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A Mushroom Cloud to "wow the audience"

Discussion in 'Special Effects' started by shannonlusk81, Jun 14, 2017.

  1. shannonlusk81

    shannonlusk81 Member

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    Lord save me, My artistic director has decided after a two year run that the video of an atomic bomb test isn't enough and he'd like to replicate a mushroom cloud on stage.

    We have a vertical fogger currently mounted under the center of the stage for an unrelated effect so I'm hopeful that someone, anyone, might have suggestions for a way to use this fogger to make said cloud.

    All other suggestions are welcomed too, I'm just at a complete loss...
     
  2. sk8rsdad

    sk8rsdad Well-Known Member Premium Member Fight Leukemia

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    The physics of mushroom clouds make it difficult to fake theatrically. You need a rapidly rising column of hot gas hitting a cold, dense layer of air where it disperses. Something like a Chauvet Geyser could work to emulate the rising column. You might be able to use some sort of obstruction or downdraft fan to get it to form the mushroom cap.

    At around the 1:10 mark of this video there's a geyser pointing downward at the floor that looks about right, except it's upside down.

     
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  3. Skervald

    Skervald Active Member

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    Wow. Fun project. Here are a few random thoughts:
    • As @sk8rsdad said, it would be interesting to experiment with some sort of downdraft above your current fogger. Fan speed would be critical as you'd have to be careful not to disperse the verticle column.
    • There are a lot of factors to consider (timing, lighting, set configuration, desired height/ size of cloud, the output of fogger, etc.) but would it be possible to put some kind of physical barrier over the vertical fogger that wouldn't be visible? @sk8rsdad is right, the upside down geyser looks about right because it spreads out when the fog hits the floor. If you could replicate this right side up, you might have something.
    • I think a quicker dispersing fluid would help define the shape a bit.
    • Could you use multiple foggers somehow? I'm sure there are others but those geysers can be mounted sideways as well as upside down. Perhaps your current fogger functions as the verticle column and a couple more get flown in to form the mushroom top. Again, production details, the space, and budget are going to dictate how possible this is.
    Please post your experiments and final product here. I'd love to see what you come up with.
     
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  4. EdSavoie

    EdSavoie Well-Known Member

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    The only problem i can think of with foggers on top facing down is that theit would visibly be shooting downwards as opposed to looking like a mushroom.

    Perhaps first hitting the audience with some kind of blinder (as in a nuclear explosion) first would let you get aways with a bit more :p

    Perhaps sprinkling some fake snow in the house would also complement it nicely.
     
  5. Amiers

    Amiers I wear 6 headphones. I'm that Good!!

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    Off the top of my head I would say build your mushroom cloud out of some sheer fabric that can hold the fog in it enough to keep its form yet let it out to create the look for a mushroom cloud. Mix that with lighting and I think it could work pretty well.

    I also would love to see what experiments you come up with as well.


    Other idea. would be dry ice bomb on top and gysers on the bottom a well timed together shot of both of them could give you the desired effect.

     
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  6. Jay Ashworth

    Jay Ashworth Well-Known Member

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    I concur with "physics". This will be hard for the same reasons that water effects don't scale down well for miniature moviemaking.
     
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  7. shannonlusk81

    shannonlusk81 Member

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    Hi Guys, Thank you so much for all the input and suggestions!

    A few more details: This is being used during the "opening credits" for a Zombie Burlesque show (it's okay to be a little jealous, it's pretty awesome). Our Zombies are "made" as a reaction to Nuclear Fallout, since the show is performed here in Vegas, we have a long history with Nuclear Test sites. So at the start of the show we have a fake news reel on a projector screen showing employees working at the Nuclear Test site, being productive for the war, wholesome 50's America all the way. At the end of the news reel there is a large Nuclear explosion with Mushroom cloud on screen. The following scene is the show "credits" where our zombie actors interact with a video wall behind them, essentially blending the live stage action with the screen at their back.

    My artistic director would like a transition from this "projector screen in front" to "actors with a screen behind them" and wants the projector screen to be withdrawn as the mushroom cloud forms on screen to reveal a "real" mushroom cloud on stage.

    We don't really have the space for Dry Ice during this transition (also that gets cost prohibitive when being run 6 nights a week for the foreseeable future). But I do think the rolling that dry ice naturally does would be perfect, it's a bummer it won't work for us in this instance. We also can't use any kind of structure that can't be VERY quickly struck from the stage.

    I'm leaning towards using some sort of flat horizontal surface to manipulate the top of the fog plume into a mushroom cap. We might even be able to use a performer holding some sort of signage that would then be pulled up to reveal the words "Credits" sort of like a ring girl at a boxing match? Hokey or brilliant?
     
  8. venuetech

    venuetech Well-Known Member

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    I'm thinking of that air puff gun that was a rage 10 or so years ago, airzooka . Make a larger vertical version of that device, fill it with a cold fog. Then shoot it off.
    cold fog is the key, finding the right thrust will be the challenge
    I find this is called a vortex ring gun and a common big version is made from a plastic trash can.
     
    Last edited: Jun 16, 2017
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  9. JD

    JD Well-Known Member

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    Keep it simple. Combine your fogger with a rear (or front) projection of a real blast.
     
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  10. Van

    Van CBMod CB Mods Premium Member

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    I was thinking the same thing as @venuetech. The air zooka or a facsimile can produce a smoke ring, like the smoke ring guns here:
    Me? I'd take a #5 wash tubm cut the bottom, replace the bottom with a rubber membrane, attach a pulling device, rigged to a motor or solenoid, Put a rigid cover with a big hole in it on top of the tub then duct a fog machine into the tub. Trigger the solenoid to release and you should get a be ol smoke ring. viewed front-on it's going to look like a mushroom cloud.... Or something like that.
     
  11. shannonlusk81

    shannonlusk81 Member

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    The problem here is: How would we conceal this and/or strike it quickly?
     
  12. Van

    Van CBMod CB Mods Premium Member

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    The whole thing could be built into a roll-able box or you hid it behind a ground row... Or you tell the artistic director to go into Film...
     
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  13. venuetech

    venuetech Well-Known Member

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    I was thinking that it would get vaporized by the blast. Or go with the flow and disguise it like a fat boy bomb.
    But it should be lightweight. Perhaps make like a collapsible cup. Make a trash can demonstration unit and see what can be done with that. Personally I think your director will want something that looks larger.
     
  14. Amiers

    Amiers I wear 6 headphones. I'm that Good!!

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    If this thing has to be struck fast I would drop something fabric wise from the ceiling that is shaped like a mushroom cloud , mix in lighting and shoot fog up it.

    And then as the effect is dissipating drop the fabric and strike.

    This is going to give you the biggest effect cause I also feel like he is gonna want it nuclear :0
     
  15. shannonlusk81

    shannonlusk81 Member

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    He is absolutely wanting something massive.

    I've checked the ceiling above our fogger and there's not much room for anything (We have 16 feet to the light rails and then a foot above them we have a solid grid, and the lights are densly packed on those rails so having a fabric or soft mesh piece flown in would be hard to conceal. BUT, we had a performer at one point who would be flown onstage from a platform on the side and we may be able to use that rig to fly out our Atomic Mushroom Cloud Guide, which could be kabukied offstage in a hurry via a rope.
     
  16. Amiers

    Amiers I wear 6 headphones. I'm that Good!!

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    If you can fit the effect in a 5gallon bucket then it won't take up any room and just tip the bucket effect drops and then follow the rest with a disconnect and quick strike.
     
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  17. SHCP

    SHCP Active Member

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    Have you ruled out Pyro? A flashpot seems like it would work. You need a licensed Pyro person to do the effect.
     
  18. gafftapegreenia

    gafftapegreenia CBMod CB Mods Premium Member

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    What about a different approach. A blinder light cue, a loud explosion sound cue, and some floor drying fans or other wind machine. It would "feel" like an explosion, as opposed to just looking like one.
     
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  19. JD

    JD Well-Known Member

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    Be careful what you wish for!
    Check out what smoke detectors are in use in the room, as well as any HVAC duct detectors. You wouldn't want those tripping on show night.
     
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  20. Logos

    Logos Well-Known Member

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    My lovely ex fiancee created exactly this for a shadow puppet 3D show back about 5 years. The difference was that it was for three weeks and she used a cardbard box rather than a plastic bin and operated the membrane by hand. Worked like a dream in a shadow puppet show. (Much smaller scale of course)
     
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