When a film is cropped to fill the 4:3 aspect ratio of an analog TV, important action on the right and left sides of the picture is lost. Analog TVs sometimes accommodate a film's original format by utilizing the entire width of the screen while displaying black bars above and below the picture to fill the extra space, a feature known as letterbox format. Virtually all DVDs and some videocassettes offer this viewing option.

Horizontal Scan lines
Scan lines refer to horizontal slices of a TV picture that are scanned onto the screen, one line at a time, to form a complete image. The picture on an analog TV is made up of 480 horizontal scan lines* that are painted and repainted in rapid succession, creating the appearance of fluid motion. While the technology for utilizing a higher number of scan lines (and achieving a clearer picture) has existed for decades, much of the world has been limping along with the original color broadcast standard established by the National Television Standards Committee (NTSC) over 50 years ago. After years of waiting, HDTVs finally provide the ability to display images with higher numbers (720 or 1080) of horizontal scan lines.

Interlaced vs. Progressive
The resolution of new TV monitors are usually described as "480i", "480p", "720p" or "1080i".** The "i" or "p" following number of horizontal scan lines refer to interlaced and progressive methods of scanning. If a television utilizes interlaced scanning, the lines that make up the picture are generated in alternating odd/even fashion, with the odd numbered lines being painted first (1,3,5,...) and then the even lines (2,4,6,...) following. At 30 frames per second, the whole process happens so quickly as to be imperceptible.

With progressive scanning, the lines on the screen are painted in order (1,2,3,4, etc.), with the entire frame being generated at once - the same way that pictures are scanned on a computer monitor. A full video frame is repainted every 1/60 of a second, providing a superior picture free of flickering and other motion artifacts. Only digital broadcasts and sources such as progressive scan DVD players provide a signal that will support this method of scanning.