Lighting Source

• For an image to appear on an LCD screen, lighting is channeled through optical filters behind the screen. There are two types of lighting sources for LCD high-definition TVs: fluorescent bulb and LED-backlit. Fluorescent lighting was used on the first LCD televisions and is still the dominant form of lighting; however, LED-backlit LCD screens are more energy efficient and provide better viewing quality through a technology known as local dimming.
  
  

Screen Resolution

• LCD televisions are commonly available in two resolutions: 720p and 1080p. With a screen resolution of 720p, 720 lines of progressive video are shown on each frame. With a screen resolution of 1080p, 1080 lines will be shown on each frame. Screens with a resolution of 1080p produce the best image quality, especially when being viewed at close range.
  
  

Contrast Ratio

• The contrast ratio of an LCD television compares the brightness of the white the screen produces to the darkness of the black the screen produces. Higher contrast rates make for better image quality. However, these ratios are determined by the manufacturer's own tests and are not a very useful means in determining the overall quality of the television. To determine the best LCD television, compare how the screen produces video black. The highest-quality LCD televisions produce the deepest, darkest blacks.
  
  

Response Times

• Response times in an LCD television refer to the speed at which the pixels change on the screen. The best LCD televisions have the lowest response times. Televisions that have high response times can have a problem with images blurring because the pixels do not change fast enough. This is particularly noticeable when viewing something moving fast, such as sporting events or action movies. A response time of 8 milliseconds or less produces the best playback of images.
  
  

Viewing Angle

• When viewing an LCD screen head on, the image on the screen will appear clear; however, when viewed from side angles, the visual performance suffers. The viewing angle of an LCD television refers to the maximum angle that the screen can be viewed from without compromising image quality. Horizontal viewing angle is the most important consideration for most home-theater setups. The best LCD televisions have the highest viewing angles.