Four styles of HDTV

Once upon a time, when only analog, tube TVs were around, buying a new set used to be a whole lot less of a nerve-racking experience. Now, there are all sorts of questions. Do you go wide or not? Is LCD better than plasma? And what's the difference between rear-projection LCD, LCoS, and DLP HDTVs? If all the tech jargon has you confused, don't worry. Read our guide to the pros and cons of high-tech TVs, and you'll feel a whole lot more confident when you hit your local electronics store.

Direct-view (tube) TVs

Direct view is how industry insiders refer to any television that doesn't use projection technology. Many of them are the familiar tube TVs you see everywhere--they're called tubes because the glass forms the business end of a cathode-ray tube (CRT). Direct-view tube TVs can be found in sizes up to 36 inches (diagonal), and as their screen sizes increase, so do their heft and depth. Sony's 34-inch KD-34XBR960, for example, tips the scales at nearly 200 pounds, measures 24 inches deep, and requires a minimum of two--and probably three--burly guys to lift it onto a stand. Because of size and weight issues, it doesn't pay for companies to make larger tube TVs; they simply aren't practical.

High-end tube TVs can give a great-looking picture. CRTs are still the kings of black level, a term used to describe the quality and the depth of black, the darker the better. Direct-view tube sets look good from any angle, so unlike flat-panel LCDs and rear-projection sets, the picture quality doesn't change depending on where you sit. Compared with newer TV technologies, however, direct-view sets often look softer with high-definition material because they can't deliver as much detail. Most tubes won't accept high-resolution PC sources. Also, tubes suffer from more geometry errors than do flat-panel sets, which can make straight vertical and horizontal lines appear to bend onscreen.

New developments

Flat vs. curved screens: The traditional curved shape of the glass tube is giving way to completely flat glass. Sony introduced flat tubes first with its Wega televisions, but now, just about every manufacturer sells some kind of flat-tube TV. Flat glass not only looks more high tech, it collects less ambient light from the room and, therefore, helps to reduce glare. But it's a myth that flat tubes result in straighter lines; they can have the same geometry problems as their curved counterparts, especially near the corners and the edges of the screen.

Digital vs. analog: Many tubes are still entirely analog, meaning that they won't work with high-definition tuners or progressive-scan DVD players. An increasing number of direct-view tube TVs, however, can display high-definition sources. These sets still use the tube, an inherently analog display technology (unlike plasma, LCD, DLP, and the rest; see the following sections), but if they can accept and display high-definition and progressive-scan images, they qualify as honest-to-goodness HDTVs.

Wide-screen 16:9 vs. standard-screen 4:3: For the strongest theatrical impact, the majority of movies and HDTV shows are filmed in the wide-screen format, where the screen is much wider than it is tall. Regular televisions and most standard-definition TV programs use a narrow-screen, 4:3 aspect ratio, which refers to the width of the screen compared to its height. Newer TVs--especially HDTVs--almost always have screens with a much wider ratio: 16 units of width for every 9 units of height, which translates to a 16:9 aspect ratio. Wide-screen, direct-view TVs cost more than 4:3 models for the same amount of screen real estate, but they're great if you watch a lot of DVDs or HDTV.

Thin tubes: Some TV makers are coming out with so-called thinner tubes that are much shallower than standard tubes of the same size. Samsung's TX-R3093WH is a good example: its depth measures just 16 inches, which is about 6 inches shallower than a typical 30-inch wide-screen tube TV. While that depth is definitely thinner than usual, it's certainly not flat.


Source: http://www.cnet.com/4520-7874_1-5108443-1.html?tag=txt