Monday, April 1, 2013
Before You Buy an LCD TV
By Robert Silva
Flat panel televisions are quickly becoming quite commonplace on store shelves and in consumers' homes. LCD flat panel televisions, with their decreasing price points and performance improvements are becoming a very desirable alternative to the standard CRT set. However, before you jump at the latest "great ad deal" on an LCD flat panel television, there are some useful tips to take into consideration on what to look for when buying an LCD TV.
Find a place to put your LCD TV
Since LCD TVs are very thin, they can be either wall or table mounted. For a wall mounted LCD TV, avoid placing over a functioning fireplace. The heat from the fireplace may affect the performance and longevity of the set. If you are using the provided table mount, take a tape measure to the dealer with you so you can make sure that the entire width of the set will fit in your space. Make sure you leave one or two inches on each side, the top, and back, for ventilation and connection access.
Native Pixel Resolution
LCD flat panel sets have a fixed number of pixels on the screen surface. The key is to get as high a native pixel count as possible. Most LCD TVs 23-inches and up in screen size offer at least a 1280x720 (720p) or 1366x768 (768p) native pixel resolution. These are the minimum pixel counts you should look for in an LCD television.
In addition, most larger screen LCD TVs (especially those 40-inches and larger) now offer 1920x1080 (1080p) native pixel resolution, which is even more desirable, especially if you have, or plan to purchase a Blu-ray Disc player.
Scaling
Scaling is a process where a television's video processor will match the resolution of the incoming signal to its native pixel resolution. This means that lower resolution signals will be upscaled, but the processor will downscale higher resolution signals so that they can be displayed at the TVs native resolution.
Poor scaling can result in artifacts, such as jagged edges and inconsistent detail. It must also be noted that results also depend on the quality of the incoming signal.
Motion Response Time
The ability for an LCD TV to display fast moving objects has, in the past, been a weakness of LCD technology. However, this has improved dramatically. This does not mean that all LCD TVs are created equal in this area.
Check the specifications for Motion Response Time (ms = milliseconds). A good LCD TV now should have a Response Time of either 8ms or 4ms, with 4ms being optimum, especially if you watch lots of sports or action films. Be wary of LCD TVs that do not list their motion response time.
Contrast Ratio
Contrast ratio, or the degree of variation of the whitest and darkest parts of the image, is a very important factor to note. If the LCD TV has a low contrast ratio, dark images will look muddy and gray, while light images will look washed out.
Also, don't get seduced by Contrast Ratio marketing hype. When checking contrast ratio numbers, look for Native, Static, or ANSI contrast, not Dynamic or Full On/Full Off contrast. ANSI contrast represents the difference between black and white when both are on the screen at the same time. Dynamic or Full ON/OFF contrast only measures black by itself and white by itself.
Brightness
Without sufficient brightness your image will look muddy and soft, even in a dark room. Viewing distance, screen size, and ambient room light will affect the need for more brightness capability.
A brightness rating listed as 550 cd/m2 or higher is good, however, don't get bogged down with the technical number listed, just make sure the screen is bright enough for your needs upon your own visual inspection.
Viewing Angle
Make sure you can view the image on the LCD TV from the sides as well as the from the prime viewing area. LCD TVs typically have a good side-to-side viewing angle, with many going as wide as 160 Degrees, or about 80 degrees from the center viewing spot.
If you find that the image begins to fade or becomes unviewable within 45 degrees from either side of the center viewing spot, then it may not be a good choice where you have a large group of viewers sitting in different parts of the room.
Tuner and Connection Considerations
Almost all LCD-TVs now have both built-in NTSC and ATSC tuners. An ATSC tuner is required to receive over-the-air TV broadcast signals after June 12, 2009. Also, some LCD TVs have what is referred to as a QAM tuner. A QAM tuner is what is required to receive unscrambled HD-Cable programing without a cable box.
Credit : about.com
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