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                    How
        Laser Shows Work - Outboard Equipment 
              
                                    It takes more than the
        laser, projector, console and graphics system to present a spectacular
        laser show.  Laserists need smoke machines, fiber optic beam
        delivery systems and other outboard equipment. 
                    
                                Smoke Machines 
                                  
                                A "hazer" type smoke machine
        that makes very fine particles -
        Photo courtesy of MDG 
              
                                    One of the most important pieces of
        outboard equipment (for laser beam displays) is the smoke
        machine.  Since light itself is invisible, the eye only
        sees the reflection of light from objects and surfaces,
        laserists need to put particulate matter (haze or smoke)
        into the air to make the laser beams visible.  The fine
        particles from the smoke machine deflect the light from
        the laser towards your eye so you can see the beam
        effects in the air. 
          The two most common types of smoke machine in use are
      "water based" machines and "hazers".  Water based
      smoke machines use a water based fluid that is pumped through a heated
      evaporation chamber.  They typically produce dense clouds of large
      particles which do not remain suspended in the air for long. 
          Hazers typically use an oil based fluid that is forced
      at very high pressure through a very fine nozzle to "crack" the
      fluid into ultra fine droplets.  Hazers produce a very fine haze that
      is often invisible to the eye but which makes lots of microscopic
      particles which remain suspended on the air for a long time and reflect the light
      from the laser beams towards your eyes. 
                    
                                  
              
                                Fiber Optics 
                                    Laser light shows may make use of
        fiber optics to transmit the laser beam from the laser
        system to the projector or (more often) from the
        projector to a remote scan head. The hair-thin glass fiber acts as a
        "pipe" to transmit the light from the input coupler, through
        the fiber, to the output colliminator. 
            'Side Glow' fiber  is a thicker type of fiber
        optic that has no jacketing surrounding it.  The light in the fiber
        can escape out the sides so can
        also be used as a special effect where hair-thin,
        glowing, lines of light are required; such as for product outlines or as
        signage. 
                    
                                  
                                
        Coupler, fiber optic and output colliminator
      - Photo courtesy of new Method Lasers 
                                  
              
                                Add-on Effects  
                                  Laser light shows make use of effects
        such as bounce mirrors, mirror balls, spinning
        diffraction gratings, remote servo controller mirrors and
        other effects to manipulate and re-direct the beams
        projected from the laser projector.  By using bounce mirrors, the
      beams are reflected around the venue creating the illusion that there are
      more beams in the space. 
                    
                                
                                  
                                    
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                                        | An array of bounce
              mirrors hanging from a pipe (the mirrors are turned away from the
              camera as this photo was taken during set-up) | 
                                       
                                     
                                   
              
                                   
          There are also add-on electronic devices used with
      laser systems such as geometric correctors which can remove distortions in
                                  the laser image caused by off-axis
                                  projection  or projecting onto onto
                                  uneven surfaces, 360 degree projectors which
                                  allows for the projection of the images at
                                  many points around the venue rather than in
                                  just one location, digital colour decoders, time code
                                  synchronisers to synchronize laser effects to
                                  video, and laser show storage systems. 
                    
                                    
                                  ADAT-XT recorder
      - Photo courtesy of Pangolin 
              
                                   
         One of the most commonly used add-on devices is the ADAT
      recorder.  Originally designed as an 8 track digital audio recorder
      for small studios, it can be modified to record laser signals.  Audio
      signals occupy a spectrum from 20 Hz to 20 KHz while laser signals are
      from 0 Hz (DC) to about 10 KHz.  The CADA-MOD board by Pangolin Laser
      Systems conditions the laser signals and modifies the ADAT recorder so
      that X, Y, R, G, B, a control signal and left and right audio can be
      recoded onto tape.  By recording a show on tape, it can be reproduced
      exactly the same every time or can be sent to other locations or even
      other countries for playback. 
                                  [
                                Laser 
          and exciter | Projector  
          | Scanners | Control 
          console | Graphics system 
          | Outboard Equipment ]
              
                      
              
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