Television is one of the most dynamic industries in terms of technical innovation. The popularity and ubiquity of TV as an entertainment option means that television companies are constantly looking for ways to improve and enhance the viewer’s experience.
It was seen in the invention of cable and satellite television, widescreen TVs and the ability to record, pause and re-watch live transmissions. The latest innovation is 3D television. Here’s the lowdown on this latest addition to the TV-watching experience.
What is 3D television?
Simply put, it is television that gives the illusion of a third dimension – depth – in addition to the two dimensions of height and width that current television sets provide. This means that images on the screen can appear to be ‘reaching out’ from the screen towards the viewer or to appear in the air around them. The technology to produce this effect has been used in cinemas for some years, but is now making its way into home entertainment systems.
How does it work?
When our eyes look at an object, the brain takes the image that each eye perceives and combines them into a single visual image. This helps us calculate distance and so perceive depth. Three dimensional television works in a similar way, by projecting two separate images onto the screen, one for each eye. The glasses that the viewer needs to watch 3D content merge these images together for the brain, resulting in an illusion of depth.
The glasses that come with 3D television sets are the key to having the three-dimensional experience. In the past, in 3D cinemas for example, the glasses came with colour filters so that each eye only saw the image intended for it. They had a red lens and a blue lens. The eye behind the red lens would only see the blue images, and vice versa. Because the focal point is the same for both images (the screen) the brain thinks you are looking at just one image, giving the sense of three dimensions.
Modern glasses that come with 3D televisions operate slightly differently. Their lenses block alternate images (rather than filtering parts of the spectrum). When an image intended for the left eye is shown on the 3D television, the glasses block the right eye, and vice versa. Because the images are displayed in such rapid succession from the right to the left eye, your brain still thinks you are seeing one picture, creating the impression of depth.
Stereoscopic technology is not actually a new invention. Sir Charles Wheatstone, who constructed an apparatus to view a photograph with a three-dimensional effect, first developed it in 1838. The concept gained public exposure when it was used to ‘animate’ a photograph of Queen Victoria at the Great Exhibition of 1851 in London.
The first movie in 3D was shown to the public in 1922, while the technology was first adapted for television in 1928 by television pioneer John Logie Baird. Using 3D in cinemas proved popular in the 1950s and 1960s, particular;y in America and Russia. However, the technology was simply too expensive to be used for normal home television sets and it is only with recent advances in digital technology that the potential for three-dimensional television in homes has become feasible.
Can anyone have a 3D television?
Most people can enjoy the 3D television experience. However, there are some individuals – possibly between four and seven per cent of the population, who have a condition known as ‘stereo blindness’. This means that they are unable to perceive the dimension of depth. They can still watch the same programs but will need to wear the glasses and the content will only appear to them as a 2D program.
Do I need a new TV set?
To experience TV in 3D you will need to purchase a television that is designed to play 3D content. And you will need a pair of glasses to enable you to see said content. However, you do not need to have two television sets as 3D televisions can still play traditional 2D content.
So the three things you need for to experience 3D TV are:
• A television set designed for 3D
• Content that has been formatted for 3D
• A pair of glasses to enable you to see the 3D effect
Modern 3D televisions build on previous technological advances in the televisual sciences, notably high definition. Previously, the requirement of high definition and its relative expense meant that three-dimensional technology was only employed in cinemas where economies of scale made it cost effective. But now that high definition screens are a part of many new TV sets, the 3D technology can align with it so making 3D TV much more economical in the home environment.