For most of the last 50 years, it was much simpler to purchase a television and enjoy the available programming. In fact, in the early days of television all you had to was plug the set in (and pull up the rabbit ears) and enjoy yourself. Anyone could do it. Today there are so many industry acronyms and abbreviations to wade through: SDTV, EDTV, HDTV, 480i, 480p, 525p, 720p, 1080i, native display, aspect ratio, letterbox, analog, digital, progressive scan, interlaced, non-interlaced, composite video, component video, and DVI. Then there are different display devices like plasma, LCD, DLP, LCOS! And what, you may wonder, is the difference between a television and a monitor? It's enough to make your head spin.

But even if you purchase the right product but don't have the right signal, you may not be getting true high definition. So let's start at the beginning and see if I can help demystify television so that you can soon start enjoying WFTV in full HD splendor. Americans own almost 300 million televisions, and they all work basically the same way. A video signal arrives at the television, either through an antenna, cable, or satellite dish. The signal is made up of a series of still pictures called frames that are viewed at the rate of 30 per second. Each video frame contains 480 lines of information, which are scanned from top to bottom onto the screen. Odd numbers lines are scanned down first then are interlaced by the even number scanned up. This technique is known as "interlacing" and is used on 99% of the televisions currently sold in the US. Today, most of the TV's sold are still CRT based (cathode ray tube) and require an additional 45 lines of information, giving us a total of 525 lines. This format is also known as 525i and is the standard adopted in 1953 for all of over the air US broadcasting and became known as the NTSC standard (National Television Systems Committee).

Once Americans decided to bring the 'big screen' into their homes the trouble started. The NTSC standard was adopted when screen sizes were below 19 inches. But once pictures were blown up to 50 or more inches, the format's shortcomings (jagged lines, video noise, and scan lines) became visible, and the public wasn't satisfied. Virtually every big screen TV sold in the last 20 years was made from three CRTs (also called guns - red, green and blue), mounted in a box that project an image onto a fixed screen. In order to have a big, clear picture to display; they had to eliminate the scan lines that resulted from a non-interlaced signal. Eliminating the retrace from an NTSC signal and progressively scanning all of the lines in one sequential trace from top to bottom did help solve the problem. This was known as non-interlaced or Progressive Scan, which some refer to as 525p but is also known as 480p or Enhanced Definition Television. The performance of an EDTV set gets the viewer closer to High Definition performance.

The original format selected for television broadcasting was a 4:3 screen aspect ratio. Aspect ratio is the numerical relationship of the width to the height of a TV screen expressed as a ratio. Unlike the diagonal measurement used to determine a TV's screen size, 4:3 is 4 units wide to 3 units high that creates the traditional "square" that we think of as the TV picture. The movie industry used wider aspect ratios to enhance the theatrical experience. Films such as Ben-Hur and Lawrence of Arabia were filmed in very wide screen formats. Of the 18 wide-screen formats, the 16x9 aspect ratio became the High Definition broadcast standard. You have already experienced this wide screen format on your regular TV when viewing movies in letterbox, with those annoying black bars above and below your picture.

So now you have the basics! Next month I'll explain what makes HDTV so special!

This article was written by Charles O'Meara, Jr., President & CEO of Absolute Sound, Inc. in Winter Park, FL - an authorized LG dealer.