Anamorphic widescreen

Last updated December 17, 2024

Anamorphic widescreen (also called full-height anamorphic or FHA) is a process by which a widescreen image is horizontally compressed to fit into a storage medium (photographic film or MPEG-2 standard-definition frame, for example) with a narrower aspect ratio, reducing the horizontal resolution of the image while keeping its full original vertical resolution. Compatible play-back equipment (a projector with modified lens, or a digital video player or set-top box) can then expand the horizontal dimension to show the original widescreen image. This is typically used to allow one to store widescreen images on a medium that was originally intended for a narrower ratio, while using as much of the frame – and therefore recording as much detail – as possible.^[1]

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 concave lens to fit into non-widescreen 1.37:1 aspect ratio film. This film can then be printed and manipulated like any other 1.37:1 film stock, although the images on it will appear to be squashed horizontally (or elongated vertically). An anamorphic lens on the projector in the cinema (a convex lens) corrects the picture by performing the opposite distortion, returning it to its original width and its widescreen aspect ratio.

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 ITU-R Rec. 601 4:3 image size is used for its compatibility with the original video bandwidth that was available for professional video devices that used fixed clock rates of a SMPTE 259M serial digital interface. One would produce a higher-quality upscaled 16:9 widescreen image by using either a 1:1 SD progressive frame size of 640×360 or for ITU-R Rec. 601 and SMPTE 259M compatibility a letterboxed frame size of 480i or 576i. Similar operations are performed electronically to allow widescreen material to be stored on formats or broadcast on systems that assume a non-widescreen aspect ratio, such as DVD or standard definition digital television broadcasting.

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 letterboxed or panned and scanned.

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 supports SMPTE HD resolutions of 720p and 1080i/p with a display aspect ratio of 16:9 and a pixel aspect ratio of 1:1, so widescreen video is scaled non-anamorphically (this is referred to as "square" pixels).

Blu-ray also supports anamorphic widescreen, both at the DVD-Video/D-1 resolutions of 720×480 (NTSC) and 720×576 (PAL), and at the higher resolution of 1440×1080 (source aspect ratio of 4:3, hence a pixel aspect ratio of 4:3 = 16:9 / 4:3 when used as anamorphic 16:9). See Blu-ray Disc: Technical specifications for details.

Television

Major digital television channels in Europe (for example, the five major UK terrestrial TV channels of BBC One, BBC Two, ITV, Channel 4 and Channel 5), as well as Australia, carry anamorphic widescreen programming in standard definition. In almost all cases, 4:3 programming is also transmitted on the same channel. The SCART switching signal can be used by a set-top-box to signal the television which kind of programming (4:3 or anamorphic) is currently being received, so that the television can change modes appropriately. The user can often elect to display widescreen programming in a 4:3 letterbox format instead of pan and scan ^{[ citation needed ]} if they do not have a widescreen television.

TV stations and TV networks can also include Active Format Description (AFD) just as DVDs can. Many ATSC tuners (integrated or set-top box) can be set to respond to this, or to apply a user setting. This can sometimes be set on a per-channel basis, and often on a per-input basis, and usually easily with a button on the remote control. However, tuners often fail to allow this on SDTV (480i-mode) channels, so that viewers are forced to view a small picture instead of cropping the unnecessary sides (which are outside of the safe area), or zooming to eliminate the windowboxing that may be causing a small picture, or stretching/compressing to eliminate other format-conversion errors. The shrunken pictures are especially troublesome for smaller TV sets.

Many modern HDTV sets have the capability to detect black areas in any video signal, and to smoothly re-scale the picture independently in both directions (horizontal and vertical) so that it fills the screen. However, some sets are 16:10 (1.6:1) like some computer monitors, and will not crop the left and right edges of the picture, meaning that all programming looks slightly (though usually imperceptibly) tall and thin.

ATSC allows two anamorphic widescreen SDTV formats (interlaced and progressive scan) which are 704×480 (10% wider than 640×480); this is narrower than the 720×480 of DVD due to 16 pixels being consumed by overscan (nominal analogue blanking) – see overscan: analog to digital resolution issues. The format can also be used for fullscreen programming, and in this case it is anamorphic with pixels slightly taller (10:11, or 0.91:1) than their width.

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.

Related Research Articles

Letter-boxing is the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio. The resulting video-graphic image has mattes of empty space above and below it; these mattes are part of each frame of the video signal.

Pan and scan is a method of adjusting widescreen film images so that they can be shown in fullscreen proportions of a standard-definition 4:3 (1.33:1) aspect ratio television screen, often cropping off the sides of the original widescreen image to focus on the composition's most important aspects.

<span class="mw-page-title-main">Standard-definition television</span> Digital TV with similar definition to analog broadcasts

Standard-definition television is a television system that uses a resolution that is not considered to be either high or enhanced definition. Standard refers to offering a similar resolution to the analog broadcast systems used when it was introduced.

Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) systems, which, in turn, were replaced by flat-panel displays of several types.

Widescreen images are displayed within a set of aspect ratios used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than 4:3 (1.33:1).

35 mm film is a film gauge used in filmmaking, and the film standard. In motion pictures that record on film, 35 mm is the most commonly used gauge. The name of the gauge is not a direct measurement, and refers to the nominal width of the 35 mm format photographic film, which consists of strips 1.377 ± 0.001 inches (34.976 ± 0.025 mm) wide. The standard image exposure length on 35 mm for movies is four perforations per frame along both edges, which results in 16 frames per foot of film.

70 mm film is a wide high-resolution film gauge for motion picture photography, with a negative area nearly 3.5 times as large as the standard 35 mm motion picture film format. As used in cameras, the film is 65 mm (2.6 in) wide. For projection, the original 65 mm film is printed on 70 mm (2.8 in) film. The additional 5 mm contains the four magnetic stripes, holding six tracks of stereophonic sound. Although later 70 mm prints use digital sound encoding, the vast majority of existing and surviving 70 mm prints pre-date this technology.

The display resolution or display modes of a digital television, computer monitor, or other display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode-ray tube (CRT) displays, flat-panel displays and projection displays using fixed picture-element (pixel) arrays.

Negative pulldown is the manner in which an image is exposed on a film stock, described by the number of film perforations spanned by an individual frame. It can also describe whether the image captured on the negative is oriented horizontally or vertically. Changing the number of exposed perforations allows a cinematographer to change both the aspect ratio of the image and the size of the area on the film stock that the image occupies.

High-definition video is video of higher resolution and quality than standard-definition. While there is no standardized meaning for high-definition, generally any video image with considerably more than 480 vertical scan lines or 576 vertical lines (Europe) is considered high-definition. 480 scan lines is generally the minimum even though the majority of systems greatly exceed that. Images of standard resolution captured at rates faster than normal, by a high-speed camera may be considered high-definition in some contexts. Some television series shot on high-definition video are made to look as if they have been shot on film, a technique which is often known as filmizing.

Cropping is the removal of unwanted outer areas from a photographic or illustrated image. The process usually consists of the removal of some of the peripheral areas of an image to remove extraneous visual data from the picture, improve its framing, change the aspect ratio, or accentuate or isolate the subject matter from its background. Depending on the application, this can be performed on a physical photograph, artwork, or film footage, or it can be achieved digitally by using image editing software. The process of cropping is common to the photographic, film processing, broadcasting, graphic design, and printing businesses.

Open matte is a filming technique that involves matting out the top and bottom of the film frame in the movie projector for the widescreen theatrical release and then scanning the film without a matte for a full screen home video release. It is roughly equivalent to an uncropped version of the film.

Univisium is a proposed universal film format created by cinematographer Vittorio Storaro, ASC, AIC and his son, Fabrizio, to unify all future theatrical and television films into one respective aspect ratio of 2:1.

The pillarbox effect occurs in widescreen video displays when black bars are placed on the sides of the image. It becomes necessary when film or video that was not originally designed for widescreen is shown on a widescreen display, or a narrower widescreen image is displayed within a wider aspect ratio, such as a 16:9 image in a 2.39:1 frame. The original material is shrunk and placed in the middle of the widescreen frame.

<span class="mw-page-title-main">Windowbox (filmmaking)</span> The often undesirable combination of letterboxing and pillarboxing

Windowboxing in the display of film or video occurs when the aspect ratio of the media is such that the letterbox effect and pillarbox effect occur simultaneously. Sometimes, by accident or design, a standard ratio image is presented in the central portion of a letterbox picture, resulting in a black border all around. It is generally disliked because it wastes much screen space and reduces the resolution of the original image. It can occur when a 16:9 film is set to 4:3 (letterbox), but then shown on a 16:9 TV or other output device. It can also occur in the opposite direction. Few films have been released with this aspect ratio — one example is The Crocodile Hunter: Collision Course, which had numerous scenes with Steve & Terri Irwin using widescreen pillar boxing.

Anamorphic format is the cinematography technique of shooting a widescreen picture on standard 35 mm film or other visual recording media with a non-widescreen native aspect ratio. It also refers to the projection format in which a distorted image is "stretched" by an anamorphic projection lens to recreate the original aspect ratio on the viewing screen.

The technology of television has evolved since its early days using a mechanical system invented by Paul Gottlieb Nipkow in 1884. Every television system works on the scanning principle first implemented in the rotating disk scanner of Nipkow. This turns a two-dimensional image into a time series of signals that represent the brightness and color of each resolvable element of the picture. By repeating a two-dimensional image quickly enough, the impression of motion can be transmitted as well. For the receiving apparatus to reconstruct the image, synchronization information is included in the signal to allow proper placement of each line within the image and to identify when a complete image has been transmitted and a new image is to follow.

"21:9" is a consumer electronics (CE) marketing term to describe the ultrawide aspect ratio of 64:27, designed to show films recorded in CinemaScope and equivalent modern anamorphic formats. The main benefit of this screen aspect ratio is a constant display height when displaying other content with a lesser aspect ratio.

The aspect ratio of an image is the ratio of its width to its height. It is expressed as two numbers separated by a colon, in the format width:height. Common aspect ratios are 1.85:1 and 2.40:1 in cinematography, 4:3 and 16:9 in television, and 3:2 in still photography.

Ultrawide formats refers to photos, videos, and displays with aspect ratios greater than 2. There were multiple moves in history towards wider formats, including one by Disney, with some of them being more successful than others.

References

↑ "Full height anamorphic". Oxford Reference. Retrieved April 22, 2018.

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[2] 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.

[1] "Full height anamorphic". Oxford Reference. Retrieved April 22, 2018.

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