Every way you look at it, IMAX is big. The diagram above compares the IMAX filmstrip (shown below) to 'normal' 70mm and 35mm.

People are entranced with the big picture. In the early 1800s, Robert Fulton amazed audiences with his Cyclorama, a 16-metre high by 130-metre long painting that ran on rollers. The Lumiere brothers, not content with their pioneering 35mm film efforts, even managed to screen movies shot on 75mm film.

The 3-strip 65mm Cinerama process emerged in 1963, quickly followed by CinemaScope, VistaVision, Circa-rama, Technirama, Todd-AO and so on. Then came IMAX, a process that side-stepped the perception that audiences just wanted a big, wide picture.

Instead, the Canadian developers of the IMAX process headed for a screen picture that was just huge... very enveloping, very sharp and almost grainless, swamping the eye's peripheral vision; the field of vision is 50° vertical and 130° horizontal.

The IMAX camera uses 65mm negative film (from which 70mm projection prints are made). An IMAX film frame measures 48.5mm high by 69.6mm wide - a total area of 3375.6mm2, over 10 times the frame area of conventional 35mm film.

Each IMAX film frame has fifteen perforations; a single frame races past the camera's aperture in 6 milliseconds; each second, 1.7m of film rips past; each minute exposes an expensive 102.6 metres of Mr Kodak's famous product.