The Ten-Minute Guide to HD: High Definition Video

Any consumer who has purchased multimedia equipment in the last five years has no doubt been barraged with a variety of terms; from HDMI to Bluray, LCD to DLP -- it seems that the entire industry operates on acronyms alone! Fortunately, understanding the HD market doesn't have to be complex. This article will guide you through the basics of high definition video.

First, there're displays (i.e. the TV itself). Most consumer displays are of one of three types: LCD, Plasma, or DLP.

• LCD displays use a technology called Liquid Crystals -- these are the same type of displays that have been used in laptops for years. These displays (typically only a few inches thick) provide a bright, clear picture -- but their main advantage is their cost; an LCD display costs anywhere from 25 to 50 percent less than an equivalent plasma display.
  
  
• Plasma displays match LCD displays in terms of size (they're usually about the same thickness) but surpass them in terms of image quality, especially since these displays often feature a very high contrast ratio. The practical upshot? A plasma display will have blacker blacks, redder reds, and a more lifelike color balance. Image clarity is generally the same as with an LCD display of the same resolution. Plasma displays tend to run a few hundred dollars more than their LCD counterparts.
  
  
• DLP displays provide large screen sizes at good prices, but do not provide the same contrast ratio, color balance, or viewing angle that LCD/Plasma displays do. As LCD technology continues to drop in price, these displays are becoming less and less common, although it's still quite common to find DLP displays in the 40-60 inch range, particuarly if you're looking amongst the budget models. This technology will most likely fade away over the next few years, although it's likely to be found in cheaper displays for a while (at least until LCD screens come down in price.

HD displays can display high-definition content -- but where does that content come from? There are a variety of high-definition content sources out there.

• A common source of high definition content is HDTV. While HD channels may not be available in your area yet, it's worth a call to your cable/satellite company; there has been a tremendous increase in the market penetration of high-def TV in the last couple years, and more and more providers are offering HD content to their subscribers.
  
  
• BluRay and HD-DVD also provide high-def content. The industry is currently divided over which of these two competing formats will be the eventual "format of choice", but a fair number of movies are available for each disc type -- and both make for an excellent high-def experience. Most consumers will probably continue to watch their movies on DVD though, at least until the price for players and discs come down.
  
  
• Game consoles (such as the XBox 360 and PlayStation 3) can support high definition displays. Most releases for the XBox 360 and PlayStation 3 take advantage of the consoles' ability to output high definition content, resulting in a far more movie-like gaming experience. Be forewarned though: not all games output true HD, so the quality of the resulting image may vary from game to game.
  
  
• From a PC, via a device such as the AppleTV. The AppleTV enables users to stream video from their computers to their televisions (high-def and otherwise), allowing them to watch their downloaded media without squinting at their monitors. Such a device not only increases the usefulness of the family PC, but also allows media to be kept somewhere other than "in a stack next to the DVD player".

We've covered HD content, and we've covered HD displays -- that leaves one component to cover: connections. HD devices can be hooked up in a variety of ways:

• DVI - Digital Visual Interface This connection uses a single cable to carry all video data. Since this is a digital connection, it can carry a full HD signal with no loss in quality. Since it doesn't use any sort of DRM (digital restrictions), you don't have to worry about device incompatibilities, etc. As such, DVI is the technology of choice when connecting HD equipment.
  
  
• HDMI, or High-Definition Multimedia Interface On a basic level, HDMI is similar to DVI. Unlike DVI, it also can carry an audio signal on the same cable, so devices that can use HDMI are usually pretty simple to set up. On the downside, it supports DRM -- technologies which can severely limit your ability to use content as you wish. (Imagine spending $2,000 on a TV, only to find out that your shiny new Bluray player won't speak to the TV because the manufacturers don't consider it to be a "trusted" device. That's actually happened to some users...) Other than that, Ms. Lincoln...
  
  
• Component video Component video separates the video signal into three channels (brightness [or luma], red, and blue). The video is sent over three cables, one for each part, using analog transmission; component is the only one of the three main connection technologies to use analog transmission. While this does mean that low-quality cables are more likely to exhibit interference, it also means that interference will not necessarily interrupt the display of the video signal -- just that the displayed image may exhibit visual noise. (In contrast, noise in a digital signal often prevents the image from appearing whatsoever.) Component video is often found on older (prior to 2002) equipment, and is gradually being phased out in favor of digital connections such as DVI and HDMI.

And that's all there is to it. Three main types of displays, four sources of content, and three ways to hook the former to the latter. If you're looking for more information on the HD revolution, feel free to check out the sequel to this article, where I'll be going into more detail about HD (as well as explaining the various audio options for your HD experience.)