Thursday, May 20, 2010

What is the Difference Between HD and 3D?

3D (3-Dimensional) technology seems to have come to the forefront, thanks to the blockbuster world-wide success of the movie Avatar and other releases in the 3D category.

So what is 3D anyway and how does it compare to HD (High-Definition)?

Well, HD (also known as Hi-Def) is video picture quality with considerably higher picture resolution than the traditional Standard-Definition (or SD).

HD generally has about 1 to 2 million pixels per frame which is probably 5 times compared to SD. Therefore, the picture quality is very high and sharp, you can’t compare the quality to SD.
3D on the other hand is another dimension altogether. When watching video in 3D format, the pictures seem to jump outside the screen giving it a real-life-like experience (as if you were experiencing it right there and then). 3D experience is achieved through a technique called Stereoscopy.

It’s based on the way the human brain and eyes work together. An individual’s pupils of the eye are about 6.5 cm (or 2.5 inches) apart, therefore each eye views a scene from a different angle and generates a unique image. 

Avatar (Two-Disc Blu-ray/DVD Combo) [Blu-ray]The brain then merges the images to create a single picture. The slight difference between the image from the right eye and the image from the left eye allows the brain to judge the depth.

There are currently three kinds of 3D technology on the market and each one works differently:

The first one, anaglyph technology, is the most famous one (think red/blue paper glasses) but usually the 3D effects are not so great. This technology has been used countless times in movie theaters, as the typical red and blue glasses are inexpensive.

The second one, polarized (or passive) technology, is the technology you have been exposed to when watching a 3D movie in an IMAX theater (e.g. Avatar 3D, Alice in Wonderland 3D, etc.). To create that 3D effect, two images are projected onto the same screen through different polarizing filters. The viewer wears low-cost eyeglasses which also contain a pair of different polarizing filters.

Shrek 3-DThe third one, active technology, is the most recent one that is quickly becoming the standard in terms of 3D watching at home. With this technology, an HDTV will display one image to your left eye and one image to your right eye.

Active liquid crystal shutter glasses are then worn by the viewer and quickly block each eye in sequence to ensure that each eye only sees the corresponding image being displayed on the 3D TV set.

No comments:

Post a Comment