Why Do I Need a High-Definition TV?

Our current NTSC television system is more than a half-century old. What was state-of-the-art in the 1950s is now woefully inadequate. Today's larger television screens and higher-resolution source material require a better way to reproduce picture and sound than what we've grown used to over the years.

From Analog to Digital -- and High Definition

The first step to improving the quality of our television broadcasts is to move from analog to digital transmission. Just as compact discs replaced records, digital television is replacing our analog broadcasting system. Digital signals don't deteriorate as analog signals do, so a digital broadcast looks every bit as good in your home as it does in the broadcast studio. Simply digitizing a picture, however, does not improve upon a mediocre source format. To dramatically improve the picture, the format itself has to be improved. This leads us to the next step in the evolutionary process: high-definition television (HDTV). HDTV uses digital technology to increase the picture's resolution, resulting in a noticeably sharper and more life-like picture. Digital technology is also used to improve the sound quality, in the form of Dolby Digital surround sound.

In addition, the HDTV format changes the aspect ratio of the picture to more closely resemble the wide screens used in your local cinema. A widescreen display also better matches the human field of vision, which is twice as wide as it is high.

The traditional television screen has a 4:3 aspect ratio -- that is, if the picture is 4 units wide, it's also 3 units tall. The HDTV format embraces a widescreen approach with a 16:9 aspect ratio -- for every 16 units of width, you have just 9 units of height. The resulting picture is wider than a standard television picture and a better fit for displaying widescreen movies and other programming.

So HDTV is digital instead of analog, widescreen instead of square-like and has a noticeably sharper picture than standard definition television. But is it worth the price?

Why HDTV is So Appealing?

There are several reasons HDTV is appealing to both videophiles and normal consumers. All the reasons tend to boil down to a better viewing experience, which is noticeable even to casual viewers.

Here's what you get with the HDTV format:

• Sharper picture. True HDTV -- in either the 720p, 1080i, or 1080p formats -- delivers one million pixels or more of information. Standard TV and DVDs deliver approximately 300,000 pixels. That translates into HDTV delivering a picture more than three times as detailed as what you're used to watching, which is definitely noticeable.

• Less flicker. The increased number of scan lines per frame (and, in the case of the 720p and 1080p formats, progressive scanning) translates into less-visible scan lines. This means you can sit closer to the screen without seeing flicker in the picture.

• More accurate widescreen reproduction. When you display a widescreen movie on a standard 4:3 television, the movie is either letterboxed (with black bars at the top and bottom of the screen) or panned and scanned so that only a portion of the movie is displayed onscreen. With HDTV's 16:9 aspect ration, you can see more of the widescreen movie with less letterboxing.

• Increased picture fidelity. Because HDTV uses digital transmission, the original picture is faithfully reproduced on the receiving end -- there's no deterioration of the picture over long distances or with time. What you see is what was originally recorded or broadcast.

• Better sound. The HDTV format dictates the Dolby Digital 5.1 surround sound format, which is much improved over the NTSC stereo standard. Better picture, bigger picture and better sound -- that's what digital television is all about.

Do You Need an HDTV Set Today?

If all you do is watch normal television programming and your old TV is in good working condition, there is no driving imperative to upgrade to HDTV immediately. Standard programming such soap operas, newscasts and cartoons probably won't look much better on a big HDTV screen than they do on your current TV.

But if you're a big sports fan or watch a lot of movies, the difference in picture quality on an HDTV set is stunning and might be worth the cost of a new set. Watching the Super Bowl or NBA finals on a big HDTV is an eye-popping experience. And you haven't lived until you've watched the latest big-screen blockbuster in full high definition, with room-shaking surround sound. If you need a bigger picture, better picture or better sound, you have a very good reason to upgrade to HDTV.

Of course, if your old TV is on its last legs, or if you're in the market for a new TV for any other reason, the situation is more urgent. If you're shopping for a new set, you definitely want to purchase an HDTV model. That's because HDTV is the future, and you want your new set to handle all the HDTV broadcasts that will soon be commonplace on all major network, cable and satellite channels. Buying a non-HDTV set today would be wedding yourself to obsolete technology. An HDTV set makes your living room future-proof. On February 17, 2009, all television broadcasts will switch from analog to digital. After that date, your old analog (i.e., non-HDTV) set will be obsolete.

What's to Watch?

If you're concerned about not having enough high-definition programming to watch on your HDTV set, find something else to worry about. All the major television networks broadcast the majority of their prime time schedules in high definition, and most major sporting events are also broadcast in high definition.

In addition, most cable and satellite systems have several HDTV-focused channels. These stations broadcast nothing but high definition programming, from nature shows to sporting events to the latest movies. For these stations, it's HDTV 24/7.

You can choose to receive your HDTV programming in a number of ways. If you're only interested in network programming from your local TV stations, you can receive HDTV broadcasts over-the-air, using a set top or roof-mounted antenna. If you're a cable subscriber, most cable systems transmit local/network HDTV stations, as well as high definition pay channels and a few HDTV-only channels. Satellite systems are a bit behind the curve, only offering local HDTV stations in selected markets; they do, however, offer all the national HDTV channels, with the promise of more local HDTV in the months to come.

So however you choose to watch, know that there's plenty of HDTV programming available. And once you make the move to HDTV, you'll never go back.

Michael Miller is a writer and commentator on technology and digital lifestyle topics.