High-definition video

High-definition video


High-definition video or HD video generally refers to any video system of higher resolution than standard-definition (SD), which includes NTSC and PAL. Original HD specifications date back to the early 1980s, when Japan experimented with a 1025-line TV standard. Japan presented their parameters at an international meeting of television engineers in Algiers in 1981 and Japan's NHK presented its analog HDTV system at Swiss conference in 1983

High-definition signals require a high-definition television or computer monitor in order to be viewed. High-definition video generally has an aspect ratio of 16:9 (1.78:1). The aspect ratio of regular widescreen film shot today is typically 1.85:1 or 2.40:1. Standard-definition television (SDTV) has a 4:3 (1.33:1) aspect ratio.

High-definition television (HDTV) resolution is 1080 or 720 lines. In contrast, regular digital television is 480 lines (NTSC-like) or 576 lines (PAL/SECAM-like). Current DVD quality is not high-definition, though high-definition disc systems like HD-DVD and Blu-ray are expected to be released in 2006.

HDTV resolutions

To take full advantage of HDTV, you must find an LCD, plasma, CRT, or DLP device that has a native resolution of either 720p (1280 × 720 pixels: 720 lines progressively scanned with a widescreen 16:9 aspect ratio) or 1080i (1920 × 1080: 16:9 widescreen image with 1920 pixels across each of 1080 interlaced scan lines). These are the only two HD formats defined by the U.S. HDTV standard (ATSC). All network broadcasters use one or the other for their HD programs. For instance, ABC and Fox broadcast in 720p, while CBS, NBC, and PBS use 1080i. Likewise, cable and satellite networks will use one or the other: HBO, HDNet, Discovery HD Theater, and Showtime use 1080i, whereas ESPN uses 720p. Broadcasters choose one or the other for different reasons. Progressive scanning (720p) produces a smoother, more film-like look, but a 1080i image actually contains greater detail. Though it has fewer lines, the native progressive scan format (720p) eliminates motion artifacts that originate in interlacing. For subject matter that contains a lot of rapid motion—football, basketball or hockey games, for example—720p will produce a clearer, more stable picture than 1080i. Alternatively, for subject matter that has very little motion, 1080i is capable of rendering more picture detail. And because 720p has the highest data bandwidth and horizontal scan rate, it usually means that 720p programming is converted or scaled to 1080i for transmission (it occupies less digital "space" than 720p).

Movies that have been shot in HD

Arguing that film is not high quality enough to make movies (in part because of poor film development processing, poor monitoring system, and a general inabilty to see what the camera is actually capturing) and the increasing usage of computer generated, augmented or edited picture sequences has led some directors to engage in shooting their movies using the HD format via high-end digital cameras. Some examples are George Lucas and Robert Rodriguez.

Many television shows with science fiction themes and special effects (like Enterprise or Stargate) have also begun to use digital cameras.

Movies that have been shot on HD digital video include:


  • Star Wars Episode II: Attack of the Clones

  • Star Wars Episode III: Revenge of the Sith

  • Spy Kids 2: The Island of Lost Dreams

  • Spy Kids 3-D: Game Over

  • Once Upon a Time in Mexico

  • Sin City

  • Sky Captain and the World of Tomorrow

  • Russian Ark