Phantasmagoria’s future: how to build a ghost

It was in the midst of the blood-drenched upheaval of the French Revolution that horror shows bewitched the public. In Paris in 1797, the Belgian physicist and showman Etienne-Gaspard Robert (better known by his stage name, Robertson) presented his first phantasmagoria. Parisians flocked to enter rooms full of haze – some suggest hallucinogens – to be assailed by looming ghosts, skeletons and recent high-profile casualties of the Revolution. These hand-painted ghouls were projected onto smoke and accompanied by screams, cackles and sounds of thunder.

The phantasmagoria was made possible thanks to the invention of the magic lantern, an early image-projection technology which was the public visual medium of its age, until it was surpassed by the slide projector.

“Suddenly you could go anywhere in the world, you could go into space, you could see your favourite literature portrayed on screen, or you could watch horror shows,” says Terry Borton, who reproduces authentic historic shows with the American Magic-Lantern Theater. Phantasmagoria shows attracted both punters in search of a thrill (the 18th-century equivalent of a horror film date night) and people who sincerely believed they were witnessing paranormal phenomena, enthusiastically encouraged by Robertson.

“The advent of every new technology claims to have shown ghosts, [not just] the phantasmagoria,” says Professor Vanessa Toulmin, an expert in Victorian entertainment based at the University of Sheffield. “Photography very quickly got spiritualists photographing ghosts; even early film captured ghosts, so new technology and ghostly apparitions go together.”

Despite the exploitation of the magic lantern by bogus spiritualists, its origin was strictly scientific, having been invented by Christiaan Huygens, a founder of mathematical physics. It was within similarly scientific circles that the most famous and enduring ghost illusion was conceived.

The ghost illusion was described as early as 1584 by Giambattista della Porta in his ‘Magia Naturalis’ – in which he explained how to use reflections in polished glass to “see in a room things that are not” – but it was popularised by the chemist and director of the Royal Polytechnic Institution Professor John Henry Pepper. In spite of the contributions of other scientists and engineers, the illusion became popularly known as Pepper’s ghost.

The illusion works using a light source and a sheet of glass (or another transparent, reflective surface); this sheet is tilted at 45° between the viewer and the stage, while an actor portraying the ghost stands hidden below the stage. When the actor is illuminated, light is reflected from them to the glass. Some light is reflected from the glass towards the audience, while light from the rest of the stage passes through the glass to reach the audience. This gives the appearance of a translucent, ghostly figure standing amid the action on stage.

‘I think illusion is a branch of science and technology because the very people who invented illusions were scientists and engineers. It’s all about the engineering.’

Pepper’s ghost proved a hit in plays and magic shows – first appearing on stage in an 1862 production of Charles Dickens’ ‘The Haunted Man’ – but also in the scientific community, with Pepper giving regular lectures exhibiting and explaining the effect. The effect was said to have captivated and confused fellow scientific heavyweights, including physicist Michael Faraday.

“I think illusion is a branch of science and technology because the very people who invented illusions were scientists and engineers,” says Toulmin. “It’s all about the engineering.”

While the magic lanterns used by Robertson to terrify Paris have since been replaced with digital projectors, Pepper’s ghost has not been surpassed and continued to be reinvented throughout the 20th century. The emergence of amusement parks in the second half of the 20th century scaled up and automated ghostly illusions, bringing them to dark rides and other immersive attractions. Most notably, The Walt Disney Company recruited large teams of engineers to ensure that its ambitious new theme parks would feature genuinely innovative spectacles.

The Haunted Mansion, which opened at Disneyland in 1969, features one of the first public demonstrations of video projection onto a 3D surface to make stone busts appear to sing, and is populated with audio-animatronics, Disney-patented robots, which are programmed to move while singing, speaking or making other noises. Perhaps the world’s most famous ghostly installation is the Haunted Mansion’s ballroom. This employed the Pepper’s ghost illusion on a record-breakingly large scale and in combination with animatronics: the 27m-long, 9m-high scene is populated with the reflections of ballroom-dancing robots in period dress.

Several years ago, Matt Ford, Emmy-winning lighting designer and president of Magic Lantern Creations, set out with his wife to transform their Los Angeles home into the House at Haunted Hill. The annual attraction may be modest in size, but its high-tech effects rival those at Disney parks. Ford pulled together a group of showbiz contacts willing to offer their expertise – including veteran theme park voice artist Corey Burton and actor Neil Patrick Harris – to build a sophisticated haunted house which presented a story, rather than merely playing host to unrelated spooky events.

“What’s unique about our show is that it’s an actual show and that requires very specific things to happen at specific moments in time,” says Ford. “If the technology did not exist for us to make all of this happen at specific times, we could not have written the show the way it was.”

An Alcorn McBride V16 Pro show control system (identical to those used in theme parks to connect and operate multiple control systems) made the narrative possible. The V16 precisely coordinates the show according to SMPTE time code – a set of cooperating standards to label individual frames of film with a timecode defined by the Society of Motion Picture and Television Engineers – triggering events at specified points in the story indicated by the ticking code. These include music, voices, movements, sound effects, lighting effects, front projection, projection mapping, Pepper’s ghost effects and even a speaking face precisely projected onto a moving tombstone, which gives the impression of a complex animatronic.

“Pepper’s ghost goes back to the 1800s, the projection mapping was very innovative at the time and the equipment that we use to execute the illusions is very high-​tech; we’re using a lot of the same equipment that is used at Disneyland,” says Ford. “I guess the illusions themselves are not very high-tech but the way that we execute them and make them behave is innovative.”

Mention of Pepper’s ghost may trigger quaint ideas of a live actor beneath a Victorian stage, perhaps draped in a white sheet. However, 21st-century advances in digital technology allow the illusion to expand beyond the niche fake-ghost industry. The most high-profile use of Pepper’s ghost in recent years was not a macabre showpiece but the centrepiece of a music festival.

At the Coachella Valley Music and Arts Festival 2012, the rapper Tupac Shakur appeared on stage and greeted his audience: “What the f@!k is up, Coachella?” he hollered. The real Tupac was murdered in a drive-by shooting years before Coachella was founded, but this Tupac was undeterred by the inconvenience of being dead, performing a song the real Tupac never performed in public, teaming up with a live rapper for a duet, then evaporating into thin air. While it was widely described as a “hologram”, it was, in fact, a Pepper’s ghost. The lifelike figure was conjured up using a taut foil to reflect HD video footage, which had been painstaking rendered by visual effects company Digital Domain and projected onto a reflective surface at the front of the stage.

“There’s no new technology that surpasses [Pepper’s ghost]; if you want to put something up on a stage there is no other real way of doing that apart from Pepper’s ghost,” says Darren Hendler, head of digital humans at Digital Domain. “The technology behind the projection has come pretty far, and even the screen materials have come pretty far, but there’s no other way of projecting and creating an image floating in space on that stage.”

Coachella was the ideal place for the illusion as the audience stood directly below and in front of the stage and the significant distance between projection and audience made the ghost of Tupac appear less conspicuously flat. According to Ian O’Connell, director of events at Musion (which holds patents for these high-definition Pepper’s ghost projection systems), being able to project in HD while holding the foil under great tension allows for far more lifelike projections and larger, clearer displays.

Since Tupac’s appearance at Coachella, the ghosts of Michael Jackson, Teresa Teng and other deceased artists have been summoned for novelty performances, echoing the resurrection of deceased French Revolutionary figures in phantasmagoria.

Hendler believes that, soon, these sophisticated Pepper’s ghosts could be combined with video-rendering software to create more spontaneous performances. Rather than preparing footage months before, a live performance double could have the face of the deceased celebrity rendered onto theirs, making it appear that the deceased celebrity is on stage interacting with the audience. According to Hendler, it won’t be long before the facial rendering can occur quickly and reliably enough to produce a photorealistic digital human. These digital characters could take on the appearance not just of other people but of anything remotely humanoid, opening up the possibility for performers to shapeshift through hundreds of forms during a concert.

“I would say that by early next year we will probably start to see realistic virtual characters appearing with high-fidelity facial performances where they’re actually emoting and talking pretty realistically, and then probably by the end of next year, maybe the following year... you’ll start to see live digital human performances that are trying to pass themselves off as real humans. I think some of these first versions look pretty creepy and unnerving but it’ll get there very quickly,” he says. Hendler acknowledges that this possibility raises ethical questions about what is appropriate to do with a dead person’s perfect likeness.

“When musicians died and they posthumously released albums there was an outcry, but we slowly got used to that,” he says. “So we’ll see if we get used to this technology.”

The magic lantern was the centrepiece of phantasmagoria, while Pepper’s ghost was such a mainstay of Victorian theatre that many venues had dedicated areas under the stage for the illusion. It is conceivable that, in the near future, entire shows could be designed as vehicles for resurrecting dead celebrities or metamorphosing performers using Pepper’s ghost. There is a risk that, in some cases, these high-tech illusions could intrude on design and storytelling.

“That’s a big difference between just demonstrating Pepper’s ghost, which is what Pepper did, and incorporating it into a story. In order to do really full-on ghost effects, you actually need to design them before you’ve designed the rest of the show because they are very sightline-specific and material-specific,” says Paul Kieve, a professional illusionist who designs effects for stage and screen.

“In ‘Ghost’ [the Broadway Musical], the designer Rob Howell had to take the results of my workshops and design a whole musical around it, which was an extremely difficult process. You can’t just slap these things in.”

Technological advances have allowed Pepper’s ghost to be reinvented and could inspire the development of whole new forms of entertainment. However, the principles on which Pepper’s ghost is conjured remain unchanged over the centuries, as have the basic principles of what makes a great show.

“Ghosts and ghost stories really need to engage the audience’s imagination in order to be successful. You can have all the technology in the world [...] but theatre is always going to play on imagination,” Kieve adds. “I am really interested in technology and try to keep up with it but sometimes the really successful things are the ones that could have been done 100 years ago.”