HDTV provides a sharper picture and better sound than standard TV. An in-depth look at HDTV's advantages will help you understand why it will revolutionize your viewing experience.
Aspect ratio describes the width of the TV screen in proportion to its height. When people talk about wide-screen TVs, they are referring to the 16:9 aspect ratio. Most HDTV programs are delivered in this widescreen format. A 16:9 aspect ratio fills more of your natural field of vision and creates a more cinematic experience. In comparison, standard TVs have an aspect ratio of 4:3, slightly wider than a square. In many instances, images are cropped to accommodate your 4:3 screen, resulting in a loss of picture.
The picture elements that make up the images on screen are called pixels. More pixels mean more detail. The highest pixel count is available with HDTV, where up to two million pixels can be displayed.
Resolution is displayed on screen by horizontal and vertical pixels that make up the on-screen image. The number of pixels determines the resolution, and the best resolution on a digital TV is available with an HDTV set. For example, the lines of resolution that you see on older, analog television sets are 705 (width) x 485 (height), at best. In comparison, HDTV offers screen resolutions of 1280 (width) x 720 (height) or 1920 (width) x 1080 (height).
HDTV resolution is available in two formats: 720p and 1080i. The "p" and "i" refer to the scan methods, or how the lines of resolution are delivered on screen. Progressive "p" scanning means that pixels on the screen are refreshed simultaneously. Interlaced "i" scanning refreshes pixels in alternations, first the odd lines, then the even lines. In order to display HD, you need to have a 720p or 1080i signal coming into your TV, and an HDTV set capable of displaying a resolution of 1280 x 720 or higher.
Dolby Digital 5.1
HDTV also offers remarkable sound quality with 5.1 channels of Dolby Digital Surround Sound, the same system used in many movie theaters. Those with a home theater entertainment setup will be able to appreciate shows delivered in Dolby Digital 5.1 surround sound.
Older, analog TV sets offer only two channels of audio, left and right. Dolby Digital 5.1 sends a digital audio signal to six speakers that can be arranged throughout the room, enveloping you with the rich sound from every angle. In addition to five full-range channels (left, center, right, left surround and right surround), a sixth channel handles low-frequency effects (LFE). This sixth channel represents the .1 in Dolby Digital 5.1.