What is HDTV?

HDTV is an acronym for high-definition television. HDTV is a new format of digital television programming that provides crisp, clear, vivid pictures. HDTV also supports Dolby Digital 5.1 surround sound, which delivers CD quality digital audio. The spectacular panorama and brilliant color and clarity of HDTV give a feeling similar to being in a movie theater.

How is HDTV different from ordinary television?

One major difference is in the aspect ratio, the difference between the width and height of a television screen. Standard analog televisions use an aspect ratio of 4:3. With HDTV comes widescreen television, which displays a more rectangular image with a 16:9 aspect ratio.

On a square 4:3 television, widescreen films must be edited to fit. On a widescreen television, most movies and sporting events will fill the entire screen.

How clear is the picture?

Another major difference between HDTV and ordinary television is the clarity of the image, which is determined by the number of pixels on the screen. A picture is brought to your television as a group of horizontal lines, which is divided up into tiny squares called pixels (picture elements). Each pixel is made up of even smaller dots of red, green, and blue. A pixel is similar to a mosaic tile picture. If you're trying to make a picture out of large tiles, it will seem rough and jagged.

The smaller the tiles (pixels), the more you can fit into the frame, and the richer the detail and shape of your picture. Today's analog TV sets are generally capable of displaying 640 pixels horizontally and 480 pixels vertically. HDTV quality, depending on the brand and type of set you have, offers 720 pixels horizontally and 1,280 pixels vertically up to 1,080 pixels horizontally and 1,920 pixels vertically. That is almost ten times the number of pixels in an ordinary television, which means a greater degree of sharpness, and lifelike, saturated color.

High-definition television also differs from standard analog television in pixel size. The pixels in analog televisions are slightly taller than their width, which is why distortions are sometimes seen on these sets. Conversely, the pixels in high-definition televisions are square, smaller and spaced more closely together. The total number of pixels displayed on a traditional television is 210,000. Compare that to over 2 million pixels on an HDTV set and what you see a crisper image with vibrant colors and over ten times the picture detail.