Help with making a simple electric movie prop.

Discussion in 'Homework Help' started by jbraney97, Sep 6, 2015.

  1. jbraney97

    Thread Starter New Member

    Sep 6, 2015
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    Hello. I am making a movie for a college project. In one scene, someone fires a machine gun in an almost pitch black room. What I want is a really cool effect where the only visibility the camera gets is the muzzle flashes from the machine gun, lighting up the room and people's faces.

    This is almost impossible to do properly with special effects alone, so I thought of a simple contraption I could build that would solve the problem. The only thing is that I know what I want to get for the parts, but I don't know what the parts are called for me to order them. I was hoping you people could help me out with the names for the objects I thought of, if they exist, and give me any advice on the build if you think there is an easier way of doing it.

    The gun is a high quality airsoft rifle, and the barrel has 5 openings. The obvious one is the part the bullets come from, and then there are 4 barrel ports by the front. If this were a real gun, then the flash would come from the front end mainly, but would also cast light from each port.

    What I want to do is put a small, but powerful (as powerful as possible for a small enough size, help me out here!) LED light bulb in each port, and wire them to the side of the gun, where they will all connect to a device, which is then hooked up to a battery. My main problem is figuring out what this device is called, so i will describe it to you. I need some small box, or computer chip-looking card which can receive the LED lights' wires on one end, and battery power from the other. The little device would have some switch, slider, or series of buttons on it to repeat the battery signal. Thus, instead of powering on the device and having the orange LEDs stay on, I could set it to the right tempo, and have them flash at the speed of automatic fire. This would create the right orange lighting and cast the right shadows, and enable me to add muzzle flash special effects afterwards.

    Please let me know if I need to clarify anything. I really don't know what these parts are called, or how exactly I would set them up. Thank you SOOO much for your help!
     
  2. nerdegutta

    Moderator

    Dec 15, 2009
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    785
    Hi, welcome to the forum.

    I see at least two ways of doing this.

    #1
    Use a 555-ic timer, and a 4017-ic counter/divider. Like this:



    #2
    Use a microcontroller. And program it to light the LED in the sequence you need.


    Do you have some pictures of the "gun"?
     
  3. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,393
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    Probably easier to steal some night firing footage from some youtube video and then splice in the illuminated faces.
     
  4. WBahn

    Moderator

    Mar 31, 2012
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    I doubt that the LEDs will give you the effect you are looking for. Does the flash from a strobe light look like the muzzle flash from a cannon? Not even close. But, that's not to say that it might not be close enough for your purposes (audiences accept as "real" all kinds of things that aren't even close).

    One option to explore, particularly if you only have one scene where this is needed, would be to contact some of the local gun ranges (if you have any) and talk to the owner and describe what you are trying to achieve. They may know someone that has a suitable weapon and blanks and would be willing to get together with you to help you film the scene. You might also contact some studios, including the big guys like NCIS and such, and ask them for advice. I suspect at least some of them will be willing to offer useful suggestions to students trying to learn the craft.
     
  5. nerdegutta

    Moderator

    Dec 15, 2009
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    I agree on the LEDs, they might look like a toy in your film.

    How about 10w white bright LED? One flash of those in a dark room might be what you are looking for. Perhaps it will only look like a flash from a camera, and it will only look stupid. :)

    With the 10w LEDs you might get a problem with space, since they are quite big. And heating. If they are on for a long time they get really hot.
     
  6. WBahn

    Moderator

    Mar 31, 2012
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    If the effect is only lighting up other objects (i.e., if the muzzle flash itself is not to be in frame), then a strobe light behind a colored filter might work the best -- and the details of the weapon having a muzzle brake is immaterial unless you are really trying to draw attention to the fine details. But if the muzzle flash IS going to be in frame, then it will not look realistic using lights because a real muzzle flash is due to flame the physically exits the ports and exists in 3D space.
     
  7. jbraney97

    Thread Starter New Member

    Sep 6, 2015
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    0
    Really, I just need it to light up the room. If it is white, then that would work. I need to light the room in a way similar to a real gun, I.E. I can't just turn on and off the light. I can then later go into the effects and make the light the right color, tone it down, turn it up, I just need light to even be able to work with the scene.

    The gun is an M4 Assault Rifle. I only thought about LEDs because I know they can be really strong, but you are probably right about the strength of the light. Is it possible to find a bright but small light that could possibly just protrude from the barrel?

    The plan is to use the lights as a way of creating light to work with. I can change the color, brightness, and flame-look in Adobe After Effects. Besides, I will add the muzzle flash in on top of the light bulbs, so that you don't even see them in the finished project. Ultimately this means that the muzzle flash will be added with special effects, but the room will light up as if it was done by a real gun.

    [The gun is also life-sized, except for the barrel, since it is a high quality airsoft gun. The internal barrel diameter is 6mm.]

    Even if it is a single lightbulb that just protrudes from the barrel, that would be enough. If it did protrude, it would help if it was somewhat narrow, so it didn'g look like a big ball at the end of the gun. Maybe something with this general shape:

    http://image.lampsplus.com/is/image/4C116.fpx?qlt=65&wid=236&hei=236&fmt=jpeg
     
  8. jbraney97

    Thread Starter New Member

    Sep 6, 2015
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    0
    Also, I forgot to say thank you to all of you. Your suggestions are excellent, and I am really excited by how quickly so many people posted here!
     
  9. WBahn

    Moderator

    Mar 31, 2012
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    Then you might do well just to use a neon strobe light. The bulbs can be pretty small and they can put out a lot of light. You can probably find a suitable controller someplace and just rig something to remotely mount the bulb to the barrel.
     
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