The history of large format films started with experiments made by various Hollywood studios in the 1950s as they looked for features that would set films apart from television. Parts of the film "Oklahoma!" were filmed in a 65mm film format in 1954 (source: DP70.com). The 1967 EXPO in Montreal, Canada was the start of the IMAX Corporation. The founders of IMAX filed patents on their 15/70mm format (15 perforations along a 70mm image). The field was theirs for the next 20 years but adoption was slow. When the IMAX patents expired in the early 1990s companies like World Odyssey and Cinema Development Company were able to supply theaters with the 15/70 large format film system.