Your brain creates a sense of depth in real life that gives depth perception and hence a 'real life image'. 3D Movies and TV images are created and can be used with 3D Glasses to fool the brain into thinking it's seeing a 'real life image'.
3D movies and TV broadcasts project a left and right image simultaneously onto the same screen, and then the glasses that you wear filter out the correct image to each eye, to create the sense of depth of a 'real life image'.
How is a 3D movie or TV Program filmed?
A 3D moving image begins by recording the way that our eyes see (from two different perspectives). Two HD cameras are used in a special camera apparatus to take left and right images of the chosen scene or subjects. What you then see is exactly what the camera operator views.
If the camera shots are set up with a 3D audience in mind, you can enable recording of the actual 'real life image' experience. If the camera operator is behind the goal of a football match or falling through the air with sky-divers in a movie, then the viewer at home or in the cinema can have almost the same experience.
Each image is then recorded sequentially (left and then right image) and can be broadcast live or saved for future broadcast.
How can I view 3D Moving Images?
There are two different 3D TV technologies.
1. Polarized screens, project both the left and right images onto the screen at the same time, and then a special filter on the glass polarizes the left and right images differently, such that your 3D glasses then use a different left and right lens to filter the correct image to each eye. Your brain then does the rest.
2. Active shutter glasses, switch between one eye and then the other in sync with the TV, which is alternating left and right images on the screen at a very high rate (50 frames per eye per second). This is fast enough that the brain sees no gaps, and again, takes the two different views from left and right eyes to merge them into an image with depth.
Are the glasses red and green/blue?
No. The red and green/blue glasses also known as anaglyph were used for 80's 3D movies. Although the principles are the same, Digital 3D delivers a far superior experience. Anaglyph images suffer from a loss of colour, as the method for filtering out the left and right images strip out colours from the image. They lead to images that the brain finds too difficult to process which can cause headaches and eye strain.
Do I need a 3D Ready TV?
Yes. 3D ready TVs are already being marketed and will also be HD ready. Some of the main manufacturers are: LG, Panasonic, Sony and Philips.
Active v Passive 3D explained
Active v Passive 3D refers to the type of glasses you have to wear to watch 3D.
Active glasses contain LCD lenses that alternately 'black-out' each eye depending on whether the right or left image is being displayed on the screen. They are referred to as active because they require a battery to operate the LCD lenses. The shuttering occurs so rapidly that you don't see the shutters just the amazing 3D picture.
Passive glasses use polarisation to separate out the left and right image. They are referred to as passive because the glasses do not require any power to operate them. These work with polarised TVs that use circular polarisation to deliver the two images to the viewer. The TVs have a polarized filter integrated into the screen, and when switched into a 3D mode, the filter orientates the light emitting from screen differently for the left and right image. When you put on the passive polarised glasses the left lens has a filter that blocks out the right image and right lens has a filter that blocks out the left image.
One important point to consider is the cost of replacing broken or lost 3D glasses. Active glasses will cost more than polarised glasses due to the additional technology they use. Active glasses will also occasionally need a new lithium battery (similar to a watch battery) when it runs out.
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