IMAX takes a different approach to immersion than Cinerama and other widescreen formats. IMAX has an aspect ratio of 1.43:1, which is barely wider than the Academy standard of 1.37:1. But IMAX is oriented horizontally on 70 mm film, so the area of the physical image is much greater than other formats. A larger physical image means higher resolution, allowing projection on a larger screen. It also allows the audience to sit closer to the screen. As a result, depending on where you're seated in the strongly raked auditorium, the screen fills much of the horizontal and vertical peripheral vision. The taller image also means that more of a scene can be captured above and below standard widescreen image of 2.2:1 or 1.85:1.

IMAX was introduced at EXPO 70 in Japan. For the first years of its life, it was installed largely in special venues like museums. Because of the size and weight of an IMAX film, films were limited to shorter features with travel, nature or science themes. Feature films started to include IMAX footage in 2010 with Walt Disney's Fantasia. However, it's difficult to film scenes with dialog with an IMAX film camera because the camera itself is noisy. Feature films like Transformers: Revenge of the Fallen and Mission: Impossible–Ghost Protocol are typically released with both IMAX and Panavision scenes.