# Laser sheet effect?



## Sirius (Jul 18, 2009)

I just visited my first haunt of the season last night, and ran into an effect I've never seen before. A green laser projected into a flat sheet about waist high. Coupled with fog, it was like walking through a murky swamp, and hid spooks until they came rising up from underneath it. It was fantastic!

Does anyone know of a cost effective way to produce this? I found an old thread here about ADJ's "Galaxian Sky," but it's far beyond my budget.

A few ideas off the top of my head are:

1.) Mounting the laser to a motor and spinning it around fast enough to produce the sheet effect.

2.) Mounting a _mirror_ to a motor at a 45 degree angle, shining the laser down onto it from directly above, resulting in kind of a 180 degree laser vortex.

3.) Creating a makeshift lens from a piece of plexiglass, cut into a wedge shape and then sprayed with mirror coating except for where the light enters and exits.

Does anyone have any better ideas? Specific reasons the ideas above wouldn't work? Anyone made their own laser sheet projector?


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## CoolDJTV (Jun 28, 2011)

I am also intrested in this. please reply someone!


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## Sirius (Jul 18, 2009)

UPDATE:

Option 2 appears to be working like a champ. It's throwing a solid, flat line around the whole room. Going to wait until dark and hit the fogger. I got the mirror out of a $1 dental care kit at Dollar Tree, a battery operated mini fan and a scrap of crown mold for free(it was even already cut to 45 degrees for me!). The laser's the most expensive component, but I'm sure some nice folks around here can tell us where to get the best deal.


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## CoolDJTV (Jun 28, 2011)

cool, get some pics


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## MapThePlanet (Nov 12, 2010)

Sweet! GearXS.com has some pretty good deals on lasers right now, depending on what exactly you are looking for of course


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## Sirius (Jul 18, 2009)

Thanks for the tip, Map! Really good prices. They have blue-violet lasers too! That'd be a really nice look for this project.

Got some pretty good results from my proof-of-concept test last night. It seems that fog density needs to be fine tuned. I have a pretty weak fogger and the test was outdoors so it dissipated quickly. Trying again tonight, indoors and with a chiller. I'll try and get some video to post.


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## corey872 (Jan 10, 2010)

Sounds like you have it worked out pretty well. The spinning mirror was my first thought as well. If you search various novelty places you can find adapters / holograph film which will sit in front of the laser and project a line. Often you will see these on laser levels and some laser pointers come with them as well. 

Red and especially green lasers make a great effect. To really make a bright 'sheet' you need to have decent laser power...20-40mW or more. I probably wouldn't bother with the 'blue-violet' laser. They are actually a violet laser (think blacklight) - so the beam you actually see is pretty faint. They tack the 'blue' on there to get all the search hits from blue lasers - which are much more expensive for the same power, though do make a much more visible beam.


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## Sirius (Jul 18, 2009)

Very good info corey. What I thought was a fog density issue is probably the result of my only using a 5mW laser. 100mW is on its way now. I'll postpone the next test until it arrives. In the meantime I'll be building a frame to hold the mirror and laser components in the right positions. Now I'm really optimistic about this!


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## fontgeek (Jul 24, 2006)

Something you need to be careful of is potential eye damage/injury to both the actors and the guests. Having those lasers flashing into your eyes is not a good idea, and there is potential for some serious injury from it.


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## Sirius (Jul 18, 2009)

I think placement has a big effect on that. You have to work out a level high enough to hide spooks, yet still low enough that nobody(okay, nobody reasonably intelligent) will be tempted to lean down and peek below. Somewhere between knee and waist should be good. The one I saw was right about at my longest fingertip while standing upright with my arms relaxed. I would probably make it a little lower.

My haunt is a hayride, so I can be pretty secure by simply putting it below the level of the trailer floor. The effect is going to be in a dry creek bed and the trailer passes through on an elevated road, so that leaves plenty of hiding room.

Actor safety mostly relies on the actors themselves. Making special dark lenses a part of the costume could help, but might open the door to other dangerous situations.


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## fontgeek (Jul 24, 2006)

Rather than fight the dark glasses, train your actors to sit up or stand up with their eyes closed, that will prevent the potential exposure risk. The creek bed should help contain the fog a bit.


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## silentskream (Sep 20, 2012)

Please get pics of the setup when you get it put together!
im definitely interested in this.. would be a great way to "use up" unused yard space for relatively cheap.


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## RandalB (Jun 8, 2009)

Definately interested in a pic of your mirror setup....

I also agree about the green laser, I tried violet in my vortex last year and it didn't work well. 

Search Ebay for a laser module, I've seen 20mw ones as low as $5.95

RandalB


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## David_AVD (Nov 9, 2012)

I realise this thread is old, but something else you could try is a spinning faceted mirror as used in some laser printers. This would give a beam segment that extends only from one side of the mirror assembly so could be mounted at the side of the area instead of the middle of it. The driver motor is not a simple DC type though, so you may be best just using the special mirror and bearing with your own motor.


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## Lilly (Jun 13, 2006)

If the fog machine is used indoors you should make sure the room has adequate ventilation. Some people with breathing problems may have problems breathing while in the fog. It is a good idea not to breath the fog for extended periods of time. you may want to have a few scareactors to swap them in and out .
I'd like to see a vid or pics on this too sounds cool


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