IMAX 70mm is presented as the highest-specification cinema format, offering a much larger 1.43:1 image, exceptional brightness and detail on enormous screens. It matters because films such as Christopher Nolan’s The Odyssey are available both in IMAX 70mm and digital IMAX, but the film version can deliver a more immersive experience where the right theatre is available.

IMAX 70mm uses 15/70 film frames measuring 69.8 by 48.5mm and can provide an estimated 18K-equivalent level of detail, projected onto screens up to 59 by 79 feet. It is rare and costly: there are about 24 compatible theatres in the US, nine in Canada and six elsewhere, while each print reportedly costs about $80,000. Digital IMAX with Laser is more widely available and still better than typical 2K cinema projection, but is limited to 4K and often cannot show the taller 1.43:1 image.