What is HDTV? (presented by Philips)
HDTV stands for High Definition Television. It is a digital format that provides an extremely high-resolution picture (2.1 million pixels), accompanied by digitally enhanced sound (Dolby Digital surround sound) all presented in widescreen (16:9 aspect ratio). HDTV refers to the TV itself and the broadcast method (over a digital network), and the way a particular show or movie is produced.
The ultimate viewing experience is achieved when all these aspects of HDTV come together; a show or movie that is produced using high definition technology, is transmitted via an HDTV television signal (from an HDTV channel), and enjoyed on an HDTV television (preferably as part of a total home theater package. The Philips Store offers a wide range of DVD layers, audio, and televisions to help you put together the perfect high definition experience.
Televisions that take advantage of high definition broadcast signals can be divided into HD-ready sets and HD-capable sets. An HD-capable TV provides you with a screen that is able to display an HDTV signal, but it requires an additional external HDTV receiver/decoder to fully interpret the high definition broadcasts. Conversely, the HD-ready sets have an HDTV receiver/decoder built right into the television itself. If you purchase an HD-capable set, you should plan on spending from $300 to $600 on an HDTV receiver. Phlips has an extensive line of HDTVs.
How high definition is different
Most people are watching TV with an analog set. And most TV broadcasts are still coming to your TV as an analog signal. Understanding analog is a good way to begin to grasp what’s makes HDTV so much better. So what makes HDTV so much better? Comparing the two technologies can give you a glimpse.
|Pixels||210,000||2.1 – 2.4 million|
|Scan Lines||480||720 to 1080|
|Scan Method||Interlaced||Progressive or Interlaced|
|Sound||Mono or Stereo||Dolby Digital surround sound|
First, TV screens are made up of pixels. The more pixels per inch, the better the picture. Measuring the number of pixels per square inch is a good way to differentiate between TV sets.
Scan lines are the lines of pixels that run horizontally across the screen and contain picture information. They are refreshed to make the picture change. Again more lines mean more sharpness and detail. Analog has 480 visible scan lines and HDTV ranges from 720 to 1080.
Next, understanding how the TV “paints” the scan lines onto the TV screen can help you understand how HDTV is different from analog. All analog TVs are interlaced (abbreviated as i). This means that the screen paints and re-paints half of all the lines on the screen every other frame, so that the entire screen is updated 30 times every second. There can be drawbacks to this type of scan, like a perceptible flickering that some people find distracting but others don’t even notice.The other way to paint the screen is via progressive scan (abbreviated as p). Progressive scan updates all the lines on the screen at the same time, 60 times every second.Having a choice in between progressive and interlaced is one advantage of HDTV. Many people have their preferences.
Aspect ratio refers to the relationship between the width and height of the TV screen. A standard TV is 4:3, which means that it is four units wide by 3 units high. This breaks down into 1.33 inches of width for every inch of height. 16:9 aspect ration means that the screen provides 1.76 inches of width for every inch high. These dimensions are much closer to the way movies are presented.
Dolby Digital is a digital audio coding technique takes advantage of how the human ear processes sound to create high-quality sound. It masks or eliminates extraneous noises in the audio, so that you only hear what is intended. This helps to reduce the audio information to one tenth of the data on a CD. And Dolby Digital can provide five channels for surround sound quality. This multichannel scheme is known as 5.1 channel. Since not everyone has the equipment needed to take advantage of Dolby Digital’s 5.1 channel sound, a feature is included so that the audio is compatible with any playback device, like a single speaker television. The U.S. cable television industry has also adopted Dolby Digital for DTV. Most television facilities are not equipped to produce 5.1 channel sound. For this reason, many DTV programs use two-channel sound. The 5.1 channel sound is used primarily for theatrical films on pay-per-view channels and at theaters.
Part of the DTV family
Digital television (DTV) is an FCC-defined way that signals are transmitted. Even though HDTV is digital television, not all digital televisions are inherently capable of displaying high definition.
HDTV is just one of many digital formats. Standard Definition TV (SDTV) and Enhanced Definition TV (EDTV) are two other levels of DTV. HDTV is the best you can get–with higher resolution and excellent audio. In fact, HDTV provides resolution that’s about 5 times better than analog TV.
More than just a TV
If you do not want to invest in a high efinition TV now-or ever-you don’t have to. You will still be able to use your analog TV even after everything goes digital. But chances are that by then, you will have had a chance to see the difference. Many people say that they did not understand the excitement over HDTV until they experienced it. Know whether the TV you buy is HD-capable or ready to go. If it is HD-capable (also referred to as an HD monitor), you will need to purchase an additional set-top box receiver to get the signal. HD-ready sets have the receiver built in. Also, some people are fooled because they buy a widescreen plasma TV and think it will give them HDTV performance. Your TV must have the ability to display the resolution defined as High Definition to be considered an HDTV.
If there are no local stations broadcasting in HD, you still will reap the benefits of your investment. A high definition TV improves upon standard broadcast TV. Almost every HDTV has a processor that takes an analog TV image and converts it to an improved progressive scan. But be forewarned: sometimes HDTV buyers are disappointed by how regular television looks on their new sets because minor details or flaws that they might have missed before are exaggerated.
Seeing is believing; it does provide an amazing picture that will change the way you watch TV.