70mm

70mm is the largest standard exhibition film gauge.

aspect ratios
Magnetic sound and noise reduction
DTS discs

Instructions on proper demagnetizing/degaussing of equipment.

handling of mag prints/degaussing

IMAX

IMAX is a 70mm film format on which the image is printed horizontally, resulting in a much larger filmed image than conventional 70mm. It's often referred to as 15/70, 15 being the number of perforations in a single frame.

A frame of IMAX film.

5 perf 70mm

Resources

Images of Various Aspect Ratios and Sound Formats, 5/70mm

Frames from a 70mm print of Aliens. Blow-up from 35mm, aspect ratio 1.85:1, magnetic audio track.
Frames from a 70mm print of It's a Mad, Mad, Mad, Mad World. Aspect ratio is 2.76:1 (Ultra Panavision) with a DTS audio track.
Frames from a 70mm print of 2001:A Space Odyssey. Aspect ratio 2.2:1 with magnetic audio track
Alignment chart from a 70mm print of Inherent Vice. Blow-up from 35mm, aspect ratio 1.85:1
Inspecting a 70mm print of West Side Story. Aspect ratio 2.2:1, DTS audio track
Boston Light and Sound 5/70 test film on screen