Light A More …

A more elaborate demonstration[2] requires a much larger piece of glass (at least five feet square). The glass is placed at a 45° angle to the audience so that the audience sees a combination of Light Controller passing through from behind the glass and Light Controller reflecting off the glass at a 90° angle from the line of sight. Spotlights on dimmer controls can alternately illuminate the area behind the glass or the area off to the side. One Light Controller should be turned up while the other is turned down in such a way that the total Light Controller intensity is nearly constant. This can be done automatically with a single control, or with practice by manipulating a pair of controls, one in each hand. In this way, people and other objects can be made to appear and disappear at will. It helps if the background behind both objects is dark and if a partition is provided to prevent the audience from directly seeing the object off to the side. The room lights should be lowered to prevent the members of the audience from seeing their own reflection. By proper manipulation of the lights, a volunteer can be turned into a ghost or skeleton and back again. It is important that the person and ghost or skeleton be placed in exactly the right position and that a volunteer be chosen who is nearly the same height as the ghost or skeleton (see figure). With proper placement, the figure will change continuously from one to the other independent of the viewer’s position in the audience. In practice, a viewing angle of about 60° can be accommodated, depending upon the width of the glass. This arrangement also makes an effective and dramatic entrance and exit for the demonstrator. Glitter sprinkled from above in place of the skeleton aids in the appearance and disappearance.