Your brain creates a sense of depth by combining the different perspectives from your left and
right eyes into a 'merged image'. The merged image that your brain creates has the appearance of
depth. Delivering two different views on a single screen (your TV) is a challenge.
3D viewing systems that require the viewer to wear glasses project both a left and right
image onto the same screen, and then the glasses filter out the correct image to each eye, giving
the viewer a sense of depth.
Manufacturers are just beginning to devise 3D TVs that don't require glasses, but the
technology does not yet compete with the quality and clarity of 3D systems that rely on glasses.
How are 3D images captured?
- 3D TV starts with recording content the way that our eyes see it – from two different
perspectives. Two HD cameras are used in a special camera rig to take aligned left and right images
of the chosen scene.
- The images then make their way through Sky's broadcast infrastructure where they are
anamorphically compressed and positioned side by side, in a split screen fashion, before being
encoded as a normal HD stream.
How are 3D images broadcast?
- All Sky+HD set-top boxes are capable of receiving a Sky 3D broadcast and displaying it on a 3D
TV.
How are 3D images viewed?
- Your 3D TV uses a special filter to polarize the odd and even lines of your TV picture
differently i.e. the light emitted from the odd lines is different to the light emitted from the
even lines.
- The 3D TV processes the split screen image and stretches the left image across the odd lines
and the right image across the even lines.
- The illusion is finally complete when the viewer puts on a pair of circular polarised glasses,
with the left lens blocking the light emitted on the even lines and the right lens blocking the
light emitted from the odd lines.
- There is an alternative solution known using so-called 'active glasses', where the TV rapidly
alternates a left and right image on the screen, and then the glasses use LCD shutters to ‘
black-out’ the opposite eye for each image (e.g., black-out right eye when the left eye image is
shown, then the left eye when the right eye image is shown). The shuttering occurs so rapidly that
the viewer perceives it as a seamless experience.
