Theatrical Effects: Replicating a Pyrotechnic Effect Without Any Pyro

No pyro? What fun is there in that? Well, unfortunately, for Woodbury Community Theatre's prodution of the Wizard of Oz, the high school would not let us use pyro in the theatre (And anyways, hiring a licensed pyrotechnician for the shows would cost over 5 grand, plus the cost of filling the necessary paperwork.). Oh, well. I guess we will have to figure out how to make all of the nice effects without any pyro...

The effect that I am going to be replicating is a firecracker. The effect needed to produce a large quantity of light in a very brief period of time, mimicking the flash from a firecracker, or an airburst, or a small amount of flash paper. The flash that is required is larger than usual, because theatrical lighting is much brighter than usual, around the house lighting. 

Here is a video of the demo board that I created for this Instructable. I apologize for my camera's inability to adapt to the rapid flash from the device.

Step 1: Different Methods of Creating this Effect

I thought of several methods to solve this issue. Each effect has its own set of pro's and cons, that I will detail below.

Effect	Description	Pros	Cons	Safety
Pyrotechnics	We hire a licensed pyrotechnician to come in and rig the witches broomstick with a pyrotechnic flash.	Large flash and a bang, syncronized perfectly, a small amount of smoke Flash eminates from broomstick	Extremely Expensive Only one flash per "loading" of the prop	Moderately Safe
Focused Incandescent Fixture	We position one of our ellipsoid fixtures and position it to illuminate the end of the broomstick, coupled with theatrical fog to simulate an explosion.	Bright flash with smoke Zero-cost Can syncronize with sound effect to create bang	Impossible to point, and repeat for each flash (The actors would not be able to hit the exact same spot, every single time) Incandescent bulb heat up time doesn't create a quick flash (Think cheesy theatrical/movie lightning)	Extremely Safe
External Strobe Light	We rent, and mount a large strobe light on one of the flies, and use it to illuminate the entire area.	Bright Flash Low cost (We have a company nearby who rents to DJ's for extremely low prices) Floods the entire area	Fairly hard to syncronize to bang (internal variances in strobe light can cause the bang to happen before or after the flash, ruining the effect.) Flash does not eminate from broomstick	Extremely Safe
LED Strobe Light	We build a small LED-based strobe light, which can be mounted in the tail of the broomstick.	Fairly low cost An excuse to use high power LEDs Lower voltages keep it safe Flash eminates from broomstick	We would need at least 20 LEDs to create a large enough flash, so disguising the flash unit would be hard Fairly hard to syncronize to bang	Extremely Safe
Disposable Camera Flash Strobe	We disassemble a disposable camera to steal the flash unit, mounting it in the tail of the broomstick.	Zero-cost (All parts were found in my basement) Bright flash An excuse to tear apart a disposable camera and use the high voltage stuff inside (Haven't you ever wondered what was inside one of those things?) Easily disguisable (Flash tube is small, and battery pack can be hidden in the tail) Multiple flashes can be achieved without having to reload the prop.	Fairly hard to syncronize to bang. Extremely high voltages can injure actors if misused or misbuilt	Moderately Safe

As such, I decided to go with the Disposable Camera Flash. To combat the cons of this method, I came up with the following solutions.

1. Synchronization: To synchronize the flash to a sound effect, we created a two part effect. The first part was a "charge up" sound effect. This lasted about 3 seconds, and was promptly followed by a large bang, with some thunder mixed in. The plan was to fire the sound effect when the witch pointed her broom, and then she would fire the flash right before the bang happened, so they occur simultaneously to the audience.
2. Insulation, insulation, insulation. To protect the actors and the techies in charge of preparing the broomstick, I wrapped the PCB for the flash in a layer of Gaff tape, which provided a thick insulating layer, but still provided access to the charge button and battery holder. I also double insulated the connections at the flash tube, with a double layer of shrink tubing, and multiple layers of clear packing tape around the tube. This was a very important step, as the ends of the tube carry 300 volts constantly when the flash is fully charged.

Comments

[thegeeke]

Nicely done! As someone who grew up programming intelligent lights for theater, I have 2 more suggestions about how this could be done.

1. Position an elipsoidal, ParNel, or Scoop behind the actor (or just to the side) so that they are pointing into the audience. Preferably 2-20 fixtures. Use plenty of haze (preferably haze and not fog). At the correct time, flash your lights behind the actors so that it gives an intense effect towards the audience making them feel like the broomstick was pointed at them. It get's really fun if you can use gels and do different colors.

2. Use as many intelligent lights as possible strobing different colors, positions, and if you have any decent gobos for the effect use gobos as well on the person the broomstick is pointed at. If you do it right, the lights should be only on the person the broomstick is pointed at, and the audience will be so dazled by the sudden lighting that they will not even notice that the broomstick didn't have any effects on it. It takes about an hour to program this sequence and it only lasts for a few seconds, so don't think this is the easy effect. ;)

There are other ways of doing it, but these two (aside from pyrotechnics) are my favorites. Your ible is a fantastic option for groups that have extremely limited resources though! :)

[thegeeke]

Oh, with the static fixtures, don't flash them all at once, do them one or two at a time (depending on how many you have) randomly for a split second each. :)

[pjensen]

I considered most of those, but due to the staging (the actress was up on a 4 foot tall platform at the very back of the stage), it would be almost impossible to get the lights positioned correctly for the effect.

In the space we were using, there were 8 old intelligent washes that we could have used to finish up the effect, but they don't produce very much light... I have done something similar to your #1 suggestion before, and it has worked great, but it just wouldn't work in this situation.

In this same show however, I did use a combination of an ellipsoid with a lightning gobo and the intelligents on the scrim to produce a stunning lightning through clouds effect. With everything flying behind the scrim (Remember, this is the Wizard of Oz, specifically the tornado scene...), the effect was perfect.

[thegeeke]

Yes, I understand that the ideas I stated would not work in every situation, but I didn't see them in your effects list at the beginning, and since the idea for this instructable is to help people with their theatrical effects and based off of your picture I would say I got started in theatrical effects (lighting, sound, etc.) just about the time you were born, I just thought I would throw that in. ;) (Like I said, good job! As a matter of fact, I probably wouldn't have even thought about doing it the way you did.)

[pjensen]

I agree, I probably should have included them, but I kinda forgot about it... Oops...

And second, Thanks!

Who do you do lighting for?

[thegeeke]

I own a media production company, I mainly do freelance sound, but I still dabble in lighting from time to time. I started in sound for my church when I was 7, and I started doing intelligent lighting for community theater when I was 8 or 9. Most of my real "training" is in intelligent lighting, even though I consider myself more of an audio guy than lighting. I enjoy both though! (And since my first "real" job was at a climbing wall, I also train people on how to work on lighting and rigging.) :)

[SelkeyMoonbeam]

This is really neat. Do you have any video of it working?

[pjensen]

I do not, but I can get a video of my demo board working. Unfortunately, before I could remove the actual board from the broomstick, the props people had taken it, and I have no clue where it has gone.

I will work on that right now, and it should be ready in a couple of hours.

[pjensen]

Well, I tried. Very hard. The problem is the device produces too much light for my camera to capture. When I try to do a walk-through of the device, and I fire the device, all you can see is a completely white screen. If I decrease the exposure, you can't the board, all you can see is the flash.

I can still post the video, if you want to see the white screen of the flash.

[SelkeyMoonbeam]

Thanks, I am excited to see!

[pjensen]

Done!

[SelkeyMoonbeam]

Thanks, nice video!

[CarpePM]

Well done. Very creative.

[pjensen]

Thanks!