By Bob Gatton
Only a few years ago choosing a television set, or display, was a relatively simple process. The main two choices were the traditional glass CRT (cathode ray tube) set or, if you wanted a larger set, a rear-projection television that used three small CRTs to produce the picture. Both types of displays produced a picture that was nearly square.
While CRT-based sets remain popular, they have been joined by newer technologies.
- LCoS (liquid crystal on silicon; pronounced L-coss) and DLP (digital light processing) are used for projection TV
- Plasma, used on flat-panel displays
- LCD (liquid crystal display), used on both projection and flat-panel displays
Televisions are also getting wider. Sets of the past had 4:3 screen ratios–they were four units wide by three units high. Newer displays are 16:9 -- sixteen units wide by 9 units high. These are referred to as widescreen televisions.
There are three main reasons for the migration to widescreen displays:
- More TV programming and the majority of movies are proportionately much wider than a 4:3 display.
- The High Definition Television standard defined by the Advanced Television Standards Committee specifies 16:9 displays.
- It's the way we see; widescreen televisions are more compatible with the way the human eyes works. Our field of vision is much wider than it is high.
Analog vs. digital, standard vs. HD
Analog televisions have served us well for many years, but digital televisions deliver crisper, more detailed pictures. There are three quality levels for digital TV:
Good: SDTV or standard definition television. The same resolution as the analog television standard, but can be broadcast digitally.
Better: EDTV or enhanced definition television. Once again, the same resolution as analog TV, but information is "painted" on the screen more quickly. The result is a much smoother picture, especially during scenes with motion.
Best: HDTV or high definition television. The two most common specifications that indicate a set is a high definition TV are 720p and 1080i. A quality HDTV connected to an HD source produces an amazingly detailed, high-quality picture.
Plasma and LCD televisions are only a few inches deep. They have become extremely popular in the last few years. While both are more expensive than traditional CRT televisions, they are rapidly becoming more affordable.
Their thinness opens up a variety of new installations options besides the obvious one, hanging the set on the wall. You can put a small LCD television under the kitchen counter and have it pivot up, out of view when it is not being used. Several companies make articulating arms, these let can pivot the set so it can be viewed anywhere in the room. The next step up is to use a motorized lift to retract the televisions into the ceiling or a piece of furniture when not in use.
Until recently, LCDs were smaller televisions, plasma televisions were larger, but that is changing quickly. Both Samsung and Sharp have announced plans for 65" widescreen LCD televisions. But the majority of LCD televisions sold are 37 inches or less; the majority of plasma televisions are 42" and larger.
Which is better? Both technologies have their own strengths, but both are capable of producing very high quality picture which will provide many years of enjoyment.
One word of caution: Most plasma displays will not operate properly at elevations higher than approximately 5,500 feet above sea level. To put this into perspective, Denver is just under the limit, but Vail, Aspen and Sante Fe are not. If the house is at high altitude, check the specifications for the particular model you are considering.
See all articles in the Home Theater/Media Room Series
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