because of the larger reflection angle.

You can test this yourself at home. Turn your laser on and light a cigarette. Blow some smoke in the beam and let it diffuse around the room a bit. Now look at the relative brightness with the beam more or less head-on and then from the side. You'll see that with the fine-particulate from cigarette smoke, the beam is much brighter head-on, but rather dim when viewed from the side.

Now take a chalk-board eraser, or a dirty rug, or some other dusty item and shake it in front of the beam. Have a look at the beam from the same two vantage points. You'll see that the beam looks a *LOT* brighter from the side now, because of the larger particles.

I suggest you have the hazer running for the whole act (because no one will really notice the light haze), and when you get ready to bring out the laser prop, have it appear from within a cloud of fog from the fog machine. (By using the fog for dramatic effect, people won't connect it with the laser prop.) The fog will stay in the air around the stage for a short while, giving you a very vibrant-looking beam as you switch the laser on. Then, as you go through the act, the fog will stick around for a few minutes, but it won't be obvious that you used the fog machine just to make the beams visible - it will simply be "left over" fog from the introduction of the laser prop.

When the trick (or tricks) are done, you switch off the laser. If you time everything right, the combination of the haze and the residual fog will give you the best of both worlds without having to continually pulse the fog machine... The beams should be very visible for at least several minutes. More than enough time to finish the trick(s).

As for the beam expander, what you want to do is enlarge the beam (diverge it) and then bring it back into a more-or-less parallel beam again. You'll need a concave lens to do the diverging, and a convex lens to bring it back into line. Together, these two lenses are commonly referred to as an "up-collimator". Google around and you'll find many examples. However, in your case you'll need something very small to work with the hand-held lasers. Normally an up-collimator will have the lenses mounted several inches (6 or more) apart. That's not going to work with your application, but you might be able to pull it off with a pair of high refractive-index lenses... (The greater the refraction, the closer the lenses can be placed together.)

Still, I'm wondering if you're aiming for something that is out of reach. I'm thinking that it will still be too large for you to palm effectively. But you'll just have to experiment and see what works I guess. (Fiber would be another option, but now you're getting really complex...)

Adam

[richcraft]

Adam, I can't thank you enough for your input - such a nice and informative forum!! I think you're spot on with the haze and fog machine, I'll try the 'test' you suggested at home tomorrow, but I do see what you're talking about. I had wondered why it was brighter/dimmer from different angles, that answers my question!!

I can run a lot of these items - haze/smoke - from remotes to turn them on and off when needs be, so timing won't be a problem, and the effect you describe of having the fog left over will work perfectly as this is all going to be part of a much bigger act, this is just one section of it.

I think I'll try without the expanders for now, but I'll have a little search on google to see if there's anything out there to suit should I need it.

Thanks ever so much again,

Rich

[allthatwhichis]

Heh, hang around here too long and you'll be running the hazers and foggers off DMX control or something.

[buffo]

Happy to help out, Rich!

One other thing... The UK members here are planning a Laser Enthusiast's Meeting for sometime in December. I *strongly* encourage you to attend. You'll find a whole bunch of people there with all sorts of laser equipment.

It's a great place to meet new people, make new friends, and learn a lot about lasers and laser projectors. It's also a great way to check out some of the *very* cool equipment that is on the market today without having to deal with pushy salesmen or industry reps - just a bunch of hobbyists. (Plus you'll probably get to see some awesome laser shows!)

These events are basically a social gathering with lasers. So it's pretty laid-back. And yeah, everyone here plays nice! Newcomers are welcome. I think you'll have a lot of fun, and you can probably get some good advice re: the collimating lenses you're going to need for the beam expander, as there will be some *very* knowledgeable people in attendance.

Have a look in the Meet and Greet sub-forum and check out the threads related to the next "UKLEM." You won't be disappointed!

Adam

[richcraft]

Adam, you are indeed a gentleman and a scholar - thanks so much chap! I'll definitely be attending the laser meeting, that sounds like it'll shed a lot of light on the subject (pardon the pun...!!!) I should have something concrete sorted by then as well, so I should be able to provide some input of my own!! If a little newbie-ish..... lol

Thanks again chap,

My Very Best Regards,

Rich

[Lasermad]

Hi Rich

Im glad you popped along here , as i said at the time 500 heads are better than 1 :-)

My own thoughts are UK H&S is going to be difficult to overcome , each county has its own rules ... the best way to overcome this is to become megafamous so you will essentially be left to do what you want as everyone will presume its all safe and no one will question it :-)

But first you have to acheive the affect ..which you are working away at ... and im sure woth help here you can acheive that

PAUL

[Jem]

Looks like there'll be competition for the stage area at the December ULKLEM½.

Carl with the laser harp and now a magician

I do hope i'll be able to make it...

Jem

[aijii]

Excellent.. I'll get loads of cash back when I sell off the class 4's and replace them with pointers and bigger fogger...

fucken smartarse pom