3D projection - holographic projection - 3D holograms - holographic projection system
The above are all terms used to describe a Victorian theatrical effect called Pepper's Ghost. The original Pepper's ghost technique is a simple illusion which has been and is used in theatre, haunted houses, dark rides, and magic tricks. It is named after John Henry Pepper, a scientist who popularized the effect in a famed demonstration in 1862. It actually has a very long history, dating back into the 16th century when it was first observed as an unusual effect.
Below you can see how the Pepper's Ghost technique was originally used for theatrical productions in Victorian times. For the modern version of Pepper's Ghost - 3D holographic projection, please see our 3D EventPod system by clicking here
3D Holographic Projection - Pepper's Ghost
Pepper's Ghost works by reflecting the original (brightly lit) content (an actor dressed as a ghost - see above) through an upbacked mirror. It's like looking out of a window at nightime. You see yourself as a reflection from the window and the view out of the window. The reflection can look 3D and very real if the illusion is produced well. In Victorian days, the audience would often pay to just see the ghost (holographic type effect) on stage! There is no doubt that the Pepper's Ghost effect can be a visually powerful effect when produced correctly.
By producing digital content and using a video projector or LED panels (or a display monitor for smaller systems), it is possible to "3D project" real video footage of products, life sized or bigger than life sized people, creatures and any sort of content when using computer graphic imagery (CGI).
The projection looks very much like a "holographic type effect" but it should be noted that the Pepper's ghost technique is not a real hologram in the true sense of the word but the effect certainly does look "holographic".
The word hologram has now become a generic term for pretty much anything 3D, but a real hologram has parallax (http://en.wikipedia.org/wiki/Parallax) so you can actually look around the 3D image.
With Pepper's Ghost, eventhough it looks 3D, there is no real 3D and no parallax, as the original content comes from 2D source such as a video projector.
With modern Pepper's Ghost productions, it is possible to mix the real with the virtual, i.e. real presentors and real objects with the holographic type effects. This works well for musuem projects and stage based events. Please see the video below which features a "live" presentor talking to the audience and video "holographic type" content
With the modern use of the Pepper's Ghost technique, the original content is digital, i.e. from a video projector, so the holographic type effect can be manipulated using various interactive techniques such as an Xbox one Kinect ("AirTouch") type controller. You can see an example of "AirTouch" control in the video below
Given that the original Pepper's Ghost was a Victorian theatrical illusion, the original patent for the effect has long since lapsed. This means anybody can make a Pepper's Ghost using an unbacked glass or plastic mirror. For small scale Pepper's Ghost illusions, glass or plastic is fine and easy to work with. However, large sheets of glass for large scale Pepper's Ghost projects are hard to handle so modern versions of Pepper's Ghost use a special foil mirror for the effect. The foil can be rolled up for transport and ease of installation. For the foil mirror to work, it must be held flat and at approx. 45 degrees
The foil version of Pepper's Ghost has been patented by various companies. Most of the various modern patents relate to how to hold the foil mirror flat and at approx. 45 degrees (required for the effect to work without you seeing the foil mirror, i.e. you look through the foil to see the reflected "holographic type effect")
iC3DsFX offers a foil version of the Pepper's Ghost effect which is backed by a patent. This patented version of the technique allows for limited reuse of the "special foil" when it is used for multiple events. This keeps the costs down as the foil is expensive to replace
It should be noted that other companies using foil for their Pepper's Ghost system can not reuse the foil per event. This is due to the way they hold the foil flat and at 45 degrees by deploying a rachet strap solution. With ratchet straps, the foil is damaged when taken down for the next event. The special foil is optically clear (transparent) and acts as a mirror, reflecting the original specially produced digital (so called hologram) content
Therefore for large scale Pepper's Ghost project we can offer a lower cost solution, especially for multiple usage events and permanent installations. Please see our "3D EventPod page" for further examples of various Pepper's Ghost projects
To see our FXimagePod, a smaller Pepper's Ghost, 3D projection system, please click here