70 mm film

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70 mm film

70mm film (or 65mm film) is a wide high-resolution film gauge, with higher resolution than standard 35mm motion picture film format. As used in camera, the film is 65 mm (2.6 in) wide. For projection, the original 65mm film is printed on 70 mm (2.8 in) film. The additional 5mm are for magnetic strips holding four of the six tracks of sound. Although more recent 70mm prints now use digital sound encoding, the vast majority of 70 mm prints predate this technology. Each frame is five perforations tall, with an aspect ratio of 2.20:1. The vast majority of film theaters are unable to handle 70mm film, and so original 70mm films are shown with 35mm prints at these venues, in the regular Cinemascope / Panavision aspect ratio of 2.35:1.

History

Films formatted with a width of 70 mm have existed since the early days of the motion picture industry. The first 70 mm format film was most likely footage of the Henley Regatta, which was projected in 1896 and 1897, but may have been filmed as early as 1894. It required a specially built projector built by Herman Casler in Canastota, New York and had a ratio similar to full frame, with an aperture of 2.75 inches (70 mm) by 2 inches (51 mm).  There were also several film formats of various sizes from 50 to 68 mm which were developed from 1884 onwards, including Cinéorama (not to be confused with the entirely distinct "Cinerama" format), started in 1900 by Raoul Grimoin-Sanson. Two other formats, Panoramica and 20th Century Fox's Grandeur, began distribution in 1929 and 1930, respectively.

The "Todd-AO" format, introduced with the film Oklahoma! in October 1955, popularized the format for use in feature length films. The original version of the Todd-AO process used a frame rate of 30 per second, 25% faster than the 24 frames per second that was (and is) the standard. Due to the costs of 70 mm film and the expensive projection system and screen required to use the stock, distribution for films using the stock was limited, although this did not always hurt profits. Most 70 mm films were also re-released on 35 mm film for a wider distribution after the initial debut of the film. Lawrence of Arabia, made in 1962, My Fair Lady, made in 1964, and The Sound of Music, made in 1965, are well-known films widely shown in 70 mm format with a general release in 35 mm format.

By the 1980s and 90s, films shot on 65 mm stock were increasingly rare. With the advent of small, multi-cinema theaters and the availability of digital soundtrack systems for less expensive 35 mm film, large-format films were made less often, and not always shown in their original format. The 1996 Kenneth Branagh Hamlet, for example, was filmed in Super Panavision 70, but largely screened in multiplex theaters in 35 mm reduction prints. Conversely, some 35 mm films made during the 1960s and 70s and intended for roadshow presentation were "blown up" to 70 mm size to make them appear more impressive on a larger screen. These included such films as Camelot (1967), Oliver! (1968), Cromwell (1970), and Fiddler on the Roof (1971). These enlargements did not have the sharpness and smoothness of 70 mm origination, but the larger prints were more stable when projected.

In recent years, the use of 65 mm negative film has been drastically reduced, in part due to the high cost of 65 mm raw stock and processing. The only recent films shot entirely on 65 mm stock are Kenneth Branagh's Hamlet (1996), Ron Fricke's, Baraka (1992), and its sequel Samsara (2011). Other films used 65 mm cameras sparingly, for selected scenes or special effects. Films with limited 65 mm footage include Terrence Malick's The New World (2005), Christopher Nolan's The Dark Knight (2008) (certain scenes in IMAX format), and Nolan's Inception (2011)^[1]. Samsara, in contrast, is the first feature-length film in over a decade to be shot entirely in 65 mm.

For home theater, VHS and DVD did not offer enough resolution to carry the full image quality captured by 70 mm film, and VHS and DVD video transfers were usually prepared from 35 mm reduction elements. The high-definition Blu Ray format, in contrast, can potentially reveal the quality advantage of 70 mm productions. Although telecine machines for 70 mm scanning are uncommon, high-resolution transfers from high-quality full-gauge elements can reveal impressive technical quality. Blu Ray transfers for certain classic films such as Ben Hur, The Sound of Music, and It's a Mad Mad Mad Mad World arguably approach the quality of real-world 70 mm projection.

There is currently one type of digital cinema camera with a 65 mm sensor, the Phantom 65. Otti International's Phil Kroll developed the world's first 65/70 mm telecine transfer system. This camera has been used in Hollywood to digitally master 70 and 65 mm films.

Uses of 70 mm

Ultra Panavision

An anamorphic squeeze combined with 65 mm film allowed for extremely wide aspect ratios to be used while still preserving quality. This was used in the 1959 film Ben-Hur, which was filmed with the MGM Camera 65 process at an aspect ratio of 2.76:1, one of the widest prints ever made. It required the use of a 1.25x anamorphic lens to horizontally compress the image, and a corresponding lens on the projector to uncompress it.

Special effects

Limited use of 65 mm film was revived in the late 1970s for some of the visual effects sequences in films like Close Encounters of the Third Kind, mainly because the larger negative did a better job than 35 mm negative of minimizing visible film grain during optical compositing. Since the 1990s, a handful of films (such as Spider-Man 2) have used it for this purpose, but the usage of digital intermediate for compositing has largely negated these issues. Digital intermediate offers other benefits such as lower cost and a greater range of available lenses and accessories to ensure a consistent look to the footage.

IMAX

A horizontal variant of 70 mm, with an even bigger picture area, is used for the high-performance IMAX format which uses a frame that is 15 perforations wide on 70 mm film. The Dynavision and Astrovision systems each use slightly less film per frame and vertical pulldown to save print costs while being able to project onto an IMAX screen. Both are rare, Astrovision largely in Japanese planetariums.

70 mm 3D Early use

The first commercial introduction of 70 mm single projector 3D was the 1967 release of Con la muerte a la espalda, a Spanish/French/Italian co-production which used a process called Hi-Fi Stereo 70. This process captured two anamorphic images, one for each eye, side by side on 65 mm film. A special lens on a 70 mm projector added polarization and merged the two images on the screen. The 1975 re-release of Warner Brothers' House of Wax, used a similar process without anamorphics called Stereovision. This format was developed by Allan Silliphant and Chris Condon, of Stereovision International Inc., who handled all technical and marketing aspects on a 5-year special-royalty basis with Warner Bros. The big screen 3D image was both bright and clear, with all the former sync and brightness problems of traditional dual 35 mm 3D eliminated. Still, it took many years more before IMAX began to test the water for big-screen 3D, and sold the concept to Hollywood executives.

IMAX 3D

Recently, Hollywood has released blockbusters shot in 35 mm as IMAX blow-up versions. Now many 3D films are being shown in the 70 mm IMAX format. The Polar Express in IMAX 3D 70 mm earned 14 times as much, per screen, as the simultaneous 2D 35 mm release of that film in the fall of 2004.

Blow-ups

Starting in the late 1950s and continuing until the mid-1990s, some 35 mm films were converted onto 70 mm prints for premiere showings in large cities or venues which could accommodate the format. This practice occurred for two reasons: The larger image area on each frame of 70 mm film allowed for clearer, brighter and steadier images, although it did not reduce film grain; and the six magnetic sound tracks available with 70 mm prints were vastly superior to the four-channel stereo sound tracks available on 35 mm prints (from 1953 to 1977, some 35 mm prints carried four-channel magnetic sound, and required special print stock with narrow perforations, type CS-1870). 70 mm prints were also used by a limited number of drive-in theaters because the larger frame area allowed use of higher intensity light to project a brighter image on their large screens. After the introduction of digital sound formats (DTS, SDDS, and Dolby Digital), 70 mm lost one of its major advantages over 35 mm film and thus usage of this expensive format declined markedly (A 70mm film print with magnetic sound is 10 to 15 times more expensive to make than a 35mm film print with optical digital sound.)

Technical specifications

Standard 65 mm (5/70) (Todd-AO, Super Panavision)

• spherical lenses
• 5 perforations/frame
• 42 frames/meter (12.8 frame/ft)
• 34.29 meters/minute (112.5 ft/minute)
• vertical pulldown
• 24 frames/second
• camera aperture: 52.48 by 23.01 mm (2.066 by 0.906 in)
• projection aperture: 48.56 by 20.73 mm (1.912 by 0.816 in)
• 305 m (1000 feet), about 9 minutes at 24 frame/s = 4.5 kg (10 pounds) in can
• aspect ratio: 2.2:1

Ultra Panavision 70 (MGM Camera 65)

Same as Standard 65mm except

• Shot with special anamorphic adapter in front of lens
• 1.25x squeeze factor, projected aspect ratio 2.76:1

Showscan

Same as Standard 65 mm except

• 60 frames per second

IMAX (15/70)

• spherical lenses
• 15 perforations per frame
• horizontal pulldown, from right to left (viewed from base side)
• 24 frames per second
• camera aperture: 70.41 by 52.63 mm (2.772 by 2.072 in)
• projection aperture: at least 2 mm (0.080 in) less than camera aperture on the vertical axis and at least 0.4 mm (0.016 in) less on the horizontal axis
• aspect ratio: 1.35:1 (camera), 1.43:1 (projected)

IMAX Dome (formerly: OMNIMAX)

Same as IMAX except

• special fisheye lenses
• lens optically centered 9 mm (0.37 in) above film horizontal center line
• projected elliptically on a dome screen, 20 degrees below and 110 degrees above perfectly centered viewers

Omnivision Cinema 180

Cinema 180, West Germany 1979

same as standard 65/70 except:

• photographed and projected with special fisheye lenses matched to large 180 degree dome screen
• Theatres upgraded from 70 mm 6track analog sound to DTS digital sound in 1995.

Omnivision started in Sarasota, Florida. Theatres were designed to compete with Omnimax but with much lower startup and operating costs. Most theatres were built in fabric domed structures designed by Siemens Corporation. The last known OmniVision Theatres to exist in USA are The Alaska Experience Theatre in Anchorage, Alaska, built in 1981 (closed in 2007, reopened in 2008), and the Hawaii Experience Theatre in Lahaina, Hawaii (closed in 2004). Canobie Lake Park in Salem, New Hampshire has a "Vertigo Theatre" that is a Cinema 180. A Cinema 180 is still operating at Rainbow's End (Theme Park)

One of the few producers of 70 mm films for Cinema 180 was the German company Cinevision (today AKPservices GmbH, Paderborn).

Dynavision (8/70)

• fisheye or spherical lenses, depending on if projecting for a dome or not
• vertical pulldown
• 24 or 30 frames per second
• camera aperture: 52.83 by 37.59 mm (2.080 by 1.480 in)

Astrovision (10/70)

• vertical pulldown
• normally printed from an Omnimax negative
• projected onto a dome
• almost exclusively in use only by Japanese planetariums
• the only 70 mm format without sound, hence the only one with perforations next to the edges

See also

• 70 mm Grandeur film
• Cine 160
• Cinerama
• Dolby Stereo 70 mm Six Track
• List of 70 mm films
• List of Early Wide Gauge Films
• List of film formats
• Ron Fricke
• Super Panavision 70
• Super Technirama 70
• Todd-AO
• Ultra Panavision 70

References

External links

• The American WideScreen Museum
• in70mm.com — The 70 mm Newsletter Devoted to 70 mm films new and old
• The History of the Todd-AO Projector