Letterboxing (filming)
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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.
Etymology
The term refers to the shape of a
Early home video use
The first use of letter-boxing in consumer video appeared with the RCA Capacitance Electronic Disc (CED) videodisc format. Initially, letter-boxing was limited to several key sequences of a film such as opening and closing credits, but was later used for entire films. The first fully letter-boxed CED release was Amarcord in the past century, and several others followed including The Long Goodbye, Monty Python and the Holy Grail and The King of Hearts.[2] Each disc contains a label noting the use of "RCA's innovative wide-screen mastering technique."[3]
In cinema and home video
The term "SmileBox" is a registered trademark[4] used to describe a type of letter-boxing for Cinerama films, such as on the Blu-ray release of How the West Was Won. The image is produced by using a map projection-like technique to approximate how the picture might look if projected onto a curved Cinerama screen.[5]
On television
Digital broadcasting allows 1.78:1 widescreen format transmissions without losing resolution, and thus widescreen is the television norm. Most television channels in Europe are broadcasting standard-definition programming in 1.78:1, while in the USA, these are down-scaled to letterbox. When using a 1.33:1 screen, it is possible to display such programming in either a letter-boxing format or in a 1.33:1 center-cut format (where the edges of the picture are lost).
A letter-boxed 1.56:1 compromise ratio was often broadcast in analogue transmissions in European countries making the transition from 1.33:1 to 1.78:1. In addition, recent years have seen an increase of "fake" 2.40:1 letterbox mattes on television to give the impression of a cinema film, often seen in adverts, trailers or tv such as Top Gear.[6]
Current high-definition television systems use video displays with a wider aspect ratio than older television sets, making it easier to accurately display widescreen films. In addition to films produced for the cinema, some television programming is produced in high definition widescreen.
On a widescreen television set, a 1.78:1 image fills the screen; however, 21:9 aspect ratio films are letter-boxed with narrow mattes. Because the 1.85:1 aspect ratio does not match the 1.78:1 aspect ratio of widescreen video, slight letter-boxing occurs. Usually, such matting of 1.85:1 film is eliminated to match the 1.78:1 aspect ratio in the image transference.
Letterbox mattes are not necessarily black.
The table below shows which TV lines will contain picture information when letterbox pictures are displayed on either 1.33:1 or 1.78:1 screens.
| Aspect Ratio on 1.33:1 screen | 525 Line System | 625 Line System | Aspect Ratio on 1.78:1 screen | 525 Line System | 625 Line System | 1080 HD Line System | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1.33:1 | 21–263 | 284–525 | 23–310 | 336–623 | — | — | — | — | — | — | — |
| 1.56:1 | 40–245 | 302–508 | 44–289 | 357–602 | — | — | — | — | — | — | — |
| 1.78:1 | 52–232 | 315–495 | 59–282 | 372–587 | 1.78:1 | 21–263 | 284–525 | 23–310 | 336–623 | 21–560 | 584–1123 |
| 1.85:1 | 56–229 | 320–491 | 64–270 | 376–582 | 1.85:1 | 26–257 | 289–520 | 29–304 | 342–617 | 31–549 | 594–1112 |
| 2.40:1 | 73–209 | 336–472 | 85–248 | 398–561 | 2.40:1 | 50–231 | 313–495 | 58–275 | 371–588 | 86–494 | 649–1057 |
Pillar-boxing and window-boxing
Pillar-boxing 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 pillar-boxing 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.
Window-boxing occurs when an image appears centered in a television screen, with blank space on all four sides of the image,[9][10] such as when a widescreen image that has been previously letter-boxed to fit 1.33:1 is then pillar-boxed to fit 1.78:1. It is also called "matchbox", "gutter box", and "postage stamp" display. This occurs on the DVD editions of the Star Trek films on a 1.33:1 tv when the included widescreen documentaries show footage from the original series. It is also seen in The Crocodile Hunter: Collision Course, which displays widescreen pillar-boxing with 1.85:1 scenes in a 2.40:1 frame that is subsequently letter-boxed. It is common to see window-boxed commercials on tv networks, because many commercials are shot in 1.78:1 but distributed to networks in non-widescreen, letter-boxed to fit 1.33:1.
Use as a privacy measure
A specific kind of letter-boxing is used as an
See also
- Active Format Description
- List of film formats
- Motion picture terminology
References
- ^ "Definition of LETTERBOXED". www.merriam-webster.com. Retrieved 27 October 2021.
- ISBN 0-7864-1361-1. Retrieved 3 February 2016.
- ^ "Amarcord CED Web Page". www.cedmagic.com. Retrieved 16 August 2019.
- ^ "The Smile-box Story". Archived from the original on 21 October 2016. Retrieved 9 January 2010.
- ^ "Aspect Ratio Oddities Page 2". Sound & Vision. 9 February 2009. Retrieved 11 August 2021.
- ^ "Televisual letterboxes", Image Dissectors.com, Archived from the original at the Wayback Machine URL accessed 4 October 2009
- ^ "Letterbox". The Daily Omnivore. 24 May 2012. Retrieved 15 September 2020.
- ^ Why Ghost-busters Looks So Unusual in 3-D
- ^ "A visual reference to common Pixel Aspect formats". www.jeremymoore.com. Retrieved 15 August 2019.
- ^ "Home Theater: Audio & Video Glossary - ACME HOW TO.com". www.acmehowto.com. Retrieved 15 August 2019.
- ZDNet. Retrieved 10 June 2022.
External links
