Anamorphic widescreen
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Anamorphic widescreen (also called full-height anamorphic or FHA) is a process by which a comparatively wide
The technique comes from cinema, when a film would be framed and recorded as widescreen but the picture would be "squashed together" using a special
The optical scaling of the lens to a film medium is considered more desirable than the digital counterpart, due to the amount of non-proportional pixel-decimated scaling that is applied to the width of an image to achieve (something of a misnomer) a so-called "rectangular" pixel widescreen image. The legacy
Film
Many commercial films (especially epics – usually with the CinemaScope 2.35:1 optical sound or the older 4-track mag sound 2.55:1 aspect ratio) are recorded on standard 35 mm ~4:3 aspect ratio film,[a] using an anamorphic lens to horizontally compress all footage into a ~4:3 frame. Another anamorphic lens on the movie theatre projector corrects (optically decompresses) the picture (see anamorphic format for details). Other movies (often with aspect ratios of 1.85:1 in the USA or 1.66:1 in Europe) are made using the simpler matte technique, which involves both filming and projecting without any expensive special lenses. The movie is produced in 1.375 format, and then the resulting image is simply cropped in post-production (or perhaps in the theater's projector) to fit the desired aspect ratio of 1.85:1 or 1.66:1 or whatever is desired. Besides costing less, the main advantage of the matte technique is that it leaves the studio with "real" footage (the areas that are cropped for the theatrical release) which can be used in preference to pan and scan when producing 4:3 DVD releases, for example.
The anamorphic encoding on DVD is related to the anamorphic filming technique (like CinemaScope) only by name. For instance, Star Wars (1977) was filmed in 2.39:1 ratio using an anamorphic camera lens, and shown in theaters using the corresponding projector lens. Since it is a widescreen film, when encoded on a widescreen-format DVD the studio would almost certainly use the anamorphic encoding process. Monty Python and the Holy Grail was filmed in 1.85:1 ratio without using an anamorphic lens on the camera, and similarly was shown in theaters without the need for the decompression lens. However, since it is also a widescreen film, when encoded on a widescreen-format DVD the studio would probably use the anamorphic encoding process.
It does not matter whether the filming was done using the anamorphic lens technique: as long as the source footage is intended to be widescreen, the digital anamorphic encoding procedure is appropriate for the DVD release. As a sidenote, if a purely non-widescreen version of the analog-anamorphic Star Wars were to be released on DVD, the only options would be pan and scan or hardcoded 4:3 letterboxing (with the black letterboxes actually encoded as part of the DVD data).
Laserdisc
While not anamorphic widescreen per se, many of the earliest Laserdisc offerings forwent the pan-and-scan cropping typical of home releases at the time, the mastering-technicians opting instead to simply squeeze the film's original aspect ratio down to 4:3. While this resulted in an image that was overly compressed on standard televisions, many later HDTVs can stretch out this picture, thus restoring the correct aspect ratio.
Later during the 1990s, a handful of Laserdiscs were released with proper anamorphic transfers. Video was stretched vertically to fill the whole 4:3 picture of a Laserdisc (and add more information where black bars would be at the top and bottom) then either un-squeezed horizontally on a 16:9 TV set or using an anamorphic lens on a 4:3 video projector.
DVD Video
A DVD labeled as "Anamorphic Widescreen" contains video that has the same frame size in pixels as traditional fullscreen video, but uses wider pixels. The shape of the pixels is called pixel aspect ratio and is encoded in the video stream for a DVD player to correctly identify the proportions of the video. If an anamorphic DVD video is played on standard 4:3 television without adjustment, the image will look horizontally squeezed. The menus are also anamorphic.
Packaging
Although currently there is no labeling standard, DVDs with content originally produced in an aspect ratio wider than 1.33:1 are typically labeled "Anamorphic Widescreen", "Enhanced for 16:9 televisions", "Enhanced for widescreen televisions", or similar. If not so labeled, the DVD is intended for a 4:3 display ("fullscreen"), and will be
There has been no clear standardization for companies to follow regarding the advertisement of anamorphically enhanced widescreen DVDs. Some companies, such as Universal and Disney, include the aspect ratio of the movie.
Blu-ray video
Unlike DVD,
Blu-ray also supports anamorphic wide-screen, both at the DVD-Video/
Television
Major
Many modern
ATSC allows two anamorphic widescreen SDTV formats (
See also
Notes
- ^ The standard 1932 Academy ratio changed the true aspect ratio of the image data to 1.375 when they made space for audio tracks, however, this is close enough to 4:3 that the difference is often glossed over.
References
- ^ "Full height anamorphic". Oxford Reference. Retrieved April 22, 2018.