Pepper's Ghost in the Ballroom
I received an email from Dustin asking,
"I am trying to figure out how the Imagineer’s got the ghosts in the ballroom to be reflected to the balcony where guests look into the room. I was hoping you could send me a side view of the ballroom showing where the glass and animatronics are placed."
The ghostly effects used in ballroom are actually an optical illusion
which was first created for stage plays about a hundred years ago. It is
called "Pepper's Ghost", named after the man who is credited with
inventing it, John Pepper.
The "real" animatronic ghost figures which you see in the ballroom are
actually performing their dances and antics above and below the balcony on
which the doombuggy is traveling. The area around the animatronic ghosts
is painted a flat black so that no light reflects off of the walls behind
them, but the ghosts are brightly lit.
Depending on the positioning, and distance the animatronics are
from the clear glass in front of the doombuggy, the reflections appear to
to be in front of the viewer, and within the ballroom in varying
If you want to see the effect for yourself, try this. Stand in a dark
room at night (make sure it is very dark outside), and while looking out
of a clear glass window shine a flashlight under your chin to illuminate
your face. You will notice that in the window your face will appear to be
floating outside. The further away you stand from the window, the further
away your floating face will appear. If you turn off the flashlight, the
face will disappear. You will see the effect even better if you get
someone else to light their face, and you look in the window.
In the ballroom the ghosts appear to vanish and reappear due to their
lights slowly turning off and on.
For more about "Pepper's Ghost" , click here to see
"Pepper's Ghost - by Rick Davis"
I hope this helps explain the effect.