Just because a television is digital, does not necessarily mean that it offers true HD. The FCC has mandated that all televisions eventually switch from analog to digital so eventually everyone will need a digital set to watch TV. If you’re going to invest in a new television and are considering getting a standard definition digital set, be aware that this does not mean high definition. Now: here are the critical differences in the three levels of digital television.

SDTV: Better Than Regular TV

Standard Definition TV broadcasting has eliminated those annoying "ghost" images and "snow" sometimes seen in analog broadcasts. SDTV's picture resolution can range from about the same as analog TV to about twice the resolution-a noticeable improvement. The audio is digital, too, so the sound is of higher quality than on analog TV (like a CD compared to FM radio) and can even feature multiple channels of surround sound.

EDTV: Really getting good

The next level of digital television is Enhanced Definition TV, EDTV. EDTV features a minimum of 480p scanning lines, for a more detailed picture than SDTV. You can see the difference. EDTV also can reproduce Dolby® Digital audio.

HDTV: the best you can get

HDTV has all the benefits of EDTV, but goes far beyond it in picture resolution and audio features. The HDTV specification requires a minimum of 720 horizontal scanning lines, far higher than EDTV and about five times the resolution as analog TV! It's a level of detail that you've never seen before.

Pixels

Another way to compare the two is by looking at their pixel count (pixel is short for "picture elements", the individually addressable areas of light and shadow on your screen). The 720p format creates an image with 720 lines, each with 1280 pixels, so it has a resolution of 1280 x 720. The 1080i format creates an image with 1080 lines, each with 1920 pixels, so its resolution is a higher 1920 x 1080. Denser pixels = a better picture.

When you're shopping for a new TV, remember this: at a minimum, an HDTV television-whether it's a projection television, plasma display, or traditional CRT type-must be able to display images at a minimum of 1080i or 720p. A "digital TV" or "digital-ready TV" or "EDTV-ready TV" that doesn't meet this spec cannot deliver HDTV! You would still get the improvement of digital TV over analog, but you wouldn't be ready for HDTV, which is the future of broadcasting.

You Can See the Difference

As we said, the HDTV difference is clearly visible. On the best sets, you will see details that you've never seen before on a television. Here are a few examples.

Actor's faces look more expressive and you'll see more detail in costumes and clothing.
When watching sports, you can follow the ball, the puck, or a racecar more easily and see subtle details in an athlete's movements, even the fuzz on a tennis ball.
A forest looks like a group of individual trees, not a brown and green clump.
Concerts in HDTV feature incredible visual detail and digital sound.
In short, everything looks and sounds far more life-like and more realistic. The first time you experience HDTV, on a true HDTV television and a good surround sound system, is almost unbelievable.

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