How cinema is captured and presented through the IMAX format Premium

IMAX film format revolutionises cinema with immersive experience, high resolution, and large screens despite drawbacks

Cinema has always been a home to spectacle. Most theatrically released cinematic works, especially till the development of digital photography, employed the use of 35 mm film stock to capture the stunning vistas and cinematic protagonists. For the bulk of its history, almost all movies were shot using this 35mm film. Most modern cinematic productions have since replaced the 35mm film stock with a digital sensor. But film purists argue that film stock provides for superior resolution.

Standard film stock is a photochemical emulsion with a total width of 35mm, which records images passing vertically through a camera. Some of that frame width needs to be used to accommodate sprocket holes, which are called perforations (or perfs, if you will), that pass the film through the camera. A standard 35mm film stock has four perforations. As must be self evident, a larger surface area on a piece of film would allow for more photographic information to be captured. This was made possible through the use of 70mm film stock. The expansive imagery of the American West in Raoul Walsh’s 1930 film The Big Trail was brought to light through the use of 70mm film. But it wasn’t until television started stealing viewers away from Hollywood in the 1950s that the industry recognised the benefit of making 70mm a major event.

This period led to the release of epics such as Lawrence of Arabia and The Sound of Music in the 1960s. The numbers bore out the impact that the 70mm format had with its visual resolution and superior sound quality.

It was in this period that Graeme Ferguson, Roman Kroitor, Robert Kerr, and William C. Shaw came together to develop what would become IMAX.

IMAX is a motion picture film format. It consists of a production pipeline of high-resolution cameras, film formats, projectors, and theatres. Developed in Canada in the 1970s, IMAX seeks to give the viewer an immersive movie-watching experience with its large screens. IMAX theatre screens have a tall aspect ratio of 1.43:1, meaning that the width of the screen is 1.9 times the height of the screen. The screens can be 18 by 24 metres in size, with the largest screen in Leonberg, Germany, measuring 38.8 metres by 21 metres.

The IMAX negative frame has a size of 70x48mm, nearly eight times the size of what a traditional cinema film stock can capture. The IMAX format uses 70 mm film run horizontally through the projector. In normal film projection theatres, a 35 mm or a 70 mm film is run vertically. Because of this horizontal orientation, the IMAX format produces images that can be screened at 8.3 times the size as a regular 35 mm film or 3.4 times as large as the regular 70 mm film. The larger the surface area of a piece of film, the more photographic information it will contain. This means that an IMAX image yields more detail in the image.

IMAX cameras are notably larger and bulkier compared to standard cinema cameras. This size is primarily due to the large film format they use. This larger film size allows for higher resolution and clarity. Digital IMAX cameras, while smaller than their film counterparts, are still larger than most standard digital cinema cameras due to their advanced sensors and technology. The IMAX film format provides an extremely high resolution vis-à-vis its 35mm counterpart. In fact, theoreticians estimate that a standard 35mm film would have a digital resolution of around 4k, whereas a standard 70mm film would resolve at around 8k. In comparison, the IMAX format is estimated at having an equivalent digital resolution of 18k.