by Bill Elliott, HD Director of Photography

An advantage to either HDTV standard is the picture's rectangular shape. We refer to the width and height as the picture as its aspect ratio. Standard analog television of today was designed to display a 4:3 aspect ratio image. For instance, a screen 20" wide would only be 15" tall. This almost square image was decided on in the early days of television because it was the standard format used in motion picture films. The 4:3 film standard was created by W.K.L. Dickson in 1889, while working at the Thomas Edison Laboratory. While working on Kinescope experiments, he decided to make his film image 1" wide and 3/4" tall. In 1941 when the NTSC was deciding on a format standard for television, they had no reason to choose otherwise.

The A.T.S.C. adopted the 16:9 "wide-screen" aspect ratio as the standard for Digital-HDTV, because significantly more information can be displayed on the screen and it more accurately represents the aspect ratios used in modern motion picture production. The wide screen format is much closer to our eyes' natural field of vision. By more closely mimicking your eyes' field of view, it's easier for the filmmaker to bring the viewer into the action. Our vision is optimized within a 30-degree field of vision. We see details best within the 'center' area of this field, while our peripheral vision in the outer edges of this area is better at detecting motion. Thus the viewer's feeling of being there is enhanced. The old 4:3 aspect gives us the feeling of only being able to see within a 10-degree field of vision. A simple illustration of this is to cover one of your eyes. This is what 4:3 is like. Now remove your hand from your eye and experience 16:9!

On a high definition television set, when you view a motion picture that was filmed in one of the many wide screen film formats, you will see a screen that is filled with an image. You'll see the picture the way the director intended it to be seen. No longer will you be forced to watch a shrunken picture with black bars at the top and bottom or a "pan and scan" version of the program like you would experience with an analog 4 x 3 television screen. If you watch an older 4:3 aspect ratio movie on a new HDTV, you will however see black bars on each side of the screen. Some digital televisions have the ability to stretch old 4:3 pictures in order to fit them into the full 16:9 aspect HDTV picture. Stretching the picture causes it to become distorted. This feature can be turned on or off on most HDTV's. However it's important to note that just because a television can show a 16:9 image, that alone does not make it an HDTV, nor does the fact that it might be a digital picture. When selecting a new HDTV make sure it will reproduce a 1080i and/or a 720p digital HDTV picture without any additional accessories or modifications. Some unscrupulous sales people are offering add-on receivers that will down-convert an HDTV signal so it can be viewed on cheaper lower resolution screens.