Some HDTV's displays have a more limited viewing angle than others. They lose contrast and become hard to read at some viewing angles and they have more contrast and are easier to read at others. Generally the higher the viewing angle, the better. This is especially important when a group of people are watching an HDTV at the same time. Modern High Definition TVs have much better viewing angles, and it is not as big an issue as it was in the past.

This is the difference in light intensity between the brightest white and the darkest black. Higher is better. The higher the contrast ratio, the greater the ability to show subtle color details, and better resulting picture. Details in dark scenes will benefit from a higher contrast ratio. Many manufacturers give what is called Dynamic contrast which is a higher number than the contrast ratio. So be careful not to confuse this when comparing. LCD panels regular contrast ratios hover around 1200-1400 to 1. Dynamic can run as high as 15,000 and more. As noted one must consider both static and dynamic contrast ratios.

For LCD TV's. Response time is in simplistic terms how fast the screen can "paint" the screen. It is measured in milliseconds or (ms). Lower numbers are better. A lower response time is best for games, video, fast moving movies. Today's HDTV's have much faster response times than in the past and this issue is also becoming less important since most models today are quite fast.

Introduced in Mid 2007, a new type of LCD HDTV technology has come out on select HDTVs. 120hz refers to the frame rate of an HDTV. Currently sets are 60hz. The double frame rate 120hz sets will make fast action less prone to blurring. This is important for action movies, and sports. Plasma HDTVs do not need this technology as they handle fast action without the need for 120hz. Smart-Review will feature these sets as they become available. Samsung 120hz HDTVs

Most of the newer HDTVs now include a digital HD tuner called ATSC. An ATSC digital tuner is required to receive and decode over-the-air digital television signals. Sets do not require this tuner if you are only receiving your high definition feed from a cable company or from satellite, as they will provide you with a high definition decoder box instead. This gives you the option to receive "free" over the air HD local broadcasts.

- Some newer HDTVs have not only ATSC, but also a QAM tuner. An integrated QAM tuner allows the free reception of unscrambled digital programming sent "in the clear" by cable providers (without a box), usually local broadcast stations. This varies by cable company. Most other stations however are scrambled.

- Some sets allow you to put a Cable Card in a slot. This card is provided by your cable tv company and allows you to descramble the channels without a cable box. Some people would rather not rent the box provided by the cable company. However, you may lose the TV schedule and on demand features when you use this feature instead of the provided box.

HDTVs come in a variety of sizes. They come as small as 19 inches and up to 60+ inches. As a general rule, the smaller the room, the smaller the TV. A bedroom should do well with a 26-32 inch HDTV, although there is no set rule to this. A living room depending on the size should be in the range of 40 inches and higher. Those with larger living rooms may need a larger TV. Click on the Amazon HDTV Sizing Guide for more information on HDTV sizes.