Anamorphic format


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. It also refers to the projection format in which a distorted image is "stretched" by an anamorphic projection lens to recreate the original aspect ratio on the viewing screen. The word anamorphic and its derivatives stem from the Greek anamorphoun, compound of morphé with the prefix aná. In the late 1990s and 2000s, anamorphic lost popularity in comparison to "flat" formats such as Super 35 with the advent of digital intermediates; however in the years since digital cinema cameras and projectors have become commonplace, anamorphic has experienced a considerable resurgence of popularity, due in large part to the higher base ISO sensitivity of digital sensors, which facilitates shooting at smaller apertures.

History

The process of anamorphosing optics was developed by Henri Chrétien during World War I to provide a wide angle viewer for military tanks. The optical process was called Hypergonar by Chrétien and was capable of showing a field of view of 180 degrees. After the war, the technology was first used in a cinematic context in the short film Construire un Feu in 1927 by Claude Autant-Lara.
In the 1920s, phonograph and motion picture pioneer Leon F. Douglass also created special effects and anamorphic widescreen motion picture cameras. However, how this relates to the earlier French invention, and later development, is unclear.
Anamorphic widescreen was not used again for cinematography until 1952 when Twentieth Century-Fox bought the rights to the technique to create its CinemaScope widescreen technique. CinemaScope was one of many widescreen formats developed in the 1950s to compete with the popularity of television and bring audiences back to the cinemas. The Robe, which premiered in 1953, was the first feature film released that was filmed with an anamorphic lens.

Development

The introduction of anamorphic widescreen arose from a desire for wider aspect ratios that maximised overall image detail while retaining the use of standard cameras and projectors. The modern anamorphic format has an aspect ratio of 2.39:1, meaning the picture's width is 2.39 times its height,. The older Academy format 35 mm film has an aspect ratio of 1.375:1, which, when projected, is not as wide.
Anamorphic widescreen was a response to a shortcoming in the non-anamorphic spherical widescreen format. With a non-anamorphic lens, the picture is recorded onto the film negative such that its full width fits within the film's frame, but not its full height. A substantial part of the frame area is thereby wasted, being occupied by a portion of the image which is subsequently matted-out and so not projected, in order to create the widescreen image.
To increase overall image detail, by using all the available area of the negative for only that portion of the image which will be projected, an anamorphic lens is used during photography to compress the image horizontally, thereby filling the full frame's area with the portion of the image that corresponds to the area projected in the non-anamorphic format. Up to the early 1960s, three major methods of anamorphosing the image were used: counter-rotated prisms, curved mirrors in combination with the principle of Total Internal Reflection, and cylindrical lenses. Regardless of method, the anamorphic lens projects a horizontally squeezed image on the film negative. This deliberate geometric distortion is then reversed on projection, resulting in a wider aspect ratio on-screen than that of the negative's frame.

Equipment

An anamorphic lens consists of a regular spherical lens, plus an anamorphic attachment that does the anamorphosing. The anamorphic element operates at infinite focal length, so that it has little or no effect on the focus of the primary lens it's mounted on but still anamorphoses the optical field. A cameraman using an anamorphic attachment uses a spherical lens of a different focal length than they would use for Academy format, and the anamorphic attachment squeezes the image to half-width. Other anamorphic attachments existed which would expand the image in the vertical dimension, so that a frame twice as high as it might have been filled the available film area. In either case, since a larger film area recorded the same picture the image quality was improved.
The distortion introduced in the camera must be corrected when the film is projected, so another lens is used in the projection booth that restores the picture back to its correct proportions to restore normal geometry. The picture is not manipulated in any way in the dimension that is orthogonal to the one anamorphosed.
It may seem that it would be easier to simply use a wider film for recording movies. However, since 35 mm film was already in widespread use, it was more economically feasible for film producers and exhibitors to simply attach a special lens to the camera or projector, rather than invest in an entirely new film format, which would require new cameras, projectors, editing equipment and so forth.

Naming

was an earlier attempt to solve the problem of high-quality widescreen imaging, but anamorphic widescreen eventually proved more practical. Cinerama consisted of three simultaneously projected images side-by-side on the same screen. However, in practice the images never blended together perfectly at the edges. The system also suffered from various technical drawbacks, in that it required three projectors, a 6-perf-high frame, four times as much film, and three cameras, plus a host of synchronization problems. Nonetheless, the format was popular enough with audiences to trigger off the widescreen developments of the early 1950s. A few films were distributed in Cinerama format and shown in special theaters, but anamorphic widescreen was more attractive to the Studios since it could realize a similar aspect ratio and without the disadvantages of Cinerama's complexities and costs.
The anamorphic widescreen format in use today is commonly called 'Scope', or 2.35:1. Filmed in Panavision is a phrase contractually required for films shot using Panavision's anamorphic lenses. All of these phrases mean the same thing: the final print uses a 2:1 anamorphic projector lens that expands the image by exactly twice the amount horizontally as vertically. This format is essentially the same as that of CinemaScope, except for some technical developments, such as the ability to shoot closeups without any facial distortion.

Optical characteristics

There are artifacts that can occur when using an anamorphic camera lens that do not occur when using an ordinary spherical lens. One is a kind of lens flare that has a long horizontal line, usually with a blue tint, and is most often visible when there is a bright light in the frame, such as from car headlights, in an otherwise dark scene. This artifact is not always considered a problem., and even has become associated with a certain cinematic look, and often emulated using a special effect filter in scenes shot with a non-anamorphic lens. Another common aspect of anamorphic lenses is that light reflections within the lens are elliptical, rather than round as in ordinary cinematography. Additionally, wide angle anamorphic lenses of less than 40 mm focal length produce a cylindrical perspective, which some directors and cinematographers, particularly Wes Anderson, use as a stylistic trademark.
, as simulated by this stitched panorama of Cavendish House, Leicester. Contrast the straight vertical plane with the curved horizontal plane.
Another characteristic of anamorphic lenses, because they stretch the image vertically, is that out-of-focus elements tend to blur more in the vertical direction. An out-of-focus point of light in the background appear as a vertical oval rather than as a circle. When the camera shifts focus, there is often a noticeable effect whereby objects appear to stretch vertically when going out of focus. However, the commonly cited claim that anamorphic lenses produce a shallower depth of field is not entirely true. Because of the cylindrical element in the lens, anamorphic lenses take in a horizontal angle of view twice as wide as a spherical lens of the same focal length. Because of this, cinematographers often use a 50 mm anamorphic lens when they would otherwise use a 25 mm spherical lens, or a 70 mm rather than a 35 mm, and so on.
A third characteristic, particularly of simple anamorphic add-on attachments, is "anamorphic mumps". For reasons of practical optics, the anamorphic squeeze is not uniform across the image field in any anamorphic system. This variation results in some areas of the film image appearing more stretched than others. In the case of an actor's face, when positioned in the center of the screen faces look somewhat like they have the mumps, hence the name for the phenomenon. Conversely, at the edges of the screen actors in full-length view can become skinny-looking. In medium shots, if the actor walks across the screen from one side to the other, he will increase in apparent girth. Early CinemaScope presentations in particular suffered from this. Panavision was the first company to produce an anti-mumps system in the late 1950s.
Panavision used a second lens which was mechanically linked to the focus position of the primary lens. This changed the anamorphic ratio as the focus changed, resulting in the area of interest on-screen having a normal-looking geometry. Later cylindrical lens systems used, instead, two sets of anamorphic optics: one was a more robust "squeeze" system, which was coupled with a slight expansion sub-system. The expansion sub-system was counter-rotated in relation to the main squeeze system, all in mechanical interlinkage with the focus mechanism of the primary lens: this combination changed the anamorphic ratio and minimized the effect of anamorphic mumps in the area of interest in the frame. Although these techniques were regarded as a fix for anamorphic mumps, they were actually only a compromise. Cinematographers still had to frame scenes carefully to avoid the recognizable side-effects of the change in aspect ratio.

Recent use

Although the anamorphic widescreen format is still in use as a camera format, it has been losing popularity in favour of flat formats, mainly Super 35. The decline in popularity can be attributed to the artifacts, distortions, speed, and expenses.
An anamorphic lens is often slower than a similar spherical lens, and thus requires more light and makes shooting low-light scenes more difficult. The anamorphic-scope camera format does not preserve any of the image above or below the frame, so it may not transfer as well to narrower aspect ratios, such as or for full screen television, and would have to be pan and scanned as a result. Film grain has become less of a concern because of the availability of higher-quality film stocks and digital intermediates, although anamorphic format - due to its use of the full negative frame to record a smaller image – always yields higher definition than non-anamorphic format.
Anamorphic scope as a printed film format, however, is well established as a standard for widescreen projection. Regardless of the camera formats used in filming, distributed prints of a film with a 2.39:1 theatrical aspect ratio is always in anamorphic widescreen format. Due to many movie theaters around the world not needing to invest in special equipment to project this format, it has become standard equipment in many cinemas.

[|Aspect ratio]

One common misconception about the anamorphic format concerns the actual width number of the aspect ratio, as 2.35, 2.39 or 2.4. Since the anamorphic lenses in virtually all 35 mm anamorphic systems provide a 2:1 squeeze, one would logically conclude that a full academy gate would lead to a aspect ratio when used with anamorphic lenses. Due to differences in the camera gate aperture and projection aperture mask sizes for anamorphic films, however, the image dimensions used for anamorphic film vary from flat counterparts. To complicate matters, the SMPTE standards for the format have varied over time; to further complicate things, pre-1957 prints took up the optical soundtrack space of the print, which made for a ratio.
The initial SMPTE definition for anamorphic projection with an optical sound track down the side ANSI PH22.106-1957 was issued in December 1957. It standardized the projector aperture at, which gives an aspect ratio of c.. The aspect ratio for this aperture, after a 2× unsqueeze, is, which rounded to the commonly used value '.
A new definition issued in October 1971 as ANSI PH22.106-1971. It specified a slightly smaller vertical dimension of for the projector aperture, to help make splices less noticeable to film viewers. After unsqueezing, this would yield an aspect ratio of c..
Four-perf anamorphic prints use more of the negative's available frame area than any other modern format, which leaves little room for splices. As a consequence, a bright line flashed onscreen when a splice was projected, and theater projectionists had been narrowing the vertical aperture to hide these flashes even before 1971. This new projector aperture size,, aspect ratio, made for an un-squeezed ratio of
'. This is commonly referred to by the rounded value or.
The most recent revision, SMPTE 195-1993, was released in August 1993. It slightly altered the dimensions so as to standardize a common projection aperture width for all formats, anamorphic and flat. The projection aperture height was also reduced by in this modern specification to, aspect ratio, which is commonly rounded to, to retain the un-squeezed ratio of. The camera's aperture remained the same, only the height of the "negative assembly" splices changed and, consequently, the height of the frame changed.
Anamorphic prints are still often called 'Scope' or 2.35 by projectionists, cinematographers, and others working in the field, if only by force of habit. 2.39 is in fact what they generally are referring to, which is itself usually rounded up to 2.40. With the exception of certain specialist and archivist areas, generally 2.35, 2.39 and 2.40 mean the same to professionals, whether they themselves are even aware of the changes or not.

Lens makers and corporate trademarks

There are numerous companies that are known for manufacturing anamorphic lenses. The following are the most well known in the film industry:

Origination

Although many films projected anamorphically have been shot using anamorphic lenses, there are often aesthetic and technical reasons that make shooting with spherical lenses preferable. If the director and cinematographer still wish to retain the 2.40:1 aspect ratio, anamorphic prints can be made from spherical negatives. Because the 2.40:1 image cropped from an Academy ratio 4-perf negative causes considerable waste of frame space, and since the cropping and anamorphosing of a spherical print requires an intermediate lab step, it is often attractive for these films to use a different negative pulldown method usually in conjunction with the added negative space Super 35 affords.
However, with advancements in digital intermediate technology, the anamorphosing process can now be completed as a digital step with no degradation of image quality. Also, 3-perf and 2-perf pose minor problems for visual effects work. The area of the film in 4-perf work that is cropped out in the anamorphosing process nonetheless contains picture information that is useful for such visual effects tasks as 2D and 3D tracking. This mildly complicates certain visual effects efforts for productions using 3-perf and 2-perf, making anamorphic prints struck digitally from center cropped 4-perf Super 35 the popular choice in large budget visual effects driven productions.