What's Your Type?

The television is one of the most significant inventions of the 20th century. For the whole picture, read How Television Works.

In the past few years, there have been tremendous leaps in TV technology. Twenty years ago, TV shoppers had very few choices. These days, several TV technologies are competing with one another. This makes TV shopping all the more difficult. Each TV type has strengths and limitations based on the technology being used. Deciding what type of TV is right for you starts with understanding the factors that affect a TV's performance.

Viewing range is an important factor, especially when shopping for a big-screen TV. The viewing angle represents the total area in front of the screen that the image can be seen without distortion. When it comes to viewing range, some TVs are better than others. This is based on the technology used to deliver the picture. For instance, because a plasma TV uses tiny lighted cells to produce the picture, if you are viewing these cells at an angle you will lose picture clarity. A traditional tube TV (CRT) uses a cathode ray to paint the screen with the picture. This method allows for a wide viewing angle.

Black level is your TV's ability to produce the color black. TVs create image color by mixing the colors red, green, and blue. Black is the absence of color and serves to provide detail to an image. Achieving a true dark black is something newer TV technologies such as LCD (liquid crystal display) and plasma are struggling to create. To this day, nothing beats an old-fashioned tube TV (CRT) for black level.

Resolution is the number of pixels per square inch. Pixels are tiny, colored dots that combine to form the picture you see on the TV screen. The more pixels there are on the screen, the higher the resolution. The higher the resolution is, the better the picture quality. Resolution measurements are shown in this type of format: 1280x720. These numbers correspond to the number of horizontal and vertical pixels in the image. To give you an idea of the available range, a CRT TV is capable of up to 480 lines of resolution, while an HDTV can produce 1920x1080. You may see resolution abbreviated to only the second (vertical) number, plus a letter "p" (progressive scan) or "i" (interlaced) -- so, 720p or 1080i.

Burn-in is the term for the damage done to a screen by static images that are displayed for a long time. Both tube TVs and plasma TVs are prone to this kind of damage. When a static image like a stock market crawler, station logo or video game score display is left on the screen for a long time, the image gets burned into the screen by the picture-producing mechanism. Burn-ins will appear as "ghost" images on a screen. The chance of burn in can be reduced on any type of TV by setting the contrast levels at their middle settings and making sure static images are not displayed on a TV for hours at a time. A new technology called auto pixel shift also helps plasma screens resist burn-in.

Glare is created when a TV screen picks up ambient light from the room and reflects it back at the viewer. This is a particular problem with tube TVs that have curved glass screens. To counter this, manufacturers provide flat-screen versions that drastically reduce glare. They are more expensive, but may be well worth the extra money if glare is a problem in your home.

Durability is a desirable trait in anything you buy. Once again, the technologies used are the greatest determining factor in the life span of your new TV. LCDs and CRT TVs are known for their long lives. On the other hand, plasma TVs and projection TVs have much shorter life spans despite their much larger price tag.

Price is an obvious factor when shopping for anything. In the world of TV shopping, price is stacked based on the size and type of television. Plasma and LCDs are more expensive than CRT TVs because the technology is newer and more expensive to produce. The most important thing to remember when TV shopping is that the highest price does not necessarily mean you are going to get the best picture.

Screen size is an interesting limitation that affects all types of TV. The limits are set based on the practicality of implementing a particular type of technology for the screen size in question. For example, a CRT tube TV gets taller and wider as the screen size increases. It also gets deeper and heavier in order to accommodate the larger tube needed to produce the picture at that size. CRTs top out at about 40 inches because any larger would make them impractical. LCDs, which are based on transistors and capacitors, suffer from a similar limitation but for a different reason -- increasing size beyond about 37 inches produces a display that is too likely to contain a bad transistor. Plasma TVs and projectors, on the other hand, really have no limit to screen size other than the price.