With the right kit, you can play
games, watch Blu-ray movies, view photos and even surf some websites in 3D.
Getting 3D on your PC might sound
expensive, but there are plenty of ways in which you can experience it on your
current machine at little or no cost.
Most modern computers are capable of
generating a 3D image; it’s the display hardware you’re probably lacking, and
this is where things can get expensive. 3D monitors start at around $225 for a
22in screen; 3D laptops such as the HP Envy 17-1195EA and the glasses-free
Toshiba Satellite P855-10G cost more than $1,500; 3D projectors are also in the
$1500-plus price range. Chances are, though, you already have a means of
displaying 3D images, without buying any new tech.
It’s estimates that between 17- and 50
percent of us will own a 3D ready TV by 2016, and many of us already do so –
even if it didn’t come with a pair of the special glasses that are required to
enjoy the 3D effect. If you’re planning to buy a new TV and will be spending
more than $675, you’ll likely find it supports 3D as standard.
Nearly
17 per cent of homes will have a 3D ready television by 2016
Even if you have no dedicated 3D hardware,
you can still join the 3D revolution. The results might not be as good as they
are with a stereoscopic monitor or TV, but we’ll see how you can enjoy 3D
content on an ordinary monitor. We’ll also show you how to create your own 3D
content using nothing more than a digital camera and a cheap piece of hardware
you can make yourself.
3D images aren’t viewable only onscreen;
the effect can also be created on the printed page. We’ll show you how to
produce 3D prints from your own home printer or an online printing service.
What do we mean by 3D?
Graphics-card manufactures have been
claiming for years that their products provide 3D graphics, but this they
simply mean that the graphics card has sufficient processing power to render a
3D scene in an almost photo-realistic way.
And by its very definition, any camera that
has ever existed has been able to create a photo-realistic image. Be it a
graphics card a camera or a TV, many of the standard non-3D gadgets we already
own are able to reproduce many of the attributes of the real world that we use
to judge depth.
Such attributes are perspective, a
reduction in the intensity of colour with distance, the way in which nearby
objects can partially obscure more distant ones, shading and shadows. However,
one important factor is missing: binocular disparity.
Binocular disparity occurs because we look
at the real world from two perspectives – with our right- and left eyes – and
our brain merges them into one. only stereoscopic display systems can replicate
this effect to offer what we now refer to as true 3D.
Stereoscopic-imaging systems must either
generate or record two slightly different images, then provide a means of
viewing so that each eye sees a different image.
A stereoscopic image is what most people
think of as proper 3D but, even here, some elements of the real world that we
use to recognize depth are not present. One such element is motion parallax;
you’ll notice it as you move your head to the left and right. The closer an
object is to you, the more it appears to move with respect to more distant
objects.
Then there’s something known as
accommodation, which is the technical term for the way we are able to focus on
objects at certain distances, while rendering closet and more distant objects
out of focus. The science of holography is able to reproduce these and any
other imaginable ways in which humans see in 3D.
Holographic displays are in production, but
they’re far from becoming commercial products. Given that the first
photographic hologram was produced in 1962 and you still can’t buy a mainstream
holographic camera, holographic graphics cards and monitors might be some way
off yet.
How 3D displays work
Active
displays work by displaying left and right images alternately, and must be used
with glasses containing electronics
Passive
displays work by displaying left and right images in alternate stripes, and
must be used with polarised glasses
You
can view Earth’s Street View in 3D, even on an ordinary monitor
It isn’t difficult to appreciate how a
camera with two lenses is able to record the two images necessary for
stereoscopic display. Similarly, the software required to render a scene could
be designed do so from two slightly different viewpoints.
It’s equally easy to appreciate that the
only real constraint on the processing of a stereoscopic pair of images is
sufficient power. A CPU has to process both images in the same time that would
normally be required to manipulate a single image. For video in the UK, that
means a minimum of 25 pairs of images per second.
What’s much more difficult is designing a
viewing system that ensures each eye sees only one of those two images. Over
the years, countless types of stereoscopic display have been devised – we’ll
see some of these later in this feature when we turn our attention to viewing
3D images on an ordinary monitor. First, though, we’ll look at the three
methods that are currently used on most 3D monitors, laptops and televisions.
The most common 3D technology is active
display, and to appreciate the effect you must wear glasses that contain active
electronic circuitry. Left and right images are displayed one at a time, with
the hardware swapping between them in quick succession. Clever electronics
automatically switch each lens from opaque to transparent when the image
intended for that eye is on display.
For the technology to work smoothly, the
display must reveal two frames in the same time it would usually show just one.
returning to our UK example, the display would have to show 50 rather than 25
images per second.
The next most common 3D technology is the
passive display. Rather than interleaving two images in time, they’re
interleaved in space. In other words, a single image is composed of horizontal
lines from both the left and right stereo images, which are displayed
alternatively down the screen.
Immediately in front of the screen’s LCD
panel is a polarizing filter. This is made up from alternate horizontal strips
of right and left hand polarizing material, which line up with the horizontal
stripes of the image. This means the stripes in one of the images becomes
left-polarised, and those in the other are right polarised. The passive 3D
glasses used with this sort of display also contain left- and right hand
polarising filters, with one over each eye. These don’t contain any electronic
circuitry.
A left-polarising filter will allow left-
but not right polarised light to pass, and vice versa. This ensures that each
eye is able to see only the image intended for it.
The drawback of this method is that the
horizontal resolution is halved: a full-HD screen using passive 3D can show
only 540 lines from each 1920x1080-pixel image.
It’s possible that a better-equipped
monitor with twice the vertical resolution could overcome this limitation, but
none exist in the shops today.
On the plus side, passive glasses are far
less expensive than active ones, which cost upwards of $75 per pair. They are
also slimmer and lighter, making them more comfortable to wear.
A third technology, which is surely going
to become more popular in future, is the auto-stereoscopic screen. This is
otherwise known as ‘glasses free 3D’, and means no viewing aid is required to
enjoy the 3D experience. You are potentially able to watch 3D content with
friends, without forking out for additional pairs of specialist, and without
anyone worrying about how they look.
As with passive 3D displays, the two images
intended for the left and right eye are interleaved in the form of thin
stripes. In this cases, however, they are vertical stripes.
Rather than placing a polarizing filter
over the panel, auto-stereoscopic displays use a lenticular sheet. This is
comprised of thin vertical cylindrical lenses, which cause the alternative
stripes of the two images to be directed left and right toward the eye for
which they are intended.
Apart from the halving of the vertical
resolution, the main disadvantage of this technology is narrow viewing angles.
For a TV that’s going to be viewed by several people this is a show-stopper.
Lenticular monitors and laptops are available to buy now.
