Camera[edit]

An IMAX camera inside a display case at the National Media Museum, Bradford, UK.
IMAX increases the resolution of the image by using a much larger film frame: while a frame of 35mm film offers approximately six thousand lines (6K) of horizontal resolution, an IMAX negative can potentially display the equivalent of 18 thousand lines (18K) of horizontal resolution.[9] To achieve this,65 mm film stock passes horizontally through the camera, 15 perforations at a time resulting in a speed of 102.7 metres per minute. Traditional 65 mm cameras pass film vertically through the camera five perforations at a time resulting in a speed of 34 metres per minute. In comparison, 35 mm film runs vertically through the camera four perforations at a time, resulting in a speed of 27.4 metres per minute.
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Image area of 65 mm film is 48.5 mm 22.1 mm (1.91 in 0.87 in) (for Todd-AO), in IMAX the image is 69.6 mm 48.5 mm (2.74 in 1.91 in) tall. In order to match standard film speed of 24 frames per second, three times the length of film moves through the camera.
Film[edit]
The IMAX format is generically called "15/70" film, the name referring to the 15 sprocket holes or perforations per frame. The film's bulk requires horizontal platters, rather than conventional film reels.[11] IMAX platters range from 1.2 to 1.83 meters (3.9 to 6.0 ft) diameter to accommodate 1 to 2.75 hours of film. Platters with a 2.5 hour feature film weigh 250 kilograms (550 lb).
IMAX uses ESTAR-based print film[12] in their 15/70 rolling-loop film projection systems. ESTAR-based print film provides greater precision. The chemical development process does not change the size or shape of ESTAR print film, and IMAX's pin registration system
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