Letterboxing 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 videographic image has mattes (black bars) above and below it; these mattes are part of the image (i.e., of each frame of the video signal). LTBX is the identifying abbreviation for films and images so formatted. The term refers to the shape of a letter box, a slot in a wall or door through which mail is delivered, being rectangular and wider than it is high.
Letterboxing is used as an alternative to a full-screen, pan-and-scan transfer of a widescreen film, in which the original image is cropped to the narrower aspect ratio of the destination format, usually the 1.33:1 (4:3) ratio of the standard television screen, whereas letterboxing preserves the film’s original image composition as seen in the cinema. Letterboxing was developed for use in 4:3 television displays before widescreen television screens were available, but it is also necessary to represent on a 16:9 widescreen display the unaltered original composition of a film with a wider aspect ratio, such as Panavision’s 2.35:1 ratio.
Letterbox mattes are usually symmetrical, but in some instances the picture can be elevated so the bottom matte is much larger, usually for the purpose of placing ‘hard’ subtitles within the matte to avoid overlapping of the image. This was often done for letterbox widescreen anime on VHS, though the practice of ‘hiding’ subtitles within the lower matte also is done with symmetrical mattes, albeit with less space available. The placing of ‘soft’ subtitles within the picture or matte varies according to the DVD player being used, though it appears to be dependent on the movie for Blu-ray disc.
An alternative to letterboxing is anamorphic widescreen presentation, which squeezes the picture horizontally to fit into a narrower aspect ratio. The player or receiver must correct this distortion by either stretching the image back to its original relative width, for display on widescreen televisions, or letterboxing it (during playback) for display on 4:3 video screens. This image transformation generally requires digital signal processing, so letterboxing was the only way in which films were presented in widescreen on home video prior to the DVD format (with a few exceptions outside the mass market, such as Squeeze LD for Laserdisc). Anamorphic widescreen video recordings are sometimes called ‘anamorphically enhanced,’ in comparison to letterboxed versions. To represent a film wider than 16:9 (e.g., a 2.35:1 film) on a 16:9 display with no cropping, both anamorphic and letterbox techniques (or letterboxing alone) are required; using the anamorphic technique, the mattes will be smaller but still necessary.
Academy ratio (1.37:1) film or video is sometimes stretched to fill a widescreen (16:9) television display, resulting in distortion in which actors appear shorter and fatter. This horizontal stretching distortion can be avoided by pillar boxing the image, effected either in the television set or in the video player, e.g. a DVD player. Occasionally, video is shot in a widescreen format and encoded into 4:3 video incorporating letterboxing into the 4:3 image. This effect is common on personal video websites and old documentaries. A letterboxed recording will appear letterboxed on every screen – even one that has the same aspect ratio as the source content.
The first use of letterbox appeared with the RCA videodisc (CED) format. Initially, letterboxing was limited to several key sequences of a film (e.g., opening and closing credits), but later it was used for the entire film. The first full letterboxed CED release was ‘Amarcord’ in 1984, and several others followed. Each disc contained a label noting the use of ‘RCA’s innovative wide-screen mastering technique.’
In NTSC areas of the world, videocassettes often contained only pan-and-scan versions (notable VHS releases in letterboxed format include ‘Manhattan,’ ‘Last Tango in Paris,’ ‘Ghostbusters II’ (which was released in the incorrect aspect ratio on its initial home video release), ‘The Terminator,’ ‘The Color Purple,’ ‘Lady and the Tramp,’ and ‘Basic Instinct: The Original Director’s Cut),’ but DVD releases tend to be offered in both versions. In PAL areas, which do not suffer so much from low vertical resolution with letterboxed images, letterboxing was more common on videocassettes and is almost ubiquitous on DVDs, with very few films being offered in pan-and-scan releases today.
Movies such as ‘The Graduate’ and ‘Woodstock’ that made use of the full width of the movie screen often have the sides cut off and look completely different in non-letterboxed copies from the original theatrical release. This is more apparent in pan-and-scanned movies that remain entirely on the center area of the film image.
The term ‘SmileBox’ is a registered trademark used to describe a type of letterboxing for Cinerama films (a widescreen process which works by simultaneously projecting images from three synchronized 35 mm projectors onto a huge, deeply-curved screen), such as on the Blu-ray release of ‘How the West Was Won.’ The image is produced with 3D mapping technology to approximate a curved screen.
Digital broadcasting allows 1.78:1 (16:9) widescreen format transmissions without losing resolution, and thus widescreen is becoming the television norm. Most television programming in the United States, Britain, and France is in standard-definition 16:9 and is transmitted in anamorphic format on digital platforms. When using a 4:3 television, it is possible to display such programming in either a letterbox format or in a 4:3 center-cut format (where the edges of the picture are lost). A letterboxed 14:9 compromise ratio is often broadcast in analogue transmissions in European countries making the transition from 4:3 to 16:9. In addition, recent years have seen an increase of ‘fake’ 2.35:1 letterbox mattes on television to give the impression of a cinema film, often seen in adverts, trailers or shows such as ‘Top Gear.’
Letterbox mattes are not necessarily black. IBM has used blue mattes for many of their TV ads, yellow mattes in their ‘I am Superman’ Lotus ads, and green mattes in ads about efficiency & environmental sustainability. Others uses of colored mattes appear in ads from Allstate, Aleve, and Kodak among others, and in music videos such as Zebrahead’s ‘Playmate of the Year.’ In other instances mattes are animated, such as in the music video for ‘Never Gonna Stop (The Red Red Kroovy),’ and even parodied such as the final scene of the ‘Crazy Frog Axel F’ music video in which Crazy Frog peeks over the matte on the lower edge of the screen with part of his hands overlapping the matte. Similar to breaking the border of a comic’s panel, it is a form of breaking the fourth wall.
Pillarboxing (reversed letterboxing) is the display of an image within a wider image frame by adding lateral mattes (vertical bars at the sides); for example, a 1.33:1 image has lateral mattes when displayed on a 16:9 aspect ratio television screen. An alternative to pillarboxing is ’tilt-and-scan’ (reversed pan and scan), horizontally matting the original 1.33:1 television images to the 1.78:1 aspect ratio, which at any given moment crops part of the top and/or bottom of the frame, hence the need for the ’tilt’ component. A tilt is a camera move in which the camera tilts up or down. Windowboxing occurs when an image appears centered in a television screen, with blank space on all four sides of the image, such as when a widescreen image that has been previously letterboxed to fit 1.33:1 is then pillarboxed to fit 16:9. It is also called ‘matchbox,’ ‘gutterbox,’ and ‘postage stamp display.’
It is common to see windowboxed commercials on HD television networks, because many commercials are shot in 16:9 but distributed to networks in SD, letterboxed to fit 1.33:1. Many 1980s 8-bit home computers feature gutterboxing display mode, because the TV screens normally used as monitors at that time tended to distort the image near the border of the screen. Moreover, due to the overscanned nature of television video, the precise edges of the visible area of the screen varied from television set to television set, so characters near the expected border of the active screen area might be behind the bezel or off the edge of the screen. Occasionally, an image is deliberately windowboxed for stylistic effect; for example, the documentary-style sequence of the film ‘Rent’ suggest an older-format camera representing the 4:3 aspect ratio, and the opening sequence of the Oliver Stone film ‘JFK’ features pillar boxing to represent the 1960s era 4:3 television footage. The film ‘Sneakers’ uses a windowboxing effect in a scene for dramatic effect.