Pepper Ghost Holographic Projector With Single Reflector is a mini-experiment influenced by The “Return of Tupac Shakur” performance as a result of big collaboration production between Dr. Dre’s production company and AV Concepts, which was utilizing the Musion® Eyeliner™ system in order to resurrecting the late of Tupac Shakur as a 3D Holographic projection performing on stage with hip-hop music legends Dr. Dre and Snoop Dogg at Coachella Valley Music & Arts Festival the Empire Polo Field on April 15, 2012.
Musion™’s holographic projection system is a visual platform that popularized by AV Concept in order to bring a new communication technique. It presented as a live visual performance through transforming and combining the Pepper’s Ghost optical illusion technique with an interactive 3D holographic video to develop a three-dimensional illusion that fools the audience brain into thinking the illusion image as a real figure.
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Historically, the Pepper’s Ghost is an illusion technique that was actually discovered around 16th-century by a scientist called Giambattista Della Porta on the Italian Peninsula. This illusion was re-discovered in around 1862 by British scientists Henry Dircks who try to develop the Dircksian Phantasmagoria, a version of visual effects using glass and light for established or used to make a ghost appear on-stage within the phantasmagoria performances. However, Dircks unsuccessfully to sell his idea to the theatre because it required to rebuild the theaters that too complicated and expensive. Later after John Henry Pepper joined the project, he came up with an easy way to implement Dirck’s effect on the theater performance during the production of Charles Dickens’s “The Haunted Man” in 1862. Since then, although John Pepper tries to share the credit with Hendry Dircks, this optical illusion technique became so popular to be called as “The Pepper’s Ghost“.
The Pepper Ghost illusion is a form of visual hacking trick that involves the physical phenomena created by the law of reflection principles, such as the angle of the incident ray is equal to the angle of the reflection ray when hitting a flat mirror and the behavior of light when travels to the spectator’s eyes as they view the image of a virtual object in a mirror. The appearance of the ghostly object in Pepper’s Ghost illusion is the reflection of an object hidden from the spectator’s sight of view on the plat of glass or a sheet of plexiglass that installed with a 45-degree angle and works as a mirror. Meanwhile, the transparency of glass or plastic allows the spectator to see a reflected “ghost” object while still able to watch the environment behind the transparent surface. The other keys to the trick are lighting and the design of the hidden room where the actual “ghosts” are placed, which is entirely designed as a dark room and painted black. The main concept of the room design is to absorb the light and leaving the actual “ghosts” as the only object that catches by the light and will be reflected or appear on the glass.
Today, through the development of visual media technology, the source object that reflected as the “Ghost” is replaced by high-quality video projection technology that combines motion capture technology and animation or Computer Generated Imaging (CGI), which allows people to bring the “digital doubles” of celebrities and political world leaders can be virtually projected and presented.
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Pepper’s Ghost Holographic Single Reflector Projector V.01.1 developed as the first attempt to create a holographic projector based on the John Pepper illusion scheme and the design of AV Concept installation for Tupac Shakur performance, which is made as simple as possible and easy to make with common materials.
The first illusion experiment phase is the preparation of the objects that will be reflected as “the Ghost”. The actual ghost object is an image or an animated object that designed based on the John Pepper hidden dark-room and the actual “ghosts” concept. The main objects that will be reflected or appear on the glass are made as a figure in white or bright color on the top of a black background, in order to make transparent mirror will absorb the low intensity of light from the black background and only catches or reflecting the high intensity of light from the actual “ghosts”. In the experiment, the easiest device to play or preview the image or animated object is a cellular phone, which is a quite common thing that can be owned by most people.
The second phase is the preparation of a glass or transparent device as the actual ghost image reflector. Based on the law of reflection, the object and the spectator have to be in a line and facing the mirror to make the spectator allows to see the object reflection. Therefore, the transparent mirror will be placed 45-degree facing both of the image source and the spectator’s eyes.
During the experiment, the reflector model was made with a 3 mm thick acrylic sheet, which is built as a small box construction in order to be placed on top of the smartphone and cover all the display area.
The conclusion from the first model of Pepper Ghost holographic reflector V.01 experiment is spread to various result. As expected, the Pepper Ghost holographic projection from the “ghost” image is working well, which are only the white image that successfully reflected or appeared on the screen and the black part of an image absorbed and unreflected. However, there are still notes of some problems that need to be repaired, such as:
- The position of the holographic projector that placed on top of the cell phone as image sources made some minor problem, because of the cell phone isn’t flexible and hard to be moved when needed to change the source object.
- The projection image that reflected in the transparent sheet is a mirror image of the image sources or the negative of image sources. Furthermore, to make the projection image became as same as its image sources, it needs a mirror device to make the projection appeared as same as the source. If not, the image source has to make as an Invert object.
- The acrylic thickness is made a distortion on the image projection, which is the audience eyes would be seeing the image projection became double. This happened because the screen is too thick and each of its sides projecting their own image.