Editor: W. Patrick Tandy
|By John Anderson
For a few years now I’ve
been hearing about certain TV channels being broadcast in High Definition
Television (HDTV). Sure it sounds good, but how much better can it be?
Well, it is much better
Why is It
HDTV signals are digital
signals which offer crystal-clear, noise-free pictures and CD-quality sound that
has a much crisper image than regular analog TV. Your conventional analog TV
uses a cathode ray tube to deliver images to you through a screen resolution of
about 512x400 pixels. HDTV uses a digital display, like your computer monitor,
with a screen resolution that is at least 1,280x720 pixels. A higher screen
resolution means a crisper, clearer picture, free of ghosts, interference and
A current analog TV
picture is made up of 480 horizontal lines. An HDTV picture can have up to 1,080
lines, allowing for stunning picture detail.
Communications Commission has defined 18 different transmission formats in the
“Digital Television Standard.” DTV is the umbrella term for all 18 new formats.
Six of these formats are considered “High Definition” because of their improved
resolution quality. All of these formats require television units with special
decoders to receive the HDTV signals. Yes, to view the enhanced images you will
need a new TV.
In addition to
dramatically improving picture quality, HDTV also offers a wider format. This
makes an HDTV image more like a movie-screen image. The width-to-height ratio –
called the aspect ratio – of HDTV is 16:9. Analog TV has an aspect ratio of only
The difference in aspect
ratio is most noticeable when watching theatrical movies on TV. For analog TV,
the movie must be cut down in a process called “pan and scan,” in which a part
of every scene is deleted to fit the lower aspect ratio. The only way to see the
entire movie scene on an analog TV is to “letterbox” the movie. In letterboxing,
the full movie is shown in the middle of the screen with black bars at the top
and bottom. HDTV eliminates letterboxing and allows you to see the complete
movie on the whole TV screen.
lifelike pictures are 5.1 channels of CD-quality digital audio. Current stereo
TV sets offer only two channels of audio. HDTV delivers true surround sound:
front speakers on the right, center and left, along with two back speakers and a
I Buy An HDTV Set? How Much Do They Cost?
If your TV has
progressive-scan inputs for connection to a computer display card or DVD player,
you’ll be able to see some HDTV signals by adding a set-top box receiver (STB)
which will generally yield some but not all of the advanced resolution of HTDV.
These receivers cost in the range of $400 to $1,000. Otherwise, you can buy new
HDTV sets at most electronics stores. The early receivers were expensive. When
HDTV sets came on the market, they cost as much as $8,000. In a short amount of
time, however, prices have dropped to around $2,000, and they may drop to as low
as $1,500 within a year.
As with most new consumer
electronics technologies, DTV sets have become less expensive since their
introduction. It is expected that prices will continue to decrease over time.
Prices vary depending on screen size, display technology, and other features.
The End of
Digital TV is a more
flexible and efficient technology than the current system, which has been in
place for the last 50 years. In the same bandwidth in which a broadcaster
provides one analog programming channel, a broadcaster may provide a super sharp
“high definition” program or multiple “standard definition” DTV programs
simultaneously. Providing several program streams on one broadcast channel is
called “multicasting.” A broadcaster can also use DTV to provide interactivity
and data services that were not possible with analog technology.
Congress has determined
that the current broadcast television service must eventually completely convert
to digital. DTV technology is more efficient than analog technology and will
allow the same number of stations to broadcast more program material using fewer
broadcast airwaves. DTV offers a more efficient use of the spectrum and will
make increased options in services available to consumers.
Converting to DTV will
also free up parts of the scarce and valuable broadcast airwaves, allowing those
portions of the airwaves to be used for advanced wireless and public safety
services (police, fire departments, rescue squads, etc.).
As of May 1999, the FCC
requires the top TV networks to broadcast a digital signal in the 10 biggest
markets, which represent 30 percent of TV households in the U.S. The networks
plan to expand digital coverage and phase out analog TV broadcasts entirely by
the end of 2006. At that point, broadcasting on the analog channels will end and
that spectrum will be put to other uses. Until the transition to DTV is
completed, television stations are required to broadcast on both their digital
and analog channels.
That is the Question...
Your current television
will work as it does now until analog broadcasting stops. A converter box can be
used to receive Digital TV (DTV) signals and change them into the format of your
current television. However, even with a converter your current analog
television is not capable of displaying the full picture quality of HDTV. To
enjoy the full picture quality, you will need to purchase an HDTV set.