Aspect ratio (image)

With television, DVD and Blu-ray, 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 (zooming and cropping), 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 in Wide Zoom mode).

The motion picture industry convention assigns a value of 1 to the image's height; an anamorphic frame (since 1970, approximately 2.39:1) is often incorrectly described (rounded) as either 2.4:1 or 2.40:1.

The "Academy ratio" of 1.375:1 was used for all cinema films in the sound era until 1953 (with the release of George Stevens' Shane in 1.6:1).

Hollywood responded by creating a large number of widescreen formats: CinemaScope (up to 2.6:1), Todd-AO (2.20:1), and VistaVision (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.

[5] 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.

The format was briefly revived by Lucasfilm in 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).

In that sense, square video was popularized by mobile apps such as Instagram and Vine and has since been supported by other major social platforms including Facebook and X.

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).

[9] 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.

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.

Many digital video cameras have the capability to record in 16:9 (= 42:32), and 16:9 is the only widescreen aspect ratio natively supported by the DVD standard.

[22] Univisium has gained little traction in the theatrical film market, but has recently been used by Netflix and Amazon Video for productions such as House of Cards and Transparent, 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.

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.

The following formulae can be used to find the height (h), width (w) and area (A), where r stands for ratio, written as a fraction of x by y, and d for diagonal length.

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.

Because of the varied ways in which films are shot, IAR (Intended Aspect Ratio) is a more appropriate term, but is rarely used.

1.33:1 was the modified aspect ratio used historically on 4:3 broadcast television and home videotape formats such as VHS and Beta.

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, letterboxed or expanded beyond the original aspect ratio).

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.

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.

16:9 is gaining popularity as a format in all classes of consumer still cameras which also shoot High Definition (HD) video.

Common print sizes in the United States (in inches) include 4×6 (1.5), 5×7 (1.4), 4×5 and 8×10 (1.25), and 11×14 (1.27); large format cameras typically use one of these aspect ratios.

Medium-format cameras 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 of 120-format roll film is 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.

For analog projection of photographic slides, projector and screen use a 1:1 aspect ratio, supporting horizontal and vertical orientation equally well.