Defining High-Definition
Aspect Ratio
In addition to resolution and interlacing, a television picture is also defined by the aspect ratio of its broadcasts—referring to the shape of the screen as defined by the ratio of the screen’s width to its height.
For analog TV, the aspect ratio is 4 units wide by 3 units high (usually written 4:3). This is the familiar shape of conventional TVs—slightly wider than they are tall. SDTV and EDTV can be either 4:3 or 16:9. For HDTV broadcasts, the aspect ratio is 16:9—nearly twice as wide as it is tall. This is, not coincidentally, more like the shape of movies shown in theaters, which makes HD an ideal format for viewing movies on TV.
Screen Formats
What if you’re watching a nearly square-shaped 4:3 broadcast on a 16:9 TV, or vice versa? The DIRECTV HD Receiver lets you choose from a variety of screen formats to deal with those scenarios. You can set up your preferences for format during guided setup. You can change these settings at any time.
See the next page for your options.