Edge article about a potential successor to the current stereoscopic 3D (with or without glasses), fixing its annoying problem that depth focus does not match angular focus.
SeeReal’s new system would track eye movements with a camera and then modulate a display to emit the correct wave lengths to an observer’s eyes so that holographic images appear with matching angular and depth information, as a real object would. The improvement over traditional holography is the eye tracking system which allows the projector to cut out all image information that the observer would not currently see anyway.
Holography has been around for 60 or 65 years, but has always been based on high-resolution emulsion films,” says Stolle. “It requires a very high-resolution medium – on film it’s easy, but on a display, to create a decent angle, I would need pixels of less than one micron in size! Which means I’d end up with more than 250,000 times HD resolution if I wanted to follow the classic approach to holography – which is why nobody has bothered! I’d have to compute every single one of those pixels at 60 frames a second. Nobody had a solution to do this practically. But if you look at the information this [imaginary super display] is creating, a lot of it is stuff you won’t see. The only stuff you’ll see is that which goes into your eyes – and that was our starting point. We only create the information an individual will see – which we can do because we know where the eyes are. So we can use a normal LCD to create a hologram, as long as we limit the information.”
They’ve got a single-viewer prototype rigged up, based on medical imaging equipment, which is still rather flickery and limited in permissible head movements, but already very convincing in its image quality.
Nonetheless, the presentation of 3D is genuinely startling – sufficient for us to reassess our stance on 3D entirely. We’re able to toy with a 3D model of a spaceship, using a trackball to rotate it and move it closer and farther away – we can push it far into the distance beyond the screen, and drag it out of the display until it sits inches from our face. At all points it feels like a natural, physical object that we could reach out and hold – albeit a luminescent red one. Later, we’re shown a tank full of water, its length tapering away from us, which see-saws forward and back. The illusion of a physical object is extremely convincing.
We also watch some colour animations that extend into the screen and note that we can focus on elements within the image as we please. With holography, the entire object is presented as it is in reality, and the viewer chooses which bit to focus on – look at the foreground and the background blurs as it would when you look at a real vista, and vice versa. This necessitates some changes in the language used by cinematographers, who are accustomed to drawing the viewer’s eye with a shallow depth of field – ie, by blurring out all but one element of an image.
An interesting point: if this technology were implemented for movies, directors would have to relearn their craft – it’s like filming a theater play.
Felix Forrest, a steadicam operator and director of photography, is one convert. “I am a big fan of cinematography and I have an absolute fear of and hatred for stereoscopic 3D because I think it destroys a lot of the artform,” he says. “That’s the position I started from. Then I sat down at the first [SeeReal] demonstration and thought: ‘I’ve got to change the way I shoot things’. I think we’ll end up going back to some of the more traditional techniques like you would see with film noir, where you use light and shadow to draw your attention to things. It’s a bit like lighting for theatre.”
So too will cinematographers grapple with a changing sense of scale: when viewers are aware of being in a perspective relationship with a scene, it can be difficult to escape the impression of viewing a tiny diorama. And, although SeeReal’s representatives say this is far less of an issue with holographic 3D than it is with stereoscopic 3D, quick cuts are also difficult to make, as the eye will be fatigued by rapid changes in focus. “It changes the pace at which you can tell a story,” explains Forrest. “Action films become quite difficult – you can’t do a lot of handheld camera work, so you lose a lot of the frenetic pace.”