Aspect ratio of aspect ratio (image)

The size of the frame in the movie is determined by the actual size recorded between the perforations of the film. 35mm film is often used when shooting movies. The so-called 35mm refers to the width of the film, and there are gear holes on both sides of the film. According to the universal standard proposed by William Dickinson and Edison in 1892, the length of each frame is set to the height of four buckle gear holes. The film itself is 35mm wide, but the width between the perforations is 24.89mm and the height is 18.67mm.

Film terminology

In the film industry, it is customary to reduce the height of the image ratio to 1. In this way, a 2.40:1 horizontal image only needs to be described as "240" . The most commonly used display ratios in American cinemas are 1.85:1 and 2.39:1. Some European countries use 1.66:1 as the widescreen standard. 1.37:1 was the ratio shown in all cinemas until 1953 when 1.85:1 replaced it as the standard.

Movie camera system

The development of the camera system ultimately must still be subject to the size of the film perforations and the space that must be reserved for the sound effects track. VistaVision is a wide-screen initiative developed by Paramount Pictures. It uses standard 35mm size film, but the film runs sideways instead of straight, and the perforations are above and below the straightened frame. Instead of left and right, the result is that a larger horizontal screen can be used, which is twice as wide as a normal image, and the height is relatively reduced. But when projected, the VistaVision system's output ratio of 1.5 still had to be cropped to 1.85 and reversed using the lens back to the original straight print (i.e., a 35mm film image with four perforations high) before it could be projected. Although the format was revived by Lucasfilm in the 1970s for special effects requirements (image degradation during optical conversion was necessary for multi-layer compositing), by this time there were better cameras, lenses, and a large amount of standard 35mm film. Inventory was consumed, and switching between vertical and horizontal lines created additional costs for flushing, and VistaVision was widely viewed as an obsolete system. However, this conversion was later used by IMAX and their 70mm films. Super 16 mm film is used by many television productions because of its low price. Since there is no need to reserve space for sound effects tracks (it is not originally used for projection but for output as images), its ratio is 1.66:1, close to 16:9 of 1.78. Because it can also be enlarged to 35mm film for projection, it can also be used to shoot movies. Diagonal comparison of three common aspect ratios (black circle). The widest and shortest blue frame (2.39:1) is the commonly used aspect ratio for movies. The green frame (16:9) and the nearly square red frame (4:3) are the standard ratios commonly used in televisions. Five standard ratios represented by diagonals: 16:9, 16:10, 3:2, 4:3, 5:4.

4:3 standard

4:3 is the oldest ratio, it has been around since the invention of television, is still in use today, and is used in many computers on the monitor. In terms of American movies, Hollywood movies entered the era of wide screen (1.85:1) in the 1950s, flaunting higher visual enjoyment in order to regain audiences who had switched from cinemas to television.

16:9 Standard

16:9 is the international standard for high-definition television, used in Australia, Japan, Canada and the United States, as well as European satellite television and some non-HD wide screen television (EDTV) PAL-plus. Japan's Hi-Vision originally used 5:3, but it changed because the international standards organization proposed a new ratio of 5:3 (i.e. 16:9). 1.78:1 is to merge the different widescreen ratios used in the United States, Britain and Europe. Although both are 35 mm film, the former is 1.85 and the latter is 1.66:1. Many digital cameras today have the ability to shoot 16:9 footage. Widescreen DVD stretches the 16:9 picture to 4:3 for data storage, and adapts according to the TV's processing capabilities. If the TV supports widescreen, then the image can be restored and played. If it does not support it, the DVD will The player cuts the picture and sends it to the TV. Wider ratios such as 1.85:1 or 2.40:1 add black bars above and below the image. The European Union has organized the 16:9 Action Plan to accelerate the conversion to 16:9 signals. They have the same efforts on the PAL specification and the HD specification. The European Union ultimately raised 228 million euros for this plan. 1.19:1: Movietone, an early sound film using 35mm film, mostly shot in the 1920s and 1930s, especially in Europe. The optical sound track is placed on the side of the 1.33 frame, thus reducing the width of the frame.

"Academy Aperture" expands the film's usable area to 1.37. The best examples of this proportion are Fritz Lang's photographs of M and The Testament of Dr. Mabuse. In today's landscape aspect ratios it is barely used.

1.25:1: This is the ratio commonly used in computers, 1280x1024, which is the native resolution of many LCD monitors. It is also the ratio of 4x5 film developed prints. Early British horizontal 405 wire specifications used this ratio from the 1930s to the 1950s until superseded by the more versatile 4:3.

1.33:1: 4:3, the original aspect ratio of 35 mm film without a sound track, commonly used on television and video alike. It is also the standard ratio for IMAX and MPEG-2 image compression.

1.37:1: 35 mm full-screen film with a sound track, almost universal from 1932 to 1953. As "academy ratio" it was established as a standard by the Academy of Motion Picture Arts in 1932 and is still used occasionally today. Also the ratio of standard 16 mm film.

1.43:1: The horizontal format of IMAX 70 mm film.

1.5:1: The ratio of 35 mm film used for still life photography. Also used for wider computer displays (3:2), used in Apple Computer's PowerBook G4 15.2-inch screen with a resolution of 1440x960. This ratio is also used in Apple Computer's iPhone products.

1.56:1: The widescreen 14:9 ratio. It is a compromise ratio between 4:3 and 16:9, often used for shooting commercials or images that will be shown on both screens, and the conversion between the two will only produce a small amount of cropping.

1.6:1: Computer widescreen ratio (8:5, but 16:10 is more commonly used), used for WSXGAPlus, WUXGA and other resolutions. It is very popular because it can display two complete pages at the same time (one page on the left and one on the left).

1.66:1: 35 mm European widescreen standard; also the ratio of Super 16 mm film (5:3, sometimes specified as 1.67).

1.75:1: The widescreen ratio of early 35 mm films, primarily used by Metro-Goldwyn-Mayer but has since been abandoned.

1.78:1: Widescreen standard, i.e. 16:9. Used in HDTV and MPEG-2 image compression.

1.85:1: The ratio of 35 mm film used in the United States and the United Kingdom for filming films shown in theaters. In the four-teeth frame, the picture occupies about three frames high. You can also directly use three frames to shoot to save film costs.

2:1: Used primarily by Universal Pictures in the 1950s and early 1960s, as well as some of Paramount Pictures' VistaVision films; also one of many SuperScope ratios. The DVD version of Apocalypse Now also uses this ratio.

2.2:1: 70 mm film standard. Developed in the 1950s for the Todd-AO film. There is also 2.21:1 which is stated in the MPEG-2 specification but is not used.

2.35:1: Horizontal image shot on 35 mm film before 1970, used by CinemaScope and early Panavision. Standards for landscape shooting have slowly changed, and modern landscape productions are actually 2.39:1, but are still referred to as 2.35:1 due to tradition. (Note that the so-called "anamorphic" refers to the degree of compression of the image on the film, which is limited to the "college area" within four frames, compared with other images with higher height.)

2.39:1 : 35 mm lateral images after 1970. Sometimes it is rounded up to 2.40. Movies that say they were shot on Panavision or Cinemascope systems indicate this ratio.

2.55:1: The original ratio of the CinemaScope system before adding a sound effect track. This is also the ratio of CinemaScope 55.

2.59:1: The full height ratio of the Cinerama system (three specially shot 35 mm films projected into one widescreen image).

2.76:1: MGM Camera 65 (65 mm film plus 1.25x lateral compression), only used in some films between 1956 and 1964, such as 1959's Ben -Hur).

4:1: Polyvision, using three channels of 35 mm film projected side by side simultaneously.

Only used in one film, Abel Gance's Napoléon (1927). Original Aspect Ratio (OAR) is a term used in home theater to refer to the aspect ratio of a film or image when it was originally produced - as the author envisioned it. For example, when Ghost Warrior was first shown in theaters, it used a 2.39:1 ratio. It was originally shot on Super 35 mm film and, apart from being shown in cinemas and on television, was broadcast unmatte to fit the 1.33:1 aspect ratio. Due to the various methods used to shoot movies, "intended aspect ratio" is a more precise term but is rarely used.

Modified Aspect Ratio (MAR) (Modified Aspect Ratio, MAR) is a term used in home theaters. It refers to the original length of the image that is changed by stretching, cropping or matte in order to adapt to a specific display. width ratio. The adapted aspect ratio is usually 1.33:1 or 1.78:1. The adapted aspect ratio of 1.33:1 was historically used by the VHS format. The matte method refers to, for example, when stretching from a 1.78 screen to a 1.33 screen, some parts will be lost. Since the subject of the screen is not necessarily in the center, it must be used to maintain the subject of the screen.

Comparison of two different ratios, using the same height 4:3

(1.33:1) 16:9

(1.78:1)