IMAX is the brand name for a 70mm film format, with 15 perforations per frame (15/70), and its corresponding camera, projection, sound and theatre-design systems. Since the format’s debut in 1970, the IMAX Corporation has established an extensive filmography and a global theatre network. While digital camera and projection systems are now ubiquitous across the movie industry, 15/70 film remains in limited use for film production, and is still exhibited at a small selection of cinemas.

IMAX emerged from converging trends in late-1960s experimental filmmaking, specifically from some custom-format films created for World’s Fairs. At Expo 67, in Montreal, Quebec, Canada, two pavilions featuring immersive multi-image projection and unconventional theatre design provided the technical and artistic foundation for what would evolve to become IMAX. The Labyrinth Pavillion presented a specially made experimental film In the Labyrinth (Dans le labyrinthe), directed by Roman Kroitor, Colin Low and Hugh O’Connor from the National Film Board of Canada – the exhibit had its visitors walk through a series of chambers featuring unconventional configurations of 70mm and 35mm projections. The ‘Man the Explorer’ Pavillion presented Polar Life, directed by Graeme Ferguson and edited by Toni Myers, which offered a multiple-projector, eleven-screen panorama to an audience seated on a rotating platform (CINEMAexpo67, 2017). Planners for the upcoming Expo ’70 in Osaka, Japan, were impressed by the creativity and popularity of these projects and invited their creators to produce a new immersive experience for their planned Fuji pavilion. To take on this project, Ferguson, Kroitor, engineer William Shaw and business partner Robert Kerr formed the Multiscreen Corporation (later renamed IMAX Corp.) and, along with Low (as art director) and director Donald Brittain, grasped the opportunity to not only expand on their existing body of work in experimental documentary, but also to create a new form of film technology to match their artistic vision. The result was the first IMAX film, Tiger Child (1970), where the audience stood on a turntable as they viewed the first 15/70 film projection. This primarily consisted of multi-image compositions shot on regular 70mm and 35mm, with a few full-screen shots captured with a prototype IMAX camera (Feldman, 2014: p. 159).

Expos continued to be central to IMAX’s technical development with successive new systems – including IMAX 3D, Solido, Magic Carpet and IMAX HD – debuting at World’s Fairs throughout the 1980s and 1990s. These events offered large novelty-seeking audiences, generous funding for projects highlighting technical innovation and a rare opportunity for architectural experimentation in theatre design, given the temporary nature of most pavilions. These unique circumstances allowed IMAX’s filmmakers and engineers to experiment with the shape and size of screens, sound-system configurations, seating and audience flow, and technically complex projection systems, in ways that had, historically, been inaccessible to experimental filmmakers. 

The World’s first permanent IMAX theatre was opened in 1971 at the Ontario Place Cinesphere in Toronto, Canada. The Cinesphere established the unique geometric properties of subsequent IMAX theatres, with a steeply raked floor, a screen not only wide but also unusually tall, plus the precise directional effects of a six-channel sound system. These features emerged from their inventors’ Expo-based explorations in generating a novel relationship between the audience and the screen, while also prioritizing sensory engagement. The largest-ever IMAX screen, and indeed the largest screen in cinema’s history (demolished in 2016), was constructed in Sydney, Australia, and was 35.7m (117.13 ft) wide and 29.7m (97.44 ft) high. While some filmmakers have used multi-image techniques in IMAX films, particularly when incorporating footage shot in other formats, the refinement of the 15/70 camera system, alongside the sensory possibilities of the unique theatre geometry, ensured that immersive imagery would become an aesthetic priority in the IMAX filmography, and the foundation stone of the format’s brand identity. 

During the period from 1971 to 2000, the vast majority of IMAX cinemas were constructed within museums and science centers, as well as at tourist attractions with an educational focus. Consequently, IMAX was initially developed as a documentary medium, which necessarily had an impact on both IMAX filmmaking practice and its technological development. A striking example of this institutional influence is seen with the Smithsonian’s National Air and Space Museum in Washington, DC, whose IMAX cinema has not only sponsored the production of many films about aviation – thereby encouraging advances in aerial IMAX cinematography – but also facilitated collaboration between IMAX and NASA towards the design of IMAX cameras for use in space, the training of astronauts in cinematography, and the documenting of the Space Shuttle program. While this institutional/educational support of IMAX filmmaking came with certain creative restrictions – particularly with regard to dramatic narrative – it did greatly improve the format’s economic viability, since each IMAX film would typically have a far longer run than a standard theatrical release. 

In 1994, IMAX was acquired by WGIM Acquisition Corporation, initiating a shift toward commercial filmmaking. Projector systems for multiplexes (IMAX SR and MPX) and a digital remastering system (DMR) for reformatting 35mm feature films were developed. The first DMR IMAX release, in 2002, was a transformed version of Ron Howard’s Apollo 13, whose subject matter made it appropriate for screening at both commercial venues and science museums. Since then, not only have IMAX versions of mainstream films become more commonplace, but IMAX 15/70 production technology has been embraced by dramatic filmmakers. These films typically have variable aspect ratios, with full-frame IMAX sequences alongside those shot in other formats (35mm, 70mm and various digital formats). Notable among these filmmakers is Christopher Nolan, who consistently shoots on IMAX film and prioritizes film (over digital) exhibition.