IMAX is a proprietary system of high-resolution cameras, film formats, film projectors, and theaters originally known for having very large screens with a tall aspect ratio (about 1.43:1) and steep stadium seating. More recently the aspect ratio has mostly become 1.90:1 (slightly wider than the 35 mm American and British widescreen standard for theatrical film of 1.85:1), with the 1.43:1 ratio format being available only in selected locations.
Graeme Ferguson, Roman Kroitor, Robert Kerr, and William C. Shaw were the co-founders of what would be named the IMAX Corporation (founded in September 1967 as Multiscreen Corporation, Ltd.), and they developed the first IMAX theatre projection standards in the late 1960s and early 1970s in Canada.