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| High Definition Satellite TV Basics |
| What makes High Def so great? |
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Simply put, High-Definition is a video format that delivers the sharpest, clearest, television picture you've ever seen. A High-Definition (HDTV) picture is comprised of many more lines than a Standard Definition (SDTV) picture. The greater the number of lines the more detail the picture will have. HD broadcasts also have a rectangular shape, and feature Dolby Digital 5.1 Surround Sound.
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| Important Things You Should Know When Shopping For An HDTV |
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Even for those of us who love technology, getting bombarded by all the new terminology that usually goes along with it can get a bit annoying. When reading the specs on a new piece of hardware begins to sound like a foreign language, it's time to stop and get ourselves a quick education. The last thing any of us should do is jump to buy something that we don't really understand or know enough about. High-Definition equipment is not cheap, and knowing a little can save you a lot in the long run. You don't have to be an expert on HD to make a smart decision, but you do need to know the basics. So here they are...
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| What's an "HD Ready" TV? |
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This term has really confused a lot of people. Basically, when a TV is referred to as "HD Ready" it is physically capable of displaying a High-Definition image, however, it does not have its own integrated High-Definition tuner. This means that you will need to purchase a separate HD Tuner to receive and send the signal to the TV. In this scenario, the TV is acting souly as a display monitor, like the one connected to your computer. Some people don't mind this, as it allows them to mix and match components for higher overall quality. If you're a satellite subscriber, you will be using a separate HD Satellite receiver compatible with your provider's system. In this case "HD Ready" may be a smarter choice since you won't be paying extra for an integrated HD Tuner that you will not need.
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| HD Picture Resolution |
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Scan Lines: A TV picture is a lot like a Monet painting, up close it looks like a confusing mess of crap, but back up a few feet and you'll be viewing a masterpiece. If you've ever taken a really close look at the screen of your TV, you can actually see that the picture is made up of individual lines running in a horizontal direction across the screen. These are called Scan Lines. The number of scan lines contained in a normal TV broadcast is 525, but only 480 are used to make up the actual picture that you see. Generally speaking, the greater the number of lines, the more detail the picture will have. This is where HDTV gains its huge advantage over SD (Standard Definition). A High-Definition (HD) signal is comprised of 720 or 1080 lines of resolution as compared to just 480 lines for Standard Definition (SD). But as you'll soon see, lines are not the only factor in determining a picture's clarity, the way the lines are drawn on the screen is equally important.
Interlaced vs. Progressive Scan: The lines can be drawn across the screen using two methods, Interlaced or Progressive. Interlacing (i) requires two separate passes across the screen to display the picture. The picture's lines are broken up into 240 odd and 240 even rows, and each row is drawn on the screen in a separate pass. In essence you are only seeing half the picture at a time, but the TV draws the lines so quickly that your eye perceives the image as complete. The second method, known as progressive scan (p), draws the entire picture in one pass. The computer monitor you are reading this page on is progressive scan. Progressive scan is superior to Interlacing, as it produces a smoother, flicker free image. A HIGH-DEF image can be either Interlaced at 1080i (1080 lines) or Progressively scanned at 720p (720 lines).
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| Aspect Ratio |
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The shape of your television's screen determines its Aspect Ratio. Aspect Ratio is a term used to represent the ratio between your screen's horizontal and vertical measurements. Modern TV sets are available in two aspect ratios, 4:3 or 16:9. If you think of the screen size in inches, then a screen having a 4:3 aspect ratio is 4 inches wide and 3 inches high (kind of square). Similarly, a screen with a 16:9 aspect ratio will be 16 inches wide and 9 inches high (more rectangular). You don't really have to worry about this one too much since all HDTV's have a 16:9 aspect ratio. This ratio was chosen for HD because the rectangular picture closely relates to our normal field of vision, making the image much more pleasing and enjoyable to watch. Though 16:9 is the standard aspect ratio for HD, the motion picture industry rarely uses this format during movie production. Most movies are shot in even wider aspect ratios, which will still result in the display of black bars on the top and bottom of the image, even when viewed on a 16:9 HDTV. Hollywood just insists on being different I guess, and know one is going to change that.
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| Sounds That Match The Image |
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With all this talk about picture quality, it's easy to overlook the sound that accompanies HDTV. The standard audio format for HDTV is "Dolby Digital AC3". This is a 5.1 channel Surround Sound format that can easily turn your living room into a full blown movie theater. With Dolby Digital you have 5 main speakers, a Center Channel speaker responsible for delivering most of the movie's dialog, accompanied by a pair of Front speakers, and a pair of Rear speakers). The .1 in 5.1 refers to a separate Sub woofer channel that provides the all important movie theater BASS! If you don't have a separate audio system, you can choose to buy a TV that already has a Dolby Digital decoder in it. If you plan on using your AC3 equipped audio system then this won't really matter much to you.
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| Connection Methods |
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Since you'll be relying on an external Satellite Receiver to supply the HD signal to your TV, the way in which that signal is delivered can be one of the most vital areas of concern when purchasing HD equipment. You must always keep in mind that HD pushes video to the max, and therefore the quality of the signal delivered to your TV will have a much greater affect on the image than with SDTV. Cables and connection methods are often overlooked by most consumers since their differences are usually detected only by those with highly trained eyes.. This is not so with HDTV.
Know Your Display Type: First things first.. You must know what type of display you'll be using before you can decide on connection methods. Plasma's, LCD's, and DLP's, are all Digital displays, while CRT's are Analog. Keeping the digital HD signal in its native digital format (no digital to analog conversion) will almost always result in a better picture. Therefore the type of connection you choose should limit this conversion process as much as possible.
VIDEO Connectors: (Analog vs. Digital) Up until now the most common connection method has been "Component Video". This type of connection is analog, which means that the signal needs to be converted from digital to analog for transmission. It uses 3 separate cables to send the video signal to your TV. Component connections are acceptable for HD, but the conversion will ultimately result in slight signal degradation. However, if you have a CRT Display, using component will prevent having to convert the signal back to digital once it reaches your TV. The second method is DVI (Digital Visual Interface). You may be familiar with this type of connection because it is often found on many higher-end computer monitors and video cards. This is the preferred method by which to connect your digital HD components to your digital display, since it has extremely high bandwidth, and will also keep the signal in its native digital format. There is a noticeable increase in picture quality when viewing HD material via a DVI Connection.
AUDIO Connectors: (Optical vs. Coax) The Dolby Digital audio that accompanies an HDTV signal can be carried by either an Optical or Digital Coax cable. Optical cables have an advantage because they are not affected by electromagnetic interference, and are capable of running over longer distances without degrading.
VIDEO/AUDIO Connectors: You may have begun to hear a lot about HDMI (High-Definition Multi-Media Interface). HDMI is a connection method similar to DVI, but goes one step further by carrying both HD Video and Audio over a single cable. This will prove to be very popular as it greatly reduces the cost and complexity of connecting HD components together. HDMI is supported by many new products, and is currently available on HD Satellite Receivers from DirecTV and DISH Network.
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