Holograms, live onstage
The image is iconic: Princess Leia, clad all in white, pleading for Obi-Wan Kenobi鈥檚 help via hologram.
Since it first appeared in 1977, this scene from 鈥�Star Wars鈥� has epitomized the idea of holographic teleconferencing.
Thirty years later, such 3-D projections have mostly remained as science fiction.
While they have been used to great effect in movies and TV shows, 3-D holograms have been too costly and too technologically complex for practical use. But that may be changing.
Projection technology has advanced to the point where it is now feasible, although still expensive, to use so-called 鈥渟tage holograms鈥� for telecommunication.
鈥淭he technology for doing this exists,鈥� says Paul Debevec, associate director of Graphics Research at the University of Southern California鈥檚 Institute for Creative Technologies in Marina del Rey, Calif. 鈥淚n the next five to 10 years, I expect some real breakthroughs.鈥�
Several celebrities have already made holographic public appearances, including Microsoft chairman Bill Gates, former vice president Al Gore, soccer star David Beckham, and Virgin Group chairman Richard Branson.
Beyond the cool factor, these holograms help the environment 鈥� a benefit regularly pointed out by those who use them.
Britain鈥檚 Prince Charles gave a speech in hologram form at a green energy conference in Abu Dhabi last year. During the prerecorded presentation, the virtual Prince of Wales stressed that, had he flown to the conference in person, he would have emitted around 15 tons of carbon dioxide.
鈥淚 am now going to vanish into thin air, leaving not a carbon footprint behind,鈥� said the prince at the end of his speech.
These onstage holographic appearances appear nearly identical to the real thing. The images are to scale. They move naturally. Only the occasional light flicker reminds the audience that they鈥檙e watching a projection. It鈥檚 far subtler than the sputtering blue and white holograms that pop up in 鈥淪tar Wars鈥� movies.
Not quite holograms
There is a slight hitch. These high-definition images may seem like holograms, but, technically speaking, they鈥檙e not. They鈥檙e more like 鈥渢wo-dimensional billboards,鈥� Mr. Debevec says.
Although they appear to be 3-D from the audience鈥檚 perspective, the images are actually as flat as a cardboard cutout.
To truly be a hologram, 鈥渄ifferent people should be able to see the image from different viewpoints and have it appear exactly like a person would appear from those angles,鈥� Debevec says.
These flat images are created by employing a modern version of a 150-year old visual trick known as 鈥淧epper鈥檚 ghost.鈥� Used by Victorian magicians to create stage illusions, the trick projects an image at a 90-degree angle onto a transparent but reflective surface, usually glass, mounted at a 45-degree angle. The result is an image that appears to be 3-D.
Telecommunications giant Cisco and the hologram wizards at Musion Systems in London updated Pepper鈥檚 ghost for the 21st century.
The new project, called On-Stage TelePresence, replaces the lights and glass with mylar screens, high-definition cameras, and fiber-optic networks. (See graphic, page 13.)
They demonstrated TelePresence in late 2007 by allowing Cisco chairman John Chambers to share a stage in Bangalore, India, with his colleague, Marthin de Beer, who was in San Jose, Calif., at the time. The two men appear to be standing side-by-side, chatting, and reacting to each other鈥檚 movements.
Ian O鈥機onnell, operations director at Musion, says that he鈥檇 like to see such stage holograms enable teachers to beam into classrooms at understaffed schools, chart-topping entertainers to perform in stadiums while simultaneously appearing in smaller venues, and mega-church pastors to preach to community congregations.
The virtual boardroom
Cisco has sold to several companies teleconferencing technology that uses hologram-like images to create virtual conference tables. Executives in two different buildings sit down at tables outfitted with high-definition cameras and monitors. The systems captures one-half of a table and streams the images into the other building.
The resulting compilation creates the illusion that the two half-tables are a whole and that all the participants are gathered in the same place.
鈥淭he principle is most similar to that of a webcam,鈥� says Mr. O鈥機onnell. 鈥淚t鈥檚 a stationary, head-and-shoulders view of people seated at a table view.鈥�
David Hsieh, Cisco鈥檚 vice president of emerging technologies, says that creating full-size 3-D images for concerts or boardrooms is possible, but complicated. The problem is science.
Light has to bounce off something in order for human eyes to see the image. Scientists have developed several workarounds to create truly 3-D images, including mist, intersecting lasers, and spinning mirrors. But these techniques are too complex for regular use, Mr. Hsieh says.
Right now, the best 3-D image you could get practically would be small 鈥� much like Princess Leia鈥檚 hologram.
鈥淚deally, what you want is a life-size image of the person you鈥檙e talking to,鈥� says Hsieh. 鈥淚t鈥檇 be a bit weird having a conference with people the size of Barbie and Ken.鈥� But, he adds, 鈥渨e firmly believe that it鈥檚 possible we鈥檒l be using full-scale, 3-D holograms in the next decade or so.鈥�
