LCD TVs are now in vogue in India. Everybody desires one and even middle class families have started to buy them to replace their old CRT TVs. However the biggest challenge that is being faced by the buyers, is the selection of the right make-model. Hundreds of models are on display, but not enough technical / testing information is available and unscrupulous dealers are more than happy to palm off their defective wares on to the unsuspecting customers.
Here’s a quick guide to help you decide and purchase the right LCD TV for your home/office. Evaluate the LCD TV you intend to purchase against the following parameters.
1. Screen Size
Determining the right screen size is quite easy. It’s mathematical, hence precise.
1a. By Viewing Distance
To decide the screen size based on your viewing distance, multiply the distance (in feet) with 4 to get the screen size (in inches). For example if your sofa is 8 feet (96 inches) away from the TV, you need a 32 inch TV (8 x 4 = 96 / 3). Corollary, to determine the optimum viewing distance for your TV, divide the screen size (in inches) by 4 to get the viewing distance in feet.
1b. By Image Size
LCD TVs (wide-screen, 16:9 ratio) are actually smaller than their CRT TVs (4:3 ratio) for the same diagonal screen size. When compared to a 32? CRT TV, a 32? Wide-screen TV is smaller by 11% & presents an image that is 33% smaller in area. Hence, if you are looking forward to maintaining the same image size while viewing, be sure to choose a LCD TV that is 1.22 times bigger. For example, if you had a 21? CRT TV, you need a 26? LCD TV. If you had a 27? CRT TV, you need a 32? LCD TV. If choosing a TV by image size, be sure to calculate the optimum viewing distance using corollary presented in (1a).
2. Gamma/Saturation
This is where subjectivity comes in. Gamma is amount of light being emitted by lit pixels. If the gamma is low, then image will appear dim. Dark areas will be nearly black and detail will not be visible. If gamma is high, the image will appear very bright. Bright areas may appear to be nearly white and washed out making it impossible to spot pale colors.
Gamma is different from brightness where the brightness of the dark areas in the image is controlled. Gamma is different from contrast where the brightness of the light areas in the image is controlled. More often than not, gamma is property of the image-panel rather than the image itself.
A simple way to check for good gamma is to look for an image that has both dark areas and bright areas. For example images shot on a bright day. On a good LCD TV, the dark areas of the image will look nearly black instead of gray and bright areas of the image will represent the color of the area rather than just white. For example, light blue sky versus white sky, dark brown furniture versus black wood.
In India, National Geography & Animal Planet transmit high quality images all day that are perfect for gamma testing. Look for vibrancy in blue skies, green grass & red flowers. Ensure that none of these color appear fluorescent or washed out.
Here’s a quick guide to help you decide and purchase the right LCD TV for your home/office. Evaluate the LCD TV you intend to purchase against the following parameters.
1. Screen Size
Determining the right screen size is quite easy. It’s mathematical, hence precise.
1a. By Viewing Distance
To decide the screen size based on your viewing distance, multiply the distance (in feet) with 4 to get the screen size (in inches). For example if your sofa is 8 feet (96 inches) away from the TV, you need a 32 inch TV (8 x 4 = 96 / 3). Corollary, to determine the optimum viewing distance for your TV, divide the screen size (in inches) by 4 to get the viewing distance in feet.
1b. By Image Size
LCD TVs (wide-screen, 16:9 ratio) are actually smaller than their CRT TVs (4:3 ratio) for the same diagonal screen size. When compared to a 32? CRT TV, a 32? Wide-screen TV is smaller by 11% & presents an image that is 33% smaller in area. Hence, if you are looking forward to maintaining the same image size while viewing, be sure to choose a LCD TV that is 1.22 times bigger. For example, if you had a 21? CRT TV, you need a 26? LCD TV. If you had a 27? CRT TV, you need a 32? LCD TV. If choosing a TV by image size, be sure to calculate the optimum viewing distance using corollary presented in (1a).
2. Gamma/Saturation
This is where subjectivity comes in. Gamma is amount of light being emitted by lit pixels. If the gamma is low, then image will appear dim. Dark areas will be nearly black and detail will not be visible. If gamma is high, the image will appear very bright. Bright areas may appear to be nearly white and washed out making it impossible to spot pale colors.
Gamma is different from brightness where the brightness of the dark areas in the image is controlled. Gamma is different from contrast where the brightness of the light areas in the image is controlled. More often than not, gamma is property of the image-panel rather than the image itself.
A simple way to check for good gamma is to look for an image that has both dark areas and bright areas. For example images shot on a bright day. On a good LCD TV, the dark areas of the image will look nearly black instead of gray and bright areas of the image will represent the color of the area rather than just white. For example, light blue sky versus white sky, dark brown furniture versus black wood.
In India, National Geography & Animal Planet transmit high quality images all day that are perfect for gamma testing. Look for vibrancy in blue skies, green grass & red flowers. Ensure that none of these color appear fluorescent or washed out.
6 comments:
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Nice Info.
Good information for us.
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