Holograms: Seeing double

Holograms have come a long way since the blurry images of the 1980s – and they're letting people appear in two places at once, discovers Holly Williams

Hatsune Miku is a dream pop star. She's cute and perky, with extremely long blue pigtails; she's hit the number one spot in Japan and never hits a bum note. She won't ever cancel a gig because she's "exhausted" or get papped doing something she shouldn't – and she can even wear stockings with thigh-skimming schoolgirl skirts without anyone shrieking jailbait.

Why? Because she isn't real. She's a hologram.

Miku was first created as a piece of Vocaloid – voice meets android – technology. Powered by Yamaha and developed by Japanese company Crypton Future Media, Hatsune Miku was basically a bit of software you could buy and create pop tunes on. Real-life singing was broken down into a bank of tiny snippets of sound, that could be reassembled to create any words and phrases, letting program users type in their own lyrics and hear them sung right back at them.

It gets stranger. As the Miku program got more popular, so did the cartoon face of it: the animated avatar named Hatsune Miku. Soon, you could get a tool that allowed you to create a 3D Miku, in all her virtual glory. Events for Miku fans followed, culminating in a recent series of sell-out concerts where Miku appeared as a hologram, strutting her stuff onstage in front of crowds of excited Japanese fans. She's the biggest pop star going – and she's just a trick of the light.

It's not the first time a hologram has taken the place of the real deal: a virtual Will.i.am has duetted with an in-the-flesh Cheryl Cole onstage, while German band Tokio Hotel have done whole holographic tours. When it comes to cartoons, Gorillaz got there a while ago, appearing "live" as 3D holograms at the Grammys in 2006 – thoroughly confusing the audience by appearing to be accompanied by a real Madonna, who turned out to be just a projection too.

A British company, Musion, has also been exploring the potential of holograms. Applying recent technology to a 19th-century theatrical trick, it creates images which walk and talk in real time and have a brain-fooling, 3D appearance (the Will.i.am and Cheryl Cole performance at a German awards ceremony in January was reported in one newspaper without any mention that the Black Eyed Peas singer was an optical illusion).

So how does it work? Different companies may use slightly different systems, but Musion's director James Rock explains the company's technique. A large reflective surface is put at a 45-degree angle to a stage; historically, glass was used, but Musion has patented an "eyeliner foil", made of very tightly stretched, thin, transparent Mylar plastic. An image is then projected down on to a screen that's flat on the floor in front of the stage. The precise angle of the reflective foil means that the image appears as if on the stage. For the trick to work, the projected images have to have been filmed against a black background, and the stage must have a dark backdrop, so that the background of the projection "disappears" into the dark, leaving just the colourful hologram.

Professor John Henry Pepper came up with essentially the same trick in the 1860s – named Pepper's Ghost – but using glass. "For a large piece of glass to support its own weight on the 45-degree angle, it has to be very thick," Rock explains, "and that means you get a double image. It was called a Pepper's 'ghost' as the image wasn't very bright when using pre-electric light sources." The discovery by German inventor Uwe Maass in the early 1990s that polymer foil could be used instead, plus the advent of high-definition video and much brighter projectors, means the image no longer looks ghostly; it looks disarmingly real.

The last experience of holograms for many of us, apart from the little authenticating panels on our credit cards, was probably those novelty floating red and green 3D images around in the 1980s. So how did we get to these lifelike apparitions? Rock confesses that what I've been watching are not – technically – holograms. "We use the term 'holographic effect'. But the general public think of lots of things as holograms, and we sort of ride on the back of that. It's usually people who've seen Star Wars and Princess Leia going 'Help me, Obi-Wan' as a hologram." However, Musion isn't quite at Star Wars level yet – there is no such thing as a volumetric hologram (one you could walk around), and you have to sit face-on to see their creations.

One of its developments does have a distinctly sci-fi whiff to it, however: telepresencing. This allows you to appear as a hologram in real time, at multiple locations around the world. You can even chat to an interviewer, or take questions from an audience. The Telepresence technology relies on super-fast fibre-optic cables, which transmit the image and ensure there's no time lag (latency is a minuscule 0.2 seconds), but these are not available everywhere yet. It seems bound to take off, though: keynote speakers could address several conferences at once; those worried about carbon emissions could cut down on air miles; anyone who gets sweaty palms when facing the prospect of public speaking could deliver their speech from the safe haven of their office. Indeed, Prince Charles has already used the technology to deliver a keynote speech at the Energy Forum in Abu Dhabi, while staying in the UK and eliminating carbon footprint guilt.

So that's the tech – but what's the experience like? I have a go at becoming a hologram, and while I may be beaming into Musion's studio only from a little room upstairs one floor, I feel as excited as if I'm about to be beamed up, Star Trek-style. The reality, however, is far from that. It's a very simple set-up – I'm in a small room against a black backdrop, with panels of bright LEDs aimed at me. A small mic is looped over my ear, so I can interact with my "audience" downstairs. In front of me is a television screen, on which I can see a sort of see-through version of my holographic self on the stage, as well as the sofas facing it (where my listening – and potentially questioning – audience would be). An unobtrusive HD camera sits underneath the screen, recording me. I feel a little awkward, knowing I'm being watched in a totally different space, but at my end it's no more remarkable than the first time someone turned their camera phone on me.

Far more fun was being downstairs, watching Musion employee Jude Collins demonstrating the holographic Telepresence onstage. There she was, life-size, walking her walk, talking her talk. Her legs seemed to disappear (she was wearing black tights, but dark clothing is a no-no if you want to look like you've got a full complement of limbs), and faded in and out slightly as they tweaked the light – bright enough to appear real, but not so bright as to be luminescent.

I also have a go onstage, next to a hologram. Rock is enthusiastic about the many applications for Musion's holographic effects; one of the most popular is sure to be hologram karaoke. Forget Rock Band – this could give you the chance to duet with David Bowie, become a Beyoncé to a holographic Gaga, or Lennon to a Musion-McCartney. It's already been used at Abbaworld, where you could sing along next to cartoon versions of the Swedes.

So I take to the stage in an attempt to fill Cheryl Cole's shoes, for her duet with Will.i.am (actually, I just dawdle about feeling self-conscious and making no attempt to sing; the nation's sweetheart can rest easy). Again, the experience is much less strange when you're behind the scenes – the audience is visible through the foil, but slightly hazily as there's also a "heads-up" video display, so you can see how you and the hologram appear to the audience. This helps you to avoid sticking your arm through the hologram's face while busting out some particularly hot dance moves, which would somewhat give the game away – because you can't actually see the hologram when it appears to be standing next to you. A face-to-face meeting between me and my own hologram is, therefore, rather weirder for those sitting on the sofa than for me and my shadow onstage.

Holograms are already proving lucrative in advertising and corporate markets, and Rock even tells of some market research suggesting that 3D images are more memorable than looking at standard 2D video, because you have to use both sides of your brain. "You're processing more and hence it becomes a more memorable experience. There's a big ramification in that for advertising," Rock says.

Of course, the technology is not cheap, costing thousands or tens of thousands to hire, meaning that for a while, the technology is likely to be used mostly by big corporations, for flash entertainment, and in advertising. But with "stars" such as Miku in Japan proving the mass appeal of the unreal, and the business potential of telepresencing, a world in hologram could be closer than you think. Beam me up!