Aspect ratio (image)

This article is about aspect ratio of still images, films, and digital imagery. For display aspect ratio, seedisplay aspect ratio.

Theaspect ratioof an image is the ratio of its width to its height. It is expressed as two numbers separated by a colon,width:height.Common aspect ratios are 1.85:1 and 2.40:1 incinematography,4:3and16:9intelevision,and 3:2 instill photography.

Some common examples

Common aspect ratios used in film and displays images

The common film aspect ratios used in cinemas are 1.85:1 and 2.40:1.Two commonvideographicaspect ratios are 4:3 (1.3:1),the universal video format of the 20th century, and16:9(1.7:1), universal forhigh-definition televisionand Europeandigital television.Other cinematic and video aspect ratios exist, but are used infrequently.

Instill cameraphotography, the most common aspect ratios are 4:3, 3:2 (1.5:1), and more recently found in consumer cameras, 16:9.Other aspect ratios, such as 5:3, 5:4, and 1:1 (square format), are used in photography as well, particularly inmedium formatandlarge format.

With television,DVDandBlu-ray Disc,converting formats of unequal ratios is achieved by enlarging the original image to fill the receiving format's display area and cutting off any excess picture information (zoomingandcropping), by adding horizontal mattes (letterboxing) or vertical mattes (pillarboxing) to retain the original format's aspect ratio, by stretching (hence distorting) the image to fill the receiving format's ratio, or by scaling by different factors in both directions, possibly scaling by a different factor in the center and at the edges (as inWide Zoom mode).

Practical limitations

In motion picture formats, the physical size of the film area between thesprocketperforations determines the image's size. The universal standard (established byWilliam DicksonandThomas Edisonin 1892) is a frame that is four perforations high. The film itself is 35 mm wide (1.38 in), but the area between the perforations is 24.89 mm × 18.67 mm (0.980 in × 0.735 in), leaving the de facto ratio of 1.33:1.

With a space designated for the standardoptical soundtrack,and the frame size reduced to maintain an image that is wider than tall; this resulted in theAcademyaperture of 22 mm × 16 mm (0.866 in × 0.630 in) or 1.375:1 aspect ratio.

Cinema terminology

Themotion picture industryconvention assigns a value of 1 to the image's height; ananamorphicframe (since 1970, approximately 2.39:1) is often incorrectly described (rounded) as either 2.4:1 or 2.40:1. After 1952, a number of aspect ratios were experimented with for anamorphic productions, including 2.66:1 and 2.55:1.ASMPTEspecification for anamorphic projection from 1957 (PH22.106-1957) finally standardized the aperture to 2.35:1.An update in 1970 (PH22.106-1971) changed the aspect ratio to 2.40:1 in order to make splices less noticeable.This aspect ratio of 2.40:1 was confirmed by the most recent revision from August 1993 (SMPTE 195-1993).

In American cinemas, the common projection ratios are 1.85:1 and 2.40:1. Some European countries have 1.6:1 as the wide screen standard. The "Academy ratio" of 1.375:1 was used for all cinema films in the sound era until 1953 (with the release ofGeorge Stevens'Shanein 1.6:1). During that time, television, which had a similar aspect ratio of 1.3:1, became a perceived threat to movie studios. Hollywood responded by creating a large number of wide-screen formats:CinemaScope(up to 2.6:1),Todd-AO(2.20:1), andVistaVision(up to 2.00:1) to name just a few. The flat 1.85:1 aspect ratio was introduced in May 1953, and became one of the most common cinema projection standards in the United States and elsewhere.

The goal of these various lenses and aspect ratios was to capture as much of the frame as possible, onto as large an area of the film as possible, in order to fully utilize the film being used. Some of the aspect ratios were chosen to utilize smaller film sizes in order to save film costs while other aspect ratios were chosen to use larger film sizes in order to produce a wider higher resolution image. In either case the image was squeezed horizontally to fit the film's frame size and avoid any unused film area.

Movie camera systems

The development of various film camera systems must ultimately cater to the placement of the frame in relation to the lateral constraints of the perforations and the optical soundtrack area. One clever wide screen alternative,VistaVision,used standard 35 mm film running sideways through the camera gate, so that the sprocket holes were above and below frame, allowing a larger horizontal negative size per frame as only the vertical size was now restricted by the perforations. There were even a limited number of projectors constructed to also run the print-film horizontally. Generally, however, the 1.50:1 ratio of the initial VistaVision image was optically converted to a vertical print (on standard four-perforation35 mm movie film) to show with the standard projectors available at theaters, and was then masked in the projector to the United States standard of 1.85:1. The format was briefly revived byLucasfilmin the late 1970s for special effects work that required a larger negative size (due to image degradation from the optical printing steps necessary to make multi-layer composites). It went into obsolescence largely due to better cameras, lenses, and film stocks available for standard four-perforation formats, in addition to increased lab costs for making prints in comparison to more standard vertical processes. (The horizontal process was also adapted to 70 mm film byIMAX,which was first shown at the Osaka '70 Worlds Fair.)

Super 16 mm filmwas frequently used for television production due to its lower cost, lack of need for soundtrack space on the film itself (as it is not projected but rather transferred to video), and aspect ratio similar to 16:9 (the native ratio of Super 16 mm is 15:9). It also can be blown up to 35 mm for theatrical release and therefore is sometimes used for feature films.

Current video standards

1:1

Square displays are rarely used in devicesand monitors.Nonetheless, video consumption on social apps has grown rapidly and led to the emergence of new video formats more suited to mobile devices that can be held in horizontal and vertical orientations. In that sense, square video was popularized by mobile apps such asInstagramandVineand has since been supported by other major social platforms includingFacebookandX.It can fill nearly twice as much screen space compared to 16:9 format (when the device is held differently while viewing from how video was recorded).

4:3

Main article:Fullscreen (aspect ratio)

4:3 (1.33:1) (generally read as Four-Three, Four-by-Three, or Four-to-Three) for standard television for fullscreen aspect ratio 1.33:1 has been in use since the invention ofmoving picture cameras,and manycomputer monitorsused to employ the same aspect ratio. 4:3 was the aspect ratio used for35 mm filmsin thesilent era.It is also very close to the 1.375:1Academy ratio,defined by theAcademy of Motion Picture Arts and Sciencesas a standard after the advent of opticalsound-on-film.By having TV match this aspect ratio, movies originally photographed on 35 mm film could be satisfactorily viewed on TV in the early days of the medium (i.e. the 1940s and the 1950s).

With the adoption ofhigh-definition television,the majority of modern televisions are now produced with 16:9 displays instead. Apple'siPadseries oftabletscontinue to use 4:3 displays (despite other Apple products typically using widescreen aspect ratios) to better suit use as ane-reader;however, the 2018 iPad Pro 11-inch uses a 1.43:1 aspect ratio.

14:9

Main article:14:9 aspect ratio

14:9 (generally named as Fourteen-by-Nine, Fourteen-Nine, and Fourteen-to-Nine) is the aspect ratio mainly used when the 4:3 programs are cropped.

16:10

Main article:16:10 aspect ratio

16:10(8:5) is anaspect ratiomostly used forcomputer displaysandtablet computers.The width of the display is 1.6 times its height. This ratio is close to thegolden ratio"$\varphi$"which is approximately 1.618. LCD computer displays using the 16:10 ratio started to appear in the mass market from 2003. By 2008, 16:10 had become the most common aspect ratio forLCD monitorsandlaptopdisplays.Since 2010, however, 16:9 has become the mainstream standard, driven by the 1080p standard for high definition television and lower manufacturing costs.

In 2005–2008, 16:10 (1.6:1) overtook 4:3 as the most sold aspect ratio for LCD monitors. At the time, 16:10 also had 90% of the notebook market and was the most commonly used aspect ratio for laptops.However, 16:10 had a short reign as the most common aspect ratio. Around 2008–2010, there was a rapid shift by computer display manufacturers to the 16:9 aspect ratio and by 2011 16:10 had almost disappeared from new mass market products. According toNet Applications,by October 2012 the market share of 16:10 displays had dropped to less than 23 percent.

Notably, Apple used 16:10 for all of itsMacBookmodels until 2021, when the5th-generation MacBook Proswitched to a taller aspect ratio of approximately 1.54:1.TheMacBook Aircontinues to use 16:10 as of 2022.

16:9

Main article:16:9 aspect ratio

16:9(1.77:1) (generally named as Sixteen-by-Nine, Sixteen-Nine, and Sixteen-to-Nine) is the international standard format ofHDTV,non-HD digitaltelevisionand analog widescreen televisionPALplus.Japan'sHi-Visionoriginally started with a 5:3 (= 15:9) ratio but converted when the international standards group introduced a wider ratio of5+1⁄3to 3 (= 16:9). Manydigital videocameras have the capability to record in 16:9 (= 4²:3²), and 16:9 is the only widescreen aspect ratio natively supported by theDVDstandard. DVD producers can also choose to show even wider ratios such as 1.66:1, 1.75:1, 1.77:1 and 1.78:1within the 16:9 DVD frame byhard mattingor adding black bars within the image itself. The 16:9 aspect ratio was used often in British TVs in the United Kingdom in the 1990s, and is also used in how smartphones, laptops, and desktops.

1.85:1

Equivalent to integer ratio of 37:20. Whencinemaattendance dropped, Hollywood createdwidescreenaspect ratios in order to differentiate the film industry from TV, with one of the most common being the 1.85:1 ratio.

2.00:1

Main article:Univisium

The 2.00:1 aspect ratio was first used in the 1950s for the RKO Superscope format.

Since 1998, cinematographerVittorio Storarohas advocated for a format named "Univisium"that uses a 2.00:1 format.Univisium has gained little traction in the theatrical film market, but has recently been used byNetflixandAmazon Videofor productions such asHouse of CardsandTransparent,respectively. This aspect ratio is similar to the 1.90:1 standard acquisition formats mandated by these content platforms and is not necessarily a creative choice.

Moreover, some mobile devices, such as theLG G6,LG V30,Huawei Mate 10 Pro,Google Pixel 2 XL,OnePlus 5TandSony Xperia XZ3,are embracing the 2.00:1 format (advertised as 18:9), as well as theSamsung Galaxy S8,Samsung Galaxy Note 8,Samsung Galaxy S9andSamsung Galaxy Note 9with a slightly similar 18.5:9 format.The AppleiPhone Xalso has a similar screen ratio of 19.5:9 (2.16:1).

2.40:1

Main articles:Anamorphic formatandAnamorphic widescreen

Anamorphic format is thecinematographytechnique of shooting awidescreenpicture on standard35 mm filmor other visual recording media with a non-widescreen native aspect ratio. When projected the image is then stretched back into the original proportions.

Obtaining height, width, and area of the screen

Often, screen specifications are given by their diagonal length. The following formulae can be used to find the height (h), width (w) and area (A), whererstands for ratio, written as a fraction ofxbyy,anddfor diagonal length.

$r={\frac {x}{y}}$

$h={\frac {d}{\sqrt {r^{2}+1}}}={\frac {y\times d}{\sqrt {x^{2}+y^{2}}}}$

$w={\frac {r\times d}{\sqrt {{r^{2}}+1}}}={\frac {x\times d}{\sqrt {x^{2}+y^{2}}}}$

$A={\frac {r\times d^{2}}{{r^{2}}+1}}\quad ={\frac {x\times y\times d^{2}}{x^{2}+y^{2}}}$

Distinctions

This article primarily addresses the aspect ratio of imagesas displayed,which is more formally referred to as thedisplay aspect ratio(DAR).Indigital images,there is a distinction with thestorage aspect ratio(SAR),which is the ratio ofnumbers of pixels.If an image is displayed withsquare pixels,then these ratios agree. If, instead, non-square ( "rectangular" ) pixels are used, then these ratios differ. The aspect ratio of the pixels themselves is known as thepixel aspect ratio(PAR)– for square pixels this is 1:1 – and these are related by the identity:

SAR × PAR = DAR

Rearranging (solving for PAR) yields:

PAR = DAR/SAR

For example:

• A 640 × 480VGAimage has
  • a SAR of 640/480 = 4:3
  • and if displayed on a 4:3 display (DAR = 4:3), has square pixels, hence a PAR of 1:1.
• By contrast, a 720 × 576D-1PAL image has
  • a SAR of 720/576 = 5:4
  • but is displayed on a 4:3 display (DAR = 4:3), so by this formula it would have a PAR of (4:3)/(5:4) = 16:15.

However, because standard definition digital video was originally based on digitally sampling analog television, the 720 horizontal pixels actually capture a slightly wider image to avoid loss of the original analog picture. In actual images, these extra pixels are often partly or entirely black, as only the center 704 horizontal pixels carry actual 4:3 or 16:9 image. Hence, the actual pixel aspect ratio PAR for PAL video is a little different from that given by the formula, specifically 12:11 for PAL and 10:11 for NTSC. For consistency, the same effective pixel aspect ratios are used even for standard definition digital video originated in digital form rather than converted from analog. For more details refer to themain article.

In analog images such as film there is no notion of pixel, nor notion of SAR or PAR, and "aspect ratio" refers unambiguously to DAR. Actual displays do not generally have non-square pixels, though digital sensors might; they are rather a mathematical abstraction used in resampling images to convert between resolutions.

Non-square pixels arise often in early digital TV standards, related to digitalization of analog TV signals – whose horizontal and vertical resolutions differ and are thus best described by non-square pixels – and also in some digital videocameras and computerdisplay modes,such asColor Graphics Adapter(CGA). Today they arise particularly intranscodingbetween resolutions with different SARs.

DAR is also known asimage aspect ratioandpicture aspect ratio,though the latter can be confused withpixelaspect ratio; PAR is also known assample aspect ratio,though it can also be confused withstorageaspect ratio.

Previous and currently used aspect ratios

For a listing of computer resolutions and aspect ratios, seelist of common resolutions.

For a full listing of film formats, including their aspect ratios, seelist of motion picture film formats.

Comparison of several film aspect ratios with the heights forced to be equal images

1:2.32

The firsttelevisionaspect ratio, used byJohn Logie Baird's 30-line mechanical television in the early 1930s.

1.19:1=19:16

Sometimes referred to as theMovietoneratio, this ratio was used briefly during the transitional period when the film industry was converting to sound, from 1926 to 1932 approx. It is produced by superimposing an optical soundtrack over a full-gate 1.3aperture in printing, resulting in an almost square image. Films shot in this ratio are often projected or transferred to video incorrectly using a 1.375:1 mask or squashed to 1.375:1. Examples of films shot in the Movietone ratio includeSunrise: A Song of Two Humans,M,Hallelujah!,and, significantly more recently,The Lighthouse.A trend arising from the widespread use of smartphones isvertical videothat is intended for viewing inportrait mode.The format was popularized in particular by apps such asSnapchat,Instagram,andYouTube—which all offer means for publishing vertical videos as content andadvertising.

1.25:1=5:4

The once-popular aspect for larger format computer monitors, especially in the guise of mass-produced 17 "and 19" LCD panels or 19 "and 21" CRTs, using 1280×1024 (SXGA) or similar resolutions. Notably one of the few popular display aspect ratios narrower than 4:3, and one popularised by business (CAD, DTP) rather than entertainment use, as it is well-suited to full-page layout editing. Historically, 5:4 was also the original aspect ratio of early 405-line television broadcasts, which progressed to a wider 4:3 as the idea of broadcasting cinema films gained traction.

1.33:1=4:3=12:9

35 mm original silent film ratio, today commonly known in TV andvideoas 1.33:1. Also standard ratio forMPEG-2video compression. This format is still used in many personal video cameras today and has influenced the selection or design of other aspect ratios. It is the standardSuper 35mm ratio.

1.37:1=48:35

16 mm and 35 mm standard ratio.

1.375:1=11:8

35 mm full-screen sound film image, nearly universal in films between 1932 and 1953. Officially adopted as theAcademy ratioin 1932 byAMPAS.Rarely used in theatrical context nowadays, but occasionally used in other contexts.

1.43:1

IMAXformat. IMAX productions use 70 mm wide film (the same as used for 70 mm feature films), but the film runs through the camera and projector horizontally. This allows for a physically larger area for each image.

1.5:1=3:2

The aspect ratio of 35 mm film used for still photography when eight perforations are exposed. Also the native aspect ratio ofVistaVision,for which the film runs horizontally. Used on theChromeOS-basedChromebook Pixelnotebook PC, theGame Boy Advanceportable game console, mostly allMicrosoft Surface2-in-1 laptopsandSurface Studio.

1.5:1=14:9

Widescreen aspect ratio sometimes used in shooting commercials etc. as a compromise format between 4:3 and 16:9. When converted to a 16:9 frame, there is slightpillarboxing,while conversion to 4:3 creates slightletterboxing.All widescreen content onABC Family's SD feed until January 2016 was presented in this ratio.

1.6:1=16:10=8:5

Widescreen computer monitor ratio (for instance, 1920×1200 resolution).

1.66:1or1.6:1=5:3=15:9

Early 35 mm widescreen ratio, originally invented byParamount Pictures,later a standard among several European countries.It is also the native Super 16 mm frame ratio. Sometimes this ratio is rounded to 1.67:1. From the late 1980s to the early 2000s,Walt Disney Feature Animation'sCAPS programanimated their features in the 1.6:1 ratio (a compromise between the 1.85:1 theatrical ratio and the 1.33:1 ratio used for home video); this format is also used by theNintendo 3DS's top screen.

1.75:1=7:4

35 mm widescreen aspect ratio used by The Metro Goldwyn Mayer Company and The Warner Brothers Company from 1953 to 1955 and since abandoned and The Walt Disney Company has cropped the old classic post-1950s 1.33:1 fullscreen films to the 1.75:1 widescreen aspect ratio of their DVDs includingThe Jungle Book.

1.77:1=16:9=4²:3²

Video widescreen standard, used inhigh-definition television,one of three ratios specified forMPEG-2video compression. Also used increasingly in personal video cameras. Sometimes this ratio is rounded to 1.78:1.

1.85:1~37:20

35 mm American and British widescreen standard for theatrical film. Introduced byUniversal Picturesin May 1953. Projects approximately threeperforations( "perfs" ) of image space per four-perf frame; films can be shot in3-perfto save cost of film stock. Also the ratio of Ultra 16 mm. One of two common formats indigital cinema,where it is called "flat".

1.875:1=15:8

HDTV ratio used bySilicon Graphicscomputers in the 1990s, with the resolution being specified as 1920×1024.

1.9:1

SMPTE/DCIdigital cinema basic resolution container aspect ratio. Exact ratio is 256:135 but it is commonly referred to as 1.9:1or 1.90:1and sometimes 1.896:1.Used byDiao Yinan'sThe Wild Goose Lake.

2:1=18:9

Recently popularized by theRed Digital Cinema.Original SuperScope ratio, also used inUnivisium.Used as a flat ratio for some American studios in the 1950s and abandoned in the 1960s. Also used in recent mobile phones such as theLG G6,Google Pixel 2 XL,HTC U11+,Xiaomi MIX 2S, andHuawei Mate 10 Pro,while theSamsung Galaxy S8,Note 8,andS9use the similar 18.5:9 ratio.

2.165:1~ 28:13

Used by the screens of someiPhonemodels since 2017, including theiPhone X,XS, XS Max, 11, 11 Pro, and 11 Pro Max.

2.208:1~ 11:5

70 mm standard. Originally developed forTodd-AOin the 1950s. Specified inMPEG-2as 2.20:1, but hardly used.

2.35:1~ 47:20

35 mm anamorphic prior to 1970, used byCinemaScope( "'Scope" ) and earlyPanavision.The anamorphic standard has subtly changed so that contemporary anamorphic productions are actually 2.39:1,but often referred to as 2.35:1 anyway, due to old convention.(Anamorphic refers to the compression of the image on film to maximize an area slightly taller than standard4-perfAcademyaperture, but presents the widest of aspect ratios.)All IndianBollywoodfilms released after 1972 are shot in this standard for theatrical exhibition.

2.370:1=64:27=4³:3³

TVs were produced with this aspect ratio between 2009 and 2012and marketed as "21:9 cinema displays".But this aspect ratio is still seen on some higher-end monitors, which are sometimes called UltraWide monitors.

2.39:1~ 43:18=21+1⁄2:9

35 mm anamorphic from 1970 onwards. Aspect ratio of currentanamorphic widescreentheatrical viewings, commercials, and some music videos. Often commercially branded asPanavisionformat or "'Scope".One of two common formats indigital cinema,where it is called "scope".

2.4:1=12:5= 21:9

Rounded notation of 2.39:1 also known as 2.40:1. All film releases may use 800 lines of the 1920×800 resolution resulting in the 2.40:1 aspect ratio of Blu-ray Disc.

2.55:1~ 51:20

Original aspect ratio ofCinemaScopebefore optical sound was added to the film in 1954. This was also the aspect ratio ofCinemaScope 55.

2.59:1~ 70:27

Cineramaat full height (three specially captured 35 mm images projected side by side into one composite widescreen image).

2.6:1=8:3=24:9

Full-frameoutput from Super 16 mm negative when an anamorphic lens system has been used. Effectively, an image that is of the ratio 24:9 is squashed onto the native 15:9 aspect ratio of a Super 16 mm negative. Also used byKirill SerebrennikovforLeto(2018).

2.76:1=69:25

Ultra Panavision 70/MGM Camera 65(65 mm with 1.25× anamorphic squeeze). Used only on a handful of films between 1957 and 1966 and some in the 2010s, for some sequences ofHow the West Was Won(1962) with a slight crop when converted to three-stripCinerama,and films such asIt's a Mad, Mad, Mad, Mad World(1963) andBen-Hur(1959). More recently,Quentin Tarantinoused it forThe Hateful Eight(2015);Gareth Edwardsused the process for shootingRogue One(2016), but the image was cropped to 2.39:1 in post; Edwards would later shootThe Creator(2023) in this ratio.

3.5:1=32:9

In 2017, Samsung and Phillips announced "Super UltraWide displays", with aspect ratio of 32:9.

3.6:1=18:5

In 2016, IMAX announced the release of films in "Ultra-WideScreen 3.6" format,with an aspect ratio of 36:10.Ultra-WideScreen 3.6 video format didn't spread, as cinemas in an even wider ScreenX 270° format were released.

4:1

Rare use ofPolyvision,three 35 mm 1.3:1 images projected side by side. First used in 1927 onAbel Gance'sNapoléon.

12:1

Circle-Vision 360°developed by theWalt Disney Companyin 1955 for use inDisneyland.Uses nine 4:3 35 mm projectors to show an image that completely surrounds the viewer. Used in subsequent Disney theme parks and other past applications.

Aspect ratio releases

Original aspect ratio (OAR)

Original Aspect Ratio(OAR) is ahome cinematerm for the aspect ratio or dimensions in which afilmor visual production was produced, as envisioned by the people involved in the creation of the work. As an example, the filmGladiatorwas released to theaters in the 2.40:1 aspect ratio. It was filmed inSuper 35and, in addition to being presented in cinemas and television in theOriginal Aspect Ratio(OAR) of 2.40:1, it was also broadcast without thematte,altering the aspect ratio to the television standard of 1.33:1. Because of the varied ways in which films are shot, IAR (Intended Aspect Ratio) is a more appropriate term, but is rarely used.

Modified aspect ratio (MAR)

Modified Aspect Ratio(MAR) is a home cinema term for the aspect ratio or dimensions in which a film was modified to fit a specific type of screen, as opposed to original aspect ratio. Modified aspect ratios are usually either 1.33:1 (historically), or (with the advent of widescreen television sets) 1.43:1 aspect ratio. 1.33:1 was the modified aspect ratio used historically on 4:3 broadcast television and home videotape formats such as VHS and Beta. A modified aspect ratio transfer is achieved by means ofpan and scanor EAR (Expanded Aspect Ratio)/open matte,the latter meaning removing the cinematic matte from a 2.40:1 film to open up the full 1.33:1 frame or from 2.40:1 to 1.43:1 inIMAX.Another name for it is rescaled aspect ratio.

Problems in film and television

Awindowboxedimage

Multiple aspect ratios create additional burdens on directors and the public, and confusion among TV broadcasters. It is common for a widescreen film to be presented in an altered format (cropped,letterboxedor expanded beyond the original aspect ratio). It is also not uncommon forwindowboxingto occur (when letterbox and pillarbox happen simultaneously). For instance, a 16:9 broadcast could embed a 4:3 commercial within the 16:9 image area. A viewer watching on a standard 4:3 (non-widescreen) television would see a 4:3 image of the commercial with 2 sets of black stripes, vertical and horizontal (windowboxing or the postage stamp effect). A similar scenario may also occur for a widescreen set owner when viewing 16:9 material embedded in a 4:3 frame, and then watching that in 16:9.Active Format Descriptionis a mechanism used in digital broadcasting to avoid this problem. It is also common that a 4:3 image is stretched horizontally to fit a 16:9 screen to avoidpillarboxingbut distorts the image so subjects appear short and fat.

Both PAL and NTSC have provision for some data pulses contained within the video signal used to signal the aspect ratio (See ITU-R BT.1119-1 –Widescreen signalingfor broadcasting). These pulses are detected by television sets that have widescreen displays and cause the television to automatically switch to 16:9 display mode. When 4:3 material is included (such as the aforementioned commercial), the television switches to a 4:3 display mode to correctly display the material. Where a video signal is transmitted via a EuropeanSCARTconnection, one of the status lines is used to signal 16:9 material as well.

Still photography

Common aspect ratios instill photographyinclude:

• 1:1 (1.0:1)
• 5:4 (1.25:1)
• 4:3 (1.3:1)
• 3:2 (1.5:1)
• 5:3 (1.6:1)
• 16:9 (1.77:1 or 1.78:1)
• 3:1 (3.0:1)

Many digital still cameras offer user options for selecting multiple image aspect ratios. Some achieve this through the use of multi-aspect sensors (notablyPanasonic), while others simply crop their native image format to have the output match the desired image aspect ratio.

1:1

1:1 is the classic Kodak image, and is available as a choice in some digital still cameras, and hearkens back to the days of film cameras when the square image was popular with photographers using twin lens reflex cameras. These medium format cameras used120 filmrolled onto spools. The 6 × 6 cm image size was the classic 1:1 format in the recent past. 120 film can still be found and used today. ManyPolaroidinstant filmswere designed as square formats. Furthermore, up until August 2015, photo-sharing siteInstagramonly allowed users to upload images in 1:1 format. In 2017, Fujifilm added the 1:1Instax Squareformat to their lineup of instant film cameras.

5:4

Common in large and medium format photography ('6x7' cameras, actual size 56 mm × 70 mm (2.2 in × 2.8 in)), which fits the common print paper size of 8 in × 10 in (20.3 cm × 25.4 cm) without cropping and is still in common use for prints from digital cameras.

4:3

4:3 is used by most digitalpoint-and-shoot cameras,Four Thirds system,Micro Four Thirds systemcameras andmedium format645 cameras. The 4:3 digital format popularity was developed to match the then prevailing digital displays of the time, 4:3 computer monitors. This aspect ratio is also wider than the popular 16:9, thus being very popular among different E-Sports tournaments. The next several formats have their roots in classic film photography image sizes, both the classic 35 mm film camera, and the multiple formatAdvanced Photo System(APS) film camera. The APS camera was capable of selecting any of three image formats, APS-H ( "High Definition" mode), APS-C ( "Classic" mode) and APS-P ( "Panoramic" mode).

3:2

3:2 is used by classic35 mm filmcameras using a 36 mm × 24 mm image size, and their digital derivatives represented byDSLRs.Typical DSLRs come in two flavors, the so-called professional "full frame" (36 mm × 24 mm) sensors and variations of smaller, so called "APS-C" sensors. The term "APS" is derived from another film format known as APSand the "-C" refers to "Classic" mode, which exposed images over a smaller area (25.1 mm × 16.7 mm) but retaining the same "classic" 3:2 proportions as full frame 35 mm film cameras.

When discussing DSLRs and their non-SLR derivatives, the term APS-C has become an almost generic term. The two major camera manufacturersCanonandNikoneach developed and established sensor standards for their own versions of APS-C sized and proportioned sensors. Canon actually developed two standards, APS-C and a slightly larger area APS-H (not to be confused with the APS-H film format), while Nikon developed its own APS-C standard, which it callsDX.Regardless of the different flavors of sensors, and their varying sizes, they are close enough to the original APS-C image size, and maintain the classic 3:2 image proportions that these sensors are generally known as an "APS-C" sized sensor.

The reason for DSLR's image sensors being the flatter 3:2 versus the taller point-and-shoot 4:3 is that DSLRs were designed to match the legacy 35 mm SLR film, whereas the majority of digital cameras were designed to match the predominant computer displays of the time, with VGA, SVGA, XGA and UXGA all being 4:3. Widescreen computer monitors did not become popular until the advent ofHDTV,which uses a 16:9 image aspect ratio.

16:9

Known as APS-H (30.2 mm × 16.7 mm), with the "-H" denoting "High Definition", the 16:9 format is also the standard image aspect ratio for HDTV. 16:9 is gaining popularity as a format in all classes of consumer still cameras which also shoot High Definition (HD)video.When still cameras have an HD video capability, some can also record stills in the 16:9 format, ideal for display on HD televisions and widescreen computer displays.

3:1

3:1 is yet another format that can find its roots in the APS film camera. Known as APS-P (30.2 × 9.5 mm), with the -P "denoting" Panorama ", the 3:1 format was used forpanoramaphotography. The APS-P panorama standard is the least adhered to any APS standard, and panoramic implementation varies with by manufacturer on different cameras, with the only commonality being that the image is much longer than it is tall, in the classic "panorama" style.

Commonprint sizesin the United States (ininches) include 4×6 (1.5), 5×7 (1.4), 4×5 and 8×10 (1.25), and 11×14 (1.27);large formatcameras typically use one of these aspect ratios.Medium-formatcameras typically have format designated by nominal sizes in centimeters (6×6, 6×7, 6×9, 6×4.5), but these numbers should not be interpreted as exact in computing aspect ratios. For example, the usable height of120-format roll filmis 56mm, so a width of 70mm (as in 6×7) yields an aspect ratio of 4:5 — ideal for enlarging to make an 8×10 "portrait. Print sizes are usually defined by their portrait dimensions (tall) while equipment aspect ratios are defined by their landscape dimensions (wide, flipped sideways). A good example of this a 4×6 print (6 inch wide by 4 inch tall landscape) perfectly matches the 3:2 aspect ratio of a DSLR/35 mm, since 6/2=3 and 4/2=2.

For analog projection of photographic slides, projector and screen use a 1:1 aspect ratio, supporting horizontal and vertical orientation equally well. In contrast, digital projection technology typically supports vertically oriented images only at a fraction of the resolution of landscape-oriented images. For example, projecting a digital still image having a 3:2 aspect ratio on a 16:9 projector employs 84.3% of available resolution in horizontal orientation, but only 37.5% in vertical orientation.

See also

• Active Format Description
• Index of articles related to motion pictures
• Paper size
• Shoot and protect
• Glossary of video terms
• Ultrawide formats

Sources

On aspect ratios

• "NEC Monitor Technology Guide".Archived fromthe originalon 2006-05-21.Retrieved2006-07-24.
• The Letterbox and Widescreen Advocacy Page
• American Widescreen Museum
• Widescreen Apertures and Aspect Ratios
• Aspect – combined aspect ratio, frame size and bitrate calculatorat theWayback Machine(archived December 7, 2013)
• Aspect Ratios Explained:Part 1Part 2Archived2013-06-04 at theWayback Machine
• Explanation of TV Aspect Ratio format description codes
• IMDb – Number of DVDs for each aspect ratioat theWayback Machine(archived June 24, 2009)
• SCADplus: 16:9 Action plan for the television in the 16:9 screen format – European Union