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Since IMAX® film is extremely large, it is not surprising that the camera is oversized and heavy, weighing 38 kg (84 lbs.). Lightweight portable cameras are used for special applications, but the regular camera is the workhorse of the film crew. Sturdy tripods, cranes, dolly tracks and pure muscle are required to manoeuvre it into position. Special mounts on helicopters and small planes hold the camera steady for those exciting aerial shots audiences have come to expect in an IMAX film.
Since a frame of IMAX film holds an image 10 times larger than that of a 35 mm film, a film magazine is good for a mere three minutes of recording. The usual camera speed of 24 frames per second is sometimes increased to 48 or 96 FPS, which really limits the time a film magazine can be used. For this reason, the IMAX camera is reloaded often during the filming of lengthy sequences.
The IMAX projector is the most powerful projector ever built and has the highest resolution. Its lamp is so bright that it would be possible to see it from the moon.
Both IMAX and IMAX dome (formerly known as OMNIMAX®) films use a "15 perf 70"* format. The only difference between them lies in the size of the screen. Regular IMAX films are projected onto a flat vertical screen that is approximately six to seven storeys high, whereas dome films are projected onto a tilted dome screen with a diameter of 24 metres.
In an IMAX theatre, the stairs are steeply raked, so each seat is as close to the screen as possible, giving the audience an unobstructed view.
* "15 perf 70" means that there are 15 perforations per picture frame on a 70 mm film.
