Friday, April 21, 2006
While digital TV offers a better picture than standard TV, mainly because it can display a greater number of vertical lines, a screen that can facilitate this display is required in order for the viewer to get the full effect of the image. This is also true of high definition television. A monitor that can handle the image is necessary, usually a 16x9 screen. Some HDTV screens are 4x3, and with this size, the programming you see will be reduced in size and presented in what‚Äôs called a letterbox format, with black bands at the top and bottom of the screen. Just because you‚Äôre watching a broadcast with a resolution of 1080i doesn‚Äôt mean you‚Äôll be getting the full effect if your TV isn‚Äôt big enough. For this reason, screen size is an important factor to think about when considering the purchase of a new set.
If your set isn‚Äôt big enough, the TV signal may be downconverted to suit the TV screen. The image will be sized to match the number of pixels in image. For instance, with an HD image of 1920x1080, the scale would be sized down to 1366 x 768, 1280 x 960, 1024 x 768, etc. The scaling down leads to diminishing image detail. Keep in mind when shopping for a high definition television that you need a set that can handle signals of 480p, 720p, or 1080i.
Televisions that can downconvert are called EDTVs, or enhanced definition televisions. An EDTV can read HDTV signals, but it has to downconvert the signal to an adequate resolution in order to display an image. Some plasma TVs are EDTVs and are more affordable. Video projectors that are ED are also more affordable. You can upgrade this type of projector so that it can handle HDTV by adding an HD connection.
Any television that can convert 1080i to 720p is considered an HDTV. In order to produce a full-fledged HD image, the TV or video projector must have a pixel resolution of at least 1280x720.
When shopping, don‚Äôt forget that resolution is expressed in terms of lines or pixels. Generally speaking, the higher the number of pixels, the better; this means you‚Äôll get a better picture. Other important considerations related to buying a TV include color quality, contrast ratio, viewing angles and brightness. The amount of space you‚Äôre willing to devote to a new set is also important, if you‚Äôre considering a widesceen set.