HDTV FAQ
By CNET staff
Jun 12, 2007
URL: http://asia.cnet.com/hd-world/0,3800011581,62020509,00.htm
What are HDTVs and how do they stack up against their regular counterparts. These are examples of burning question addressed in this CNET HDTV FAQ.
The basics
What is HDTV?
Just how much sharper is HDTV than regular TV?
What's the difference between 720p and 1080i HD formats?
How is the sound quality on HD shows?
Can I record HDTV shows and movies?
Do I need a new TV to watch high-definition TV shows?
All about HDTVs
How much do HDTVs cost?
What kind of HDTV should I buy?
Why are HDTV screens wider than regular TV screens?
How will regular TV shows look on an HDTV set?
How will my DVDs look on an HDTV set?
HDTV programming
Is HD available in my area?
What extra equipment do I need to get HDTV?
Will my over-the-air HDTV picture ever suffer from static or ghosting?
What are the other sources of native HD content?
How about those next-generation gaming consoles?
The basics
What is HDTV?
HDTV stands for high-definition television, and it marks the biggest leap forward for television since color TV made its debut in the 1950s. HDTV images are more than twice as detailed as standard analog TV, delivering rich, realistic images, as well as multichannel, movie theater-quality surround sound. HDTVs can display both regular and HDTV images, but they need HD sources to look their best.
Just how much sharper is HDTV than regular TV?
Analog TV--what we've been watching for more than 60 years--has a resolution that's equivalent to about 640 x 480 pixels. An HDTV program, on the other hand, has a resolution that tops out at 1,920 x 1,080 pixels, more than six times as sharp in best-case scenarios. The difference is obvious. One look at, say, a razor-sharp image of a crocodile rolling in the mud on Discovery HD, and you'll understand.
What's the difference between 720p and 1080i HD broadcasts?
The short answer is that they both look great, and most people will have a hard time telling the difference. Here's the medium-size answer: The numbers 720 and 1080 refer to horizontal pixel counts, while the letters p and i refer to the picture-scanning method--either progressive or interlaced. Proponents of 1080i HD will tell you that they offer the most lines of resolution, which is true. However, 1080i images are interlaced, meaning that a tube TV draws the picture in two passes: Once for the odd-numbered lines, and again for the even-numbered lines. For 720p, or progressive, broadcasts, tube TVs draw each frame in a single pass, making for a smoother picture (non-tube variants such as LCD TVs display everything as progressive scan). While most viewers probably won't be able to tell the difference, videophiles tend to prefer the smoother images of 720p. Even higher-bandwidth 1080p broadcasts could offer the best of both worlds, but they're not going to be available anytime soon.
How is the sound quality on HD shows?
At best, standard-definition shows have 4-channel Dolby surround sound (left, center, right, and one rear "surround" channel), but they usually have 2-channel stereo. High-definition broadcasts, on the other hand, support 5.1-channel Dolby Digital surround sound (left, center, right, left and right surround, and a subwoofer--the .1 part, for booming bass). This is similar to the sound you hear in a movie theater or, with the properly equipped home theater, on a DVD. Not all HD broadcasts have 5.1 Dolby Digital yet, but the majority does, and you'll hear--and feel--the difference. Of course, you'll need a home theater system to take full advantage of it.
Can I record HDTV shows and movies?
Not without new equipment. Standard VCRs, DVD recorders, and digital video recorders (DVRs) such as StarHub Smart TV can't record programming in high definition. Eventually, a new high-definition DVD format--either Blu-ray, the competing HD-DVD, or both--will help resolve this problem. But if you must have HD recording and playback today, there are two options. D-VHS is a hybrid VHS format that both plays and recording in HD; unfortunately, D-VHS player/recorders are pricey, there are few prerecorded D-VHS movies available, connectivity is very spotty--you usually need to use FireWire--and because you're using a tape, you don't get any of the random-access benefits of DVDs. Another option is to get an HD DVR which will record your favorite HD shows but it's rare in Asia.
Do I need a new TV to watch high-definition TV shows?
Yes. You'll need both a TV that's capable of displaying enhanced-definition (EDTV) or high-definition (HDTV) images as well as an HDTV tuner (cable, satellite, or over the air) to receive the HD signals. Until recently, most HDTV sets came without their own digital tuners; if you see a set with the label HD-ready, it won't display HD images without a separate HD set-top box. However, HDTV set such as the Samsung IDTV now come with built-in digital tuners for over-the-air HD broadcasts.All about HDTVs
How much do HDTVs cost?
Back in the late 1990s, you couldn't buy an HDTV set for less than S$10,000. In the last few years, however, prices have dropped dramatically. For mere hundreds, you can pick up a 29-inch CRT TV that's capable of displaying HDTV images or HD-compatible. That said, you can still drop the big bucks on an HDTV, especially a large LCD or plasma TV.
What kind of HDTV should I buy?
The right HDTV set for you depends on your budget and the size of screen that you need. For a small room such as a kitchen, an LCD TV is a good choice. If you'll be sitting more than 2m from the screen, you'll want a 32-inch or larger set to appreciate the detail of HDTV. Both flat-panel TV types (LCD and plasma) save space and can be hung on a wall but are relatively pricey. For larger rooms, the best value is a rear-projection set--you may see them referred to as DLP, LCD or SXRD rear-projection. They are bulkier than a flat-panel TV, but these 42-inch-or-larger sets offer a lot more screen real estate for the money. If that's still not big enough, you may want a front-projection TV or, more accurately, a home-theater projector that can fill a 100-inch diagonal screen.
Why are HDTV screens wider than regular TV screens?
For decades, our TV screens have been slightly wider than they are tall; specifically, their ratio of width to height is 4 x 3, known as a 4:3 aspect ratio. Most HDTV screens, on the other hand, have an aspect ratio of 16:9, the same as many movie screens. That means television shows shot in widescreen will look more cinematic, and many movies will fit on an HDTV screen without letterboxing (horizontal black bars at the top and bottom of the screen). There are exceptions, namely ultrawide "scope" movies such as Lord of the Rings and Star Wars, which still have letterbox bars on a widescreen TV. Remember that not all HD programming is widescreen, and when viewing either standard or high-def 4:3 programming on a widescreen HDTV, you may get the opposite effect: Vertical black bars on the left and right of the screen.
How will regular TV shows look on an HDTV set?
It really depends on screen size. Some standard-definition programming may look a little sharper and cleaner on your HDTV set, but more often, it looks worse. That's because all the little flaws and murkiness inherent in regular TV images become that much more obvious when blown up to larger sizes, especially when compared to crystal-clear HD channels. In addition, because SD programming has a narrow aspect ratio of 4:3, you'll see black bars on the left and right sides of the picture if you're watching on a wide-screen 16:9 set. If the black bars bother you, adjustments on all HDTVs can make 4:3 programming fill a 16:9 screen, but when doing so, they crop or distort the image.
How will my DVDs look on an HDTV set?
Excellent, if not quite as good as a true high-def images. Today's DVD players generate between 450 and 480 lines of horizontal resolution, which still counts as standard definition. However, DVDs are very high-quality image sources compared to standard-definition broadcast or cable channels. If you have a widescreen TV, look for anamorphic or enhanced for widescreen DVDs to fully utilize the extra screen real estate.HDTV programming
Is HD broadcast available in my area?
Probably, yes. Some Asian television stations broadcast over-the-air high-definition signals, while others are in the midst of conducting trials. For example, if you're a Singapore StarHub cable subscriber (analog subscribers must upgrade to digital to receive HDTV), you could sign up for its latest HD service for National Geographic Channel HD and Discovery HD documentaries.
What extra equipment do I need to get HD broadcast?
Still using an over-the-air antenna? Believe it or not, that same antenna may work to pick up HDTV signals--all you need is an HDTV tuner (either built into the HDTV or separate and connected to an HDTV-ready set) as well as a local TV station that's broadcasting in HD. If you're a digital cable subscriber, most cable companies rent HDTV boxes for a month fee or subsidized one-time charges.
Will my over-the-air HD broadcast picture ever suffer from static or ghosting?
Over-the-air HD broadcasts are still susceptible to interference from hills or tall buildings, but instead of getting static or ghosting--a faint double image--you'll just get a blank screen or occasional breakup for a weak signal. If you plan on receiving your HD from an over-the-air antenna, you'll need some patience to narrow down the optimal point of reception.
What are the other sources of native HD content?
Another major source of high-def programs is movie titles and documentaries transferred onto or shot in HD by Hollywood studies. These are currently distributed through the competing HD-DVD and Blu-ray platforms and are surfacing in various part of Asia, albeit in limited quantities. Another alternative for the Web-savvy is to purchase the titles off the Web, some online stores such as Amazon.com are offering as low as US$19.95 less shipping for older selections.
How about those next-generation gaming consoles?
Nintendo Wii aside, the Microsoft Xbox 360 and Sony PlayStation 3 are all HD-ready with gaming resolution ranging from 720p to full-HD 1080p. Both also dish out 5.1 Dolby Digital surround sound similar to the multichannel audio featured in HD broadcast. In fact, as these software are cut on DVDs and high-capacity Blu-ray media, their picture and audio quality are generally superior to their broadcast equivalent, primarily due to limited channel bandwidth, etc.
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1: The basics
