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High Definition Television


HDTV (high definition television) is the new standard in television technology. HDTV signals are transmitted digitally and provide wide-screen, high resolution picture quality along with multi-channel CD sound quality.

What is DTV? What is Digital Television?

The change to DTV is even more significant than the change from black-and-white TV to color TV which occurred in the 1960s. DTV is more than just a new kind of TV set, and more than just high definition (HDTV) programs. DTV is a new way to broadcast and receive TV that gives you a better picture, better sound and more choices than ever before.

Depending on what you ’re watching and what kind of equipment you have, digital television may enhance your viewing experience in any number of ways. You may see movies or sports in stunning HDTV resolution on a 16:9 wide-screen with Dolby Digital sound. Every DTV program you watch will have DVD-quality pictures without any snow, ghosts or static. Some programs may offer multiple audio tracks, and some TV stations may offer up to four programs on a single channel. And others will give you access to interactive content, for learning more about your TV show, shopping online and more. The possibilities are endless.

What do you need to know about DTV? 

How you receive DTV and HDTV broadcasts; 
How to choose a digital television set; 
What the FCC has to say about DTV. 

The good news is DTV is somewhat affordable today, certainly available and easier to understand than you ever thought possible.

First, let's examine some misconceptions about HDTV.

Digital Cable is the Same As DTV.
This is NOT true. 

Digital Cable is certainly digital, meaning it is transmitted as ones and zeros, but that does not make it DTV or HDTV. It is true that you can get DTV from a Digital Cable subscription, but just because you are getting Digital Cable does not necessarily mean you are getting DTV or HDTV signals.

DTV is the Same As HDTV.
This is NOT true. 

Digital Television, DTV, is an umbrella term used for a set of 18 different formats for broadcasting television in a digital format put out by the ATSC. High Definition Television, HDTV, is six of those 18 DTV formats that has a resolution of at least 720p and has an aspect ratio of 16x9.

All Television Will Be HDTV by 2006.
This is NOT true. 

The Federal Communications Commission or FCC has mandated that by 2006 all broadcasters must broadcast DTV signals. This pertains to Over The Air transmissions since this domain is regulated by the FCC, and does not pertain to DTV through Cable TV or Satellite TV companies. 

HDTV takes up a lot of bandwidth and it is up to the Cable and Satellite companies to move from sending you analog signals to DTV signals. To remain competitive the Cable TV and Satellite TV companies will offer upgraded services as market demand occurs. This will mean that they too will offer HDTV content even though the FCC mandate does not affect their domain. 

This also means that broadcasters can send DTV signals that are of lower resolution than that of true HDTV. All the OTA broadcaster must do is meet the minimum requirement of the FCC to broadcast digital signals. This does not mean they have to broadcast HDTV.

More questions about HDTV answered.

What is HDTV?

High-definition television is a format for broadcasting TV programming. The 50 year old format is called NTSC (National Television Standards Committee) and is analog. By contrast, the signals in HDTV are digital and the format is  called ATSC.

Do I need a new television set to watch HDTV?

The simple answer is Yes. You must have a high-definition tuner and monitor to properly decode HDTV signals and display them accurately. Your old analog NTSC  television set simply ignores HDTV signals that are being broadcast. When you want to step up to watching HDTV, you'll need to get a new high-def TV set.

What's different about HDTV versus the old analog signals?

The HDTV signal is digital, resulting in crystal clear, noise-free pictures and CD quality sound. You'll get a much better picture and much better sound. 

HDTV has many benefits.

Benefit: Aspect Ratio
Most analog signal televisions are manufactured in a 4 by 3 aspect ratio, which means the screen is 4 units wide by 3 units high. But theatrically released movies are usually in a much wider aspect, taking advantage of the human field of vision (which is wider across horizontally). HDTV signals are sent in a 16 by 9 aspect ratio, more like the wide scope of movies. HDTV's aspect ratio makes for a more realistic viewing experience.

Benefit: Picture Resolution
Resolution is a measure of picture sharpness. Analog television contains about 480 active scanning lines resulting in a picture resolution of about 330 lines of resolution. By comparison a VHS VCR has about 240 lines of resolution which is why VHS recordings don't look as sharp as the original picture. DVD's offer higher resolution typically on the order of 480 lines of resolution. HDTV offers resolution that is at least twice that of analog television. You can expect razor sharp images from HDTV.

I have heard that there are two HDTV formats — 720p and 1080i. Is there a difference between these formats and can my television receive both these formats?

Regardless of the HDTV format being broadcast, all new HDTV receivers can receive both formats. HDTV televisions will convert any received signal to a format that is compatible with your display. The 720p format uses progressive scanning, which is just like your computer monitor. Progressive scan offers crystal clear images that virtually eliminates those scanning lines that are visible on most large screen televisions.

The 1080i format uses interlace scanning. Scanning lines are less visible on big screens due to the number of lines.

Benefit: Digital Sound
Just as your CDs sound better than your old audio cassette tapes, HDTV's digital audio signal sounds better than standard television's analog sound. Also, some HDTV programs include Dolby Digital 5.1 surround sound. Properly decoded, each audio track can be sent to a different speaker, creating a three-dimensional sound field in your living room. 

What do I need to receive HDTV?

In many areas, HDTV is only available as an over-the-air broadcast signal. This requires the use, in most cases, of an outdoor antenna pointed in the direction of the broadcaster's tower. You will also need a new HDTV receiver that can decode the digital signals. HDTV channels are typically different than your cable or over-the-air channel.

Is HDTV replacing standard television?

Eventually that is the hope, but not immediately. Broadcasters will continue to offer programs in the standard format for a few years.



Why Switch to DTV?

What excites people most about DTV is its brilliant picture quality. There are several reasons why DTV images are so much crisper and clearer:

  1. DTV broadcasts are fully digital, so there ’s never any analog interference such as static, snow or ghosting like you get with analog TV transmissions.

  2. DTV images are often comprised of many more pixels, or picture elements, than analog images. This higher resolution creates sharper, more precise images.

  3. Many DTV programs are “progressive scan ”(as denoted by the “P ”in 480P).This means that every pixel on the screen is refreshed simultaneously, for a flicker-free image. Progressive scan makes text more legible and fast-motion video smoother than on analog TVs with “interlaced ”scan. Interlaced scanning (e.g., the “i ”in 480i) involves refreshing pixels in alternation –first the odd lines, then the even lines. As a result, only half of the pixels on screen are “active ”at any given moment.

  4. Digital TV sets are capable of displaying the true digital picture and sound without down-converting the signal as analog TVs do. Digital TV sets are even capable of making most analog signals look better, by doubling the lines of resolution to a progressive scan image, and through the use of digital filters that remove the unwanted artifacts that can degrade an image.

DTV, SDTV, HDTV-- What does it all mean?

DTV is actually an umbrella term that describes any TV signal that is digital. There are two main types of DTV that you need to know –standard definition (SDTV) and high definition (HDTV). The main difference between them is that HDTV has many more pixels and much greater resolution.

HDTV is the most robust and detailed TV image you can have. It ’s even sharper than a DVD. Depending on the format, an HDTV image can have more than 1,000,000 active pixels. HDTV has a minimum resolution of 1280 x 720 pixels progressive scan (720P) or 1920 x 1080 pixels interlaced (1080i).

Standard definition TV can have either the same resolution (about 150,000 active pixels) or double the resolution of analog TV, depending on whether it is presented as interlaced (same) or progressive (double) scan. But SDTV outshines analog TV because it is not prone to static, snow and ghosts the way analog is. SDTV can also be either 4:3 standard aspect ratio or 16:9 wide-screen.

When will the switch to Digital Television occur?

It is already happening and will be phased in gradually over the next few years.

The FCC (Federal Communications Commission) has mandated that all TV broadcasts must be in Digital format by the year 2006.

Broadcasters who begin DTV transmissions, will simultaneously broadcast analog TV as well.

Also take note that these mandates have not stated anything about cable broadcasts and/or high definition broadcasts. It is up to the cable companies to make the switch to digital on their own. As for the actual TV stations, they are only required to broadcast in a digital format and broadcasting in high definition is completely up to them.

How do I get DTV?

Getting digital TV is easy. There are three things that you need to view true, all-digital DTV: First, you need a digital source such as over-the-air broadcast, digital satellite or true digital cable. Second, you need a set-top box or built-in tuner to receive, tune and decode the digital signal. Third, you need a digital TV to display the brilliant digital picture and sound.

The good news is you don’t have to upgrade to DTV all at once. You can view a DTV source on an analog TV by connecting a digital set-top box (tuner). Or you can get a DTV set, which will give you the most from every source you watch – then add a set-top box and digital source later. If you have a progressive scan DVD player, you’ll immediately notice the difference that DTV makes.

What about the new digital TV sets, what kind of digital TV sets are available and what are the new TV display technologies?

The new digital super-thin flat screen TV displays are impressive. Very large screen sizes are possible. Some can be hung on your wall. Two of the more popular TV display technologies are Plasma and LCD. See Plasma vs. LCD for an explanation of the advantages and disadvantages of each.
Another popular technology is DLP. 

There are a lot of choices but don't feel bad about not knowing which to buy. Even the big world-wide electronics manufacturers cannot agree on which display technology is best or which one will ultimately prevail in the marketplace. Sony has said they think LCD is the way to go, even though they also make Plasma displays. Panasonic has said they think Plasma is the way to go even though they also sell LCD displays. See TV displays for more.

HDTV is part of several standards incorporated in digital television or DTV. Basically, DTV is composed of three separate standards:
  • HDTV 1080 (1080 lines of resolution, 16:9 aspect ratio)
  • HDTV 720 (720 lines of resolution, 16:9 aspect ratio)
  • SDTV (480 lines of resolution, 16:9 or 4:3 aspect ratio)

Although the ATSC defines both 1080 lines and 720 lines as HDTV, there are differing views with respect to how HDTV should be defined.


United States major market television stations began transmitting DTV in the fall of 1998. The number of new DTV stations on the air is increasing every month.

 
HDTV is the biggest breakthrough in broadcasting since color TV. It offers wider pictures with greater detail and the clarity of motion pictures. Compared to standard television (NTSC), the true HDTV image has twice the luminance definition - vertically and horizontally - and is twenty-five percent wider. Standard television aspect ratio is 4:3 (four units wide, three units high) - the HDTV aspect ratio is 16:9. The 16:9 ratio is much closer to the average wide-screen image shown in movie theaters. The biggest difference, and the greatest appeal of HDTV, is its clarity.

  True HDTV pictures are composed of 1080 active lines (1125 total) whereas current standard television pictures are composed of only 486 active lines (525 total). While it is possible to see the lines that make up standard television pictures, HDTV lines are not at all noticeable. The fine-grained HD picture contains five times more information than does the standard television picture and is accompanied by multi-channel, CD quality sound. The difference in video and sound quality is dramatic.

What shows can I see right now in High Definition HDTV?

Over 1,000 TV stations now broadcast digital signals in over 200 markets which cover 95% of U.S. TV households. 

Sports broadcasts offer compelling content for high definition TV. The Super Bowl, NFL playoffs, and NBA playoffs were broadcast in high definition. Events that will be broadcast in HDTV include the NCAA Final Four, the NHL All-Star Game, the Masters Tournament, and  Monday Night Football to name a few.

Off-Air HDTV Programming
  CBS broadcasts most of its primetime programming in high definition. Among the series available in HDTV are:

JAG, CSI, Judging Amy, The Agency, Hack, The Guardian, Presidio Med, The Fugitive, Becker, Touched by an Angel, Still Standing, Everybody Loves Raymond, Yes Dear, King of Queens, and The Young and the Restless.
 
  ABC offers NYPD Blue, Alias, The Practice, According to Jim, My Wife and Kids, Who Wants to Be a Millionaire, George Lopez, Married to the Kellys, Life with Bonnie, The Wonderful World of Disney and a much larger selection of feature films every month.
 
  NBC broadcasts The Tonight Show, ER, American Dreams, Ed, Crossing Jordan, and Frasier. NBC executives have stated a commitment to producing a more significant portion of its primetime lineup in HD in the near future. 
 
  FOX is working on expanding broadcasts in HD.
 
  Warner Brothers has dramatically increased its level of HDTV programming. Series offered in high definition  include Reba, Everwood, Smallville, Angel, Gilmore Girls, and What I Like About You
 
  From early on, PBS has supported HD broadcasting and currently airs documentaries, specials, and performances via select affiliates in many parts of the country.
 


DIRECTV® HDTV Programming

DIRECTV currently offers outstanding high definition programming through its new DIRECTV® HD PACKAGE, which includes ESPN HD, Discovery HD Theater, HDNet, HDNet Movies, as well as through its premium programming packages HBO and SHOWTIME. DIRECTV plans to aggressively continue its HD programming expansion.
 
The HD Package includes:
 
  ESPN HD 
Sports events, news, information and entertainment, including ESPN games from MLB, NBA, NFL and NHL.
 
  Discovery HD Theater 
Programs about nature, travel, geography,
world culture, science & technology
and more.
 
  HDNet 
A 24-hour network featuring live sports like NHL® and MLS® games, boxing, drama series, concerts and original news and documentary programming including HDNet World Report and Across America.
 
  HDNet Movies  
Delivers a 24-hour schedule of blockbuster movie titles from Warner Bros., Sony, and other major studios, as well as made-for-TV movies, independent films and shorts.
 
  Channels 80,81
offer many of America's favorite primetime original series.
 
  HBO-HD® (DIRECTV channel 509) is available as part of DIRECTV's HBO® premium movie package. With over half of HBO movies broadcast in high definition, there's no shortage of great entertainment. One of HBO's most notable highlights are The Sopranos, Sex in the City and Six Feet Under.
 
  SHOWTIME-HD® (DIRECTV channel 543) The SHOWTIME HD Channel is broadcast from DIRECTV's Satellite in the 110 degree orbital slot position. SHOWTIME adheres to original aspect ratio in which movies were filmed and was among the first to transmit Dolby Digital 5.1.

If you currently receive HD programming using an 18"x24" elliptical dish with dual LNBs, you will need to upgrade to a triple-feed configuration by adding a Sat C kit in order to receive the SHOWTIME HD Channel or purchase a Triple LNB Dish. Showtime offers several popular original series, including The Chris Isaak Show, Queer As Folk, Jeremiah, and plans to offer Earthlings, Dead like Me, and Out of Order
 


About HDTV

Index

Digital and High-Definition-Television

The Digital Difference

Resolution

Interlaced and Progressive Scan

Progressive Scan System

High-Definition-Television - vs. - Standard Definition Television

Picture Pixels

Why Is "Wide-Screen" TV The DTV Standard?

Why "Wide-Screen"?

ATSC DTV Picture Formats (Compression Formats)

 

Digital and High-Definition-Television

How does digital television (DTV) differ from the traditional, analog TV, with which we all grew up? Most of us have never questioned the technology hidden behind the TV picture tube; nor given any thought to how our favorite TV programs show up in our living rooms. Without getting into a lot of "hi-tech-stuff," (at least we'll try not to) let's start by looking at the TV set we've all been familiar with for the past 50+ years.

The standard-analog or NTSC-TV, (National Television Standards Committee) transmits only the video signal, containing no other information. But a major problem with analog signals is that between the transmitter and your TV set many things can interfere, thus distorting the picture you see. From a plane flying far overhead, to hilly terrain, tall buildings and even atmospheric conditions, all are obstacles that can interrupt the signal.

Also, the strength of the analog signal is critical; a weaker signal can cause "snowy" and distorted pictures - something with which those of us who remember "pre-cable/satellite" are too familiar.

 

The Digital Difference        Goto Top

Digital TV signals are made up of coded instructions - the same 'bits' of 'ones and zeros' that make your computer work, and give life to your 'CD's' and 'DVD's' - which are transmitted to your Digital Receiver, (aka: Tuner, Decoder or Set-Top-Box "STB") which in turn deciphers the code.Your receiver isn't concerned with the signal strength, or what conditions exist between you and the transmitter. As long as the signal gets to the receiver, it can read the code and reproduce a near-perfect picture.

A distinct advantage of digital broadcasting is that bad reception is a thing of the past. One reason Cable TV caught on is because it delivers clear TV pictures without regard to the viewer's location. Viewers don't have to be constantly adjusting the antenna in an attempt to tune in a clear picture.

DTV eliminates "snow" and "ghosting" caused by the weak signals from distant or blocked transmitting towers. If your analog television set is not receiving a strong, undistorted signal from the tower, you will not get a perfectly clear picture.

Both digital and analog television signals get weaker the farther they travel away from the transmitting tower. On an analog TV, the picture slowly deteriorates from bad to worse for more distant receivers. However, the picture on a digital set will stay perfect until the signal becomes too weak for the receiver to distinguish between a (1) and a (0), at which point the image disappears completely. You could compare this to sending Morse Code. As long as the person at the other end can make out the dots and dashes being transmitted they will be able to read the message. Once they lose the distinction between a dot and a dash they lose the message. Digital TV acts the same way; instead of sending dots and dashes, it sends millions of (1's) and (0's) every second. The bottom line ... you either receive a 100% perfect quality image, or nothing at all. What this means to you, the digital, or high-definition-television viewer, is that you will never get a "bad" picture. Either you have a picture or you don't. However, if you are receiving over-the-air or "off-air" (OTA) broadcasts, it is crucial for the antenna to be accurately directed towards the signal source - the transmitting tower of the station you are watching.

In High-Definition-Television, the picture displayed on your television screen is digitally transmitted, but it must also meet the "ATSC" (Advanced Television Standards Committee) 'Standards for High-Definition-Television' in order for it to be "true" HDTV. The image you see on your television screen is comprised of a series of horizontal lines. An electron gun 'shoots' energy beams (light) which strike a layer of phosphor on the inside surface of the picture tube, causing it to glow. These glowing lines create the image displayed on your TV screen. How they are formatted, which resolution is used, what standards are met, determine the type of television picture you are receiving.

 

Resolution        Goto Top

Basically, TV 'resolution' refers to how many horizontal lines are displayed on your TV screen. (Although it is the horizontal lines that are counted, this is usually referred to as "vertical resolution" because the lines are counted from top to bottom - or vertically).

Note: Resolution is sometimes expressed as the total 'pixel' count, which is a product of the number of lines and number of pixels per line.

 

Interlaced and Progressive Scan

There are two methods that can be used to display the lines on the screen - either "Interlaced" or "Progressive Scan." The NTSC adopted the standard known as "interlaced" to provide a method of compression that achieves a higher resolution using less-costly circuitry. The NTSC-analog standard is "525 lines - interlaced, at 30 fps" (frames per second). This may be written as: 525-i/30 fps; however, only 480 lines are used to make the visible image, the remaining lines contain information pertaining to picture synchronization and are not seen. For this reason, the stated 'resolution' usually refers only to the visible lines; ie... 480-i/30 fps. In using the "Interlaced" method, the 480 lines are created in two fields (phases). The "scan-rate" for these (2) fields is 60hz (60 times per second). In phase #1, the first 1/60th of a second, 240 lines (the odd numbered lines - 1,3,5 etc) are scanned on the tube. In the second 1/60th of a second, (phase #2)- the remaining 240 (even-numbered) lines are scanned. Thus each field of 240 lines is scanned 30 times a second, and produces one complete frame (30) times per second; (1/60 second X 2 fields = 2/60 second = 1 complete frame, 30 times per second). It's the total lines-per-image that indicates the resolution of the system, ie. (525i or 480i). 

There are other analog systems that have resolutions of less than 480 lines per image. For instance, DVD's have 450 lines; while VHS players come in with a poor showing of only 240 lines.

 

Progressive Scan System        Goto Top

Digital TV has formats that use the interlaced system; however, DTV also uses another system, called "Progressive Scan." The progressive system scans the total number of lines, 60 times a second; not half and half as in interlaced. This means you see the complete image displayed on your TV screen two-times more often. This results in smoother motion in moving images, having less motion artifacts and none of the visible "flicker." A progressive scan system with 480 lines of resolution is written, "480p."

 

High-Definition-Television - vs. - Standard Definition Television

The ATSC has assigned (18) formats to Digital TV. At the current time, in HDTV we are primarily concerned with just two: 1080-i and 720-p. "True" High-Definition-Television may have, either 1080 interlaced lines, or 720 progressive-scanned lines. (Higher resolutions may be introduced in the future; for instance 1080-p, which is not currently used because of high manufacturing costs).

Digital broadcasts in 480-i or 480-p are classified as "SDTV" (Standard Definition). SDTV has a sharper, crisper picture than NTSC-analog TV. It is superior to analog because the transmitted signal is digital. SDTV can be either (480i) or (480p) but is more often 480p. On smaller (direct-view) TV sets, 480p is noticeably better than the analog 480-i, but on the much larger, "projection" sets, SDTV can not compare to High-Definition-Television's 720p, or 1080i formats.

Note: 1080i displays more lines and thus delivers more information. This produces better "spatial resolution" - producing sharper pictures when the image is "still" or has little motion. Manufacturers have generally preferred the Interlaced format because more lines of resolution can be delivered with less bandwidth, resulting in lower costs. 

Many viewers, including those in the computer world, prefer the 720p format because its full frame, progressive scanning, enables it to reproduce fast-moving action and graphics without blurring the image. Thus, 720p is said to have better "temporal" resolution. Incidentally, if you have a computer system - doesn't everyone? - your monitor uses progressive scan. 

Both sides in this (i/p) debate are dug-in, with ardent supporters and aggressive detractors abounding on each side. But which is the better system is a subjective determination. You might say "it's in the eye of the beholder."

The different television networks have individually selected the particular DTV format used by their respective networks for transmitting High-Definition-Television broadcasts. 

For instance, ABC uses 720p, while CBS transmits in 1080i. The important note for you, regardless which High-Definition-Television System you buy, is to be sure it is capable of "up-converting" or "down-converting," enabling you to view all transmitted signals in your set's designated (native) format or native resolution.

 

Picture Pixels        Goto Top

High-Definition-Television displays pictures that contain significantly more detail, resulting in much 'crisper' pictures. Images viewed on TV screens are made up of small picture elements known as 'pixels.' Each of these pixels is made up of three, closely spaced 'dots' of color - red, blue and green.

Combined together on the TV's phosphor screen, and viewed from a distance, the colors are seen as one. The phosphor at each of these dots emits light directly proportional to the intensity from the electron beam that hits it, as it scans across the screen.

On traditional, NTSC TV's 256 levels of intensity are possible for each of the three colors. The result is a range of 16.8 million colors for each pixel. The pixels in the analog system are slightly 'taller' than their width. Get up close to an analog screen - especially the larger projection sets - and you can easily see the red, blue and green rectangles. This is why distortion is sometimes seen on traditional, NTSC TV's.

The pixels in HDTV sets are square; they are also smaller, and spaced closer together. There can be (4 1/2) HDTV pixels in the same space that a single NTSC pixel requires. The result is that High-Definition-Television can display at least 4.5 times more detail than NTSC-analog TV.

 

What Is "Aspect Ratio"? Why Is "Wide-Screen" TV The DTV Standard?

DTV sets are sold in two 'Aspect Ratios.' Aspect Ratio refers to the ratio between the horizontal (width) measurement and the vertical (height) measurement of the screen. This ratio is also used in reference to how the picture is transmitted and displayed on the screen. The two aspect ratios used in DTV are (4:3) and (16:9). That is, (4) units wide by (3) units high, and (16) units wide by (9) units high respectively. Your NTSC-analog television has an aspect ratio of (4:3); the screen appears almost 'square' because it has just slightly more width than height. For instance, a (4') wide screen would have a height of (3'). Digital Television's (16:9) 'wide-screen' is approximately (1/3) larger than a comparable (4:3) set. As a comparison - if you have a "wide-screen' set measuring (16) units wide by (9) units high, then a comparable (4:3) set would measure (12) units wide by (9) units high. The ATSC adopted the 16:9 "wide-screen" aspect ratio as the standard for Digital-HDTV, because significantly more information can be displayed on the screen. And Wide-screen DTV/HDTV sets appear more 'rectangular' than the familiar 'square' shape of your NTSC-analog set.
 

Why "Wide-Screen"?        Goto Top

Believe it or not, the 4:3 aspect ratio was originally developed by W.K.L. Dickson in 1889, while working at the famed Thomas Edison Laboratory. He was running experiments with a Kinescope (motion-picture) camera. He made the decision to create his film (1") wide and (3/4") high. This ratio soon became the standard of the film industry. In 1941, when the NTSC proposed the standards for broadcast television they had no reason not to adopt the same 4:3 ratio used by the film industry.

In the 1950's, Hollywood found they needed to provide the public with a specific reason to buy movie tickets, when it was easier for them to sit home and enjoy free television. Besides trying innovations like "3-D", studios experimented with the aspect ratio; "Cinemascope" was one of the early 'wide-screen' ratios that can still be seen today.

The reasoning that led to wide-screen formats is simply that the wider view is closer to the human field of vision. Because the viewer is visually drawn more into the action with wide-screen, the enjoyment level is enhanced. Our vision is optimized within a 30-degree field of vision. We see details best within the 'center' area of this field, while our peripheral vision is better at detecting motion. Beyond 30-degrees there is no visible benefit.

The familiar 4:3 ratio allows us only a 10-degree field of vision. In the theater, 'wide-screen' formats were easy to reproduce by using more or less of the area projected on the screen, as needed. However, as movies were displayed on TV screens, and later made into videos, the aspect ratio became more complicated. Initially, movies were 'cropped' to 'fit' 4:3 analog-TV sets.

This is accomplished by a process called "pan and scan," which involves moving the 4:3 viewing area back and forth, to center the scene on the primary action. While pan and scan is okay if nothing is occurring in the peripheral areas, often, important information in these areas is cut off. In addition, pan and scan may not give the viewer the same "feel" that the original film had, because the scene is not actually seen as the movie director intended.

To enable movies to be viewed in their original, 'wide-screen' aspect, the "letter-box' process was developed. With 'letter-boxing,' the picture's height is reduced, thus allowing the full width of the image to fit the TV screen. This enables you to see the entire scene the way it was filmed.

However, reducing the image height requires removing some information that leaves a portion of the vertical area 'blank' - this appears as a black 'bar' on the screen. The image is displayed in the center of the screen, with the blank area divided into two, horizontal, black 'bars' across the top and bottom of the screen. These bars increase or decrease, as the aspect ratio changes. However, 'letter-boxed' movies, originally filmed in extra-wide format, can be especially troublesome when viewed on smaller TV screens, due to the extremely reduced viewing area.

It's important to understand that the digital signal can be transmitted in either the (4:3) or (16:9) aspect ratio. (Although it's alleged that all DTV will be broadcast in (16:9) at some future date)

Your DTV will be able to display both aspect ratios - regardless of which ratio is 'native' to your set. When you watch a program that is transmitted in (4:3) aspect ratio, on a (16:9) screen, the image will be "window-boxed" - centered on the screen with vertical black bars ('gray' on some models) on both sides. When you watch a (16:9) program on a (4:3) screen, it will appear "letter-boxed" (previously described) with horizontal bars across the top and bottom of the screen.

 

 

 

What is HDTV

Have you walked into your electronics store lately and seen the big wide-screen televisions. They look impressive and are super thin compared to your old home TV set. These new screens are flat and can be hung on the wall (with the proper brackets). [See example] They are part of the new digital television era. Not all flat displays are high definition however and more importantly, not all are capable of showing the impressive high definition programming. 

Shopping for one of the new displays is not as easy as it once was when you bought a new TV set. Your old analog TV sets were basically made up of the same NTSC signal technology, and they just were different sized screens and some had added features. You bought a 9 inch screen TV set for your kitchen and a 27 inch screen TV set for the living room and that was that.

You were hooked up to cable TV or used a rooftop antenna for VHF and UHF reception. In the old days, you tuned in channels 2 thru 83 on the old rabbit ears antenna and the UHF circle antenna on your TV set (manually adjusted for good reception). You connected your VCR for recording TV shows and possibly your 2-channel home stereo gear for better sound. 

Today things are going to be changing for your home entertainment. We're moving to digital technology, disc instead of tape, sharper visual presentation and better audio. High Definition TV is part of this change. The transition has already begun. For a more complete history of what has been happening click here.

For answers to more frequently asked questions, click here.

Did you know that High Definition television signals are broadcast on UHF right now! That's right! A TV station broadcasting traditional analog NTSC signals for example on VHF channel 5 might be broadcasting HDTV signals on UHF channel 55. See this chart for a complete listing of TV stations in the United States which could be broadcasting HDTV programming.

Digital TV relies on a compression and encoding scheme known as MPEG-2 to fit its stunning images into a reasonable amount of bandwidth. In each image, the MPEG-2 software records just enough of the picture without making it look like something is missing. In subsequent frames, the software only records changes to the image and leaves the rest of the image as-is from the previous frame. MPEG-2 reduces the amount of data by about 55 to 1.

MPEG-2 already is the industry standard for DVD videos and some of the satellite TV broadcast systems. Compression reduces image quality from what is seen by the digital camera at the studio. However, MPEG-2 is very good at throwing away image detail that the human eye ignores anyway. The quality of the image is very good, and significantly better than traditional analog TV.

The use of MPEG-2 permits an HDTV receiver to interact with computer multimedia applications directly. For example, an HDTV show could be recorded on a multimedia computer, and CD-ROM applications could be played on HDTV systems. A digital TV decodes the MPEG-2 signal and displays it just as a computer monitor does, giving it high resolution and stability.

Feb. 17, 2009 marks the end of analog TV broadcasts and the beginning of digital TV broadcasts. At issue is the American households getting only over-the-air TV reception on their analog older TV sets. To continue getting TV programming after 2/19/2009, these households will have to 1) buy a new digital TV with a digital tuner or 2) obtain a converter box which will receive the digital TV signals and convert them to an analog signal. See DTV 2009 for more information on the $40 coupons you can apply for to defer the cost of the box and also how to hookup the converter box to your TV set.


How do I get HDTV?

What HDTV displays are available and how much do they cost?

What do I need to see HDTV?

How do I connect my DVD player?

Quick HDTV Guide

What is native resolution?



Digital TV Manufacturers

Who makes HDTV sets?

Most of the big world-wide electronics firms you have seen in other products such as CD players, DVD players, audio players, digital cameras and the like all make the high-tech HDTV displays. The following list is not all inclusive but shows most of the brands you will see when looking for an HDTV. The top names have warranties on their products and provide customer support.

LG Electronics

Korean-based LG Electronics makes TV/Video products including flat screen HDTV.

Fujitsu

Fujitsu General America, Inc. is a leading provider of a wide variety of innovative and highly reliable products. Since introducing the world's first color plasma display monitor in 1993, Fujitsu has emerged as the leader in plasma display technology. In 2004, Fujitsu also entered the LCD Front Projector market with the introduction of its high resolution LCD-Projector.

Hitachi

Hitachi enjoys a unique position among manufacturers of consumer electronics. Hitachi designs, develops and manufactures proprietary, Large Scale Integration, or LSI microprocessors-the intelligence behind any digital product. Hitachi is a partner in the world's most advanced plasma display facility. Hitachi builds a wide range of direct-view, projection and plasma television products.

JVC

JVC Company of America is a subsidiary of Victor Company of Japan, Limited. JVC - America is currently marketing products in the following categories: Digital Video Camcorders, VHS-C Camcorders, Digital Still Cameras, Super VHS VCR’s, VHS VCR’s, DVD’s, Satellite Systems, Color Televisions including flat-screen digital, Home Audio Components and Systems, Personal Audio Systems, Mobile Entertainment Products and Recording Media.

Panasonic

Panasonic makes many excellent digital TV displays as well as a multitude of other consumer electronics products including DVD recorders, camcorders and media.

Mitsubishi

Mitsubishi Electric digital televisions include some of the best large-screen projection HDTV's in the marketplace.

NEC

NEC makes Plasma digital TV displays.

Philips

Royal Philips Electronics of the Netherlands is one of the world's biggest electronics companies and Europe's largest. Philips is tenth on Fortune's list of global top electronics corporations. They are a world leader in digital technologies for television and displays, wireless communications, speech recognition, video compression, storage and optical products

Pioneer

Pioneer North America, Inc. is a part of Tokyo-based Pioneer Corporation, a world leader in digital entertainment products. Pioneer is respected for its role in such innovations as interactive cable TV, the Laser Disc player, developing the first Compact Disc player for the car and the first detachable face car stereo, DVD and DVD recording, plasma display, and organic electroluminescent display.

RCA

RCA has been bought out and merged with several companies in recent years but you'll still see TV displays with the RCA logo.

Samsung

Samsung is a leading manufacturer of home entertainment video and audio products as well as products like phones, computers, home appliances, fiberoptics and more.

Sanyo

Sanyo has been in the consumer electronics business for decades and makes a variety of products including digital TV displays.

Sharp Electronics

Sharp makes flat screen TV displays from small 15 inch screens to very large LCD displays with excellent picture quality.

Sony Electronics

Sony Corporation of America is the U.S. subsidiary of Sony Corporation, headquartered in Tokyo. Sony is a leading manufacturer of audio, video, communications, and information technology products for the consumer and professional markets. Sony makes both Plasma and LCD digital flat screen TV displays.

Toshiba

A world-wide supplier of all kinds of electronics including digital TV displays.

Viewsonic

Headquartered near Los Angeles in Walnut, Calif., ViewSonic Corporation has quickly become a leading global provider of visual display products selling LCD and Plasma TV displays.


Zenith
Zenith makes both LCD and Plasma displays.


What are the popular screen sizes in digital TV displays?

Screen sizes for the thin TVs vary from a small 15 inch (possibly not HDTV capable) to very large 60 inch, 82 inch and more. However most of the screens will be in the 32 inch, 42 inch, 50 inch sizes  which is what most people want. This gives you the wide-screen view and possibly High-Definition capability and great resolution for HDTV. A 50 inch screen is amazingly large in a Plasma technology display. You have to consider how much a 50 inch Plasma display weighs. It's heavy, over 100 pounds and measuring about 60 inches wide by 33 inches high by 5 inches deep. Bigger than 50 inch screens can be Plasma but most likely are projection TVs (DLP, LCos).

How much do digital TV displays cost?

Prices are coming down all the time. Last year's $6,000 Plasma display goes for $4,500 today. Small sets can go for $700 or less but try to get at least the 16x9 wide-screen (most likely a 17 inch at least). 

A few thousand dollars will buy a decent digital display capable of HD while a few thousand more will buy a much better overall display with all the extra features. A 22 inch LCD might cost $1,600 or so and be HD ready. The bigger displays cost the most. They don't necessarily have a better picture. 

Where should I buy my HDTV?

There are online consumer electronics vendors such as Vanns (www.vanns.com) located in Montana and Tweeter (www.tweeter.com). 

Also try Onecall (www.onecall.com) located in Washington State and  BHphotovideo (www.bhphotovideo.com) located in New York City.  

Many of these vendors may not charge sales tax to most people (those out of state) or possibly even shipping charges. Then there are the national retail stores such as Circuit City and Best Buy where you can take a look at the various digital TV displays up close. Here you may find the lowest price but the least technical expertise. 

Also, if you look around, most large cities have high-end specialty retail stores that sell only top-of-the-line audio and video products. Some of these types of stores have been in business for decades and have a solid reputation although the prices will tend to be higher. You may find the best technical expertise at these types of stores. Buy from a trusted source known to you or someone you know and trust. Considerations include delivery and setup, customer support and return possibilities if all goes wrong.


What should I look for in a digital TV?

o Tuners

Plasma display panels (PDP) and LCD displays may contain an analog television tuner (NTSC) and even may contain a digital television tuner (ATSC). Check which tuners, if any, are integrated in the set. To receive HDTV signals you may need to buy a HDTV tuner box to decode the High-Def signals. 

o Connection jacks

You need to have plenty of audio and video connections on the set to plug in all your components. Composite video, component video, DVI or HDMI along with audio jacks. A Cablecard slot might be desirable if you get your TV signals from Cable TV. Check which connection jacks and slots are present.

o Pixel Resolution

A 1024x1024 or 1024x768 pixel display will not show true HDTV which is 1920x1080i or 1280x720p but it will be close. The display's Up-conversion / down-conversion circuitry will optimize the picture for each signal source. Here it depends what you think is good enough but suffice it to say you need to check the native pixel resolution.

o Features

Some features you might want include PIP or  picture-in-a-picture where you can watch two shows at once, a sleep timer to auto switch off the set, and digital media slots for showing digital camera pictures etc. on the display.

o Sound

Keep in mind that digital TV  displays do not necessarily have speakers like your analog TV has. Some do have stereo speakers built in but if not, you'll have to connect your stand-alone speakers up to hear the audio. For Dolby Digital 5.1 shows, you'll need the full compliment of left, right, center, surround speakers and a subwoofer along with an amplifier or A/V receiver to drive them.


more ..


ATSC DTV Picture Formats (Compression Formats)

DTV
Format

Scan
Lines

Horizontal
Pixels

Aspect
Ratio

Picture Rate
I= Interlaced P=Progressive

HDTV

1080

1920

16:9

60I, 30P, 24P

HDTV

720

1280

16:9

60P, 30P, 24P

SDTV

480

704

16:9

60P, 60I, 30P, 24P

SDTV

480

704

4:3

60P, 60I, 30P, 24P

SDTV

480

640

4:3

60P, 60I, 30P, 24P

Display Parameters for DTV Formats

Feature

NTSC
Composite
Digital

DVD
ITU-
R-601

DVD
Line 
Doubled

DVD
Line 
Quadrupled

ATSC
720P

 

ATSC
1080I

 

ATSC
1080I
Line Doubled

Frame Rate (Hz)

29.97

29.97

59.94

59.94

60

30

60

Field Rate (interlaced only) (Hz)

59.94

59.94

Progressive

Progressive

Progressive

59.94

Progressive

Aspect Ratio

4:3

4:3/16:9

4:3/16:9

4:3/16:9

16:9

16:9

16:9

Active Picture Horizontal Pixels

768

720

720

720

1280

1920

1920

Total Horizontal Pixels

910

858

858

858

1650

2200

2200

Active Picture Lines/Frame

483

480

480

960

720

1080

1080

Total Lines/Frame

525

525

525

1050

750

1125

1125



Widescreen HDTV display, tuner and remote control

A 42" Plasma HDTV can deliver superb picture quality. The 16:9 screen ratio produces theater style widescreen presentation with superb image resolution. Electronic circuitry will try to optimize picture performance for sharper resolution from DVD, VHS, DBS and cable sources that rivals high definition resolution. Incoming high definition signals are also digitally mapped for a crisp and clear picture. An ATSC integrated tuner allows reception for both aired and off-air broadcasts. A CableCARD™ Slot provides cable subscribers with access to digitally encrypted channels, without a set top box, through a CableCARD provided by your television provider. A digital amplifier divides power between attached speakers. A semi-floating glass panel allows you to adjust the screen angel to ensure the perfect viewing angle. 

  • Some displays provide the ability to watch two programs side by side at the same time giving you the flexibility to watch two games or television programs at once
     

Typical specifications of a digital TV display.

Definitions:

Contrast ratio is the proportion between the brightest and darkest section of an image. The higher the contrast ratio, the clearer the image and the better the picture (example; 1000:1 is better than 600:1) A higher contrast ratio results in well-defined, more realistic images.

Comb filter - This advanced filter analyzes sequential fields of information to eliminate dot crawl and color bleed. Additionally, the 3D Y/C (4MB, 10-bit) Comb Filter significantly reduces detail noise, seen as shimmering or flicker, in complex or intricately detailed scenes. It eliminates most video noise normally seen in RF and composite video signals.

Display   
Screen Size (Diagonal)  42" 
Aspect Ratio  16:9 
Pixel Resolution  1024 x 1024 
Brightness  1000 cd/m2 
Contrast Ratio  3000:1 
Displayable Colors  16.7 million 
Viewing Angle  160° 
Comb Filter  3D Y/C digital comb filter 
Video   
Video System  ATSC
NTSC
QAM 
HDTV Compatibility  480p/1080i 
TV Scan Lines  SDTV: 480i
HDTV: 1080i 
TV Tuner  NTSC (Standard analog broadcasts) 
CableCARD Slot  Yes 
Speaker   
Sound  Stereo 
Power  25 W per channel (2 channels) 
Orientation  Vertical 
Input/Output Connectors   
Inputs  HDMI: 1
Composite RCA: 3
S-Video: 3
Component: 2
Control S:
Outputs  Subwoofer: 1
Control S:
Control Port  Control S 
Convenience   
Picture in Picture (PIP)  Multi-source PIP 
Digital Media Slot  NA 
Menu Language  English, Spanish and French 
Remote Control  Yes
Power   
Power Requirements  120 VAC @ 60 Hz 
Power Consumption  385 W 
Energy Star Compliant  No 
General   
Dimensions (WxHxD)  44.8 x 29.6 x 1.4" (113.9 x 75.2 x 3.6 cm) 
Weight  125 lbs (56.5 kg) 
FCC Regulations  Class B (Home Use) 
Cabinet Color  Silver 
Warranty  1 Year Parts and Labor 


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