Production Glossary
IMAX
IMAX was created by Robert Kerr, Graeme Ferguson, William C. Shaw, and Roman Kroitor. This motion picture filming process is owned under the IMAX Corporation, a company in Canada. IMAX is capable of shooting and projecting images in larger scale and better resolution than traditional filming formats.The Technology of IMAX
In order to increase the picture resolution, IMAX utilizes a bigger film frame. Ordinary cameras scroll 65 mm film stock vertically through the camera, but IMAX passes its film through horizontally. By doing so, IMAX cameras can transport 3x as many feet of film through the camera per second so that it parallels the established film speed of 24 frames per second.
Because of IMAX’s bulky film size, a platter as opposed to film reel is necessary for operation. These platters vary in size from 3.9 to 6 feet in diameter. They generally hold 1 to 2.75 hours of film. The format name for IMAX films is “15/70”, referencing the 15 sprocket holes for every frame of film.
To utilize its film area, a six-channel, 35 mm magnetic film of soundtrack is matched to the film instead of embedding a soundtrack into the film itself. After a number of revisions, IMAX settled on a six-track source that is attached to the projector with a SMPTE, a time code synchronization system. This system changes the audio file directly to analogue and ensures that the sound remains in sync with the film. To achieve a three-dimensional effect, IMAX theaters install speakers all around the theater and immediately behind the screen.
The IMAX Corporation offers four model of projectors to display their films. Each of these projectors us the “15/70” format. They are MPX (for retrofitted theaters), GT- Grand Theater, SR- Small Rotor, and GT 3D-dual rotor. These projectors are equipped with the proper tools to pull the bigger film through. William Shaw, one of the creators of IMAX, adapted the “rolling loop”. The unit uses a “puffer” of compressed air to speed the film up while a vacuum draws the film onto the lens. Then, a field flattener presses it onto the image field.
IMAX films are shown in specially crafted theaters to give the audience the maximum viewing experience. Seating it positioned one screen height away from the screen (traditional theaters start seating eight to twelve screen heights away). While some theaters are normal in shape (typically square or rectangular), many early IMAX theaters were dome-shaped. This shape of theater utilized the fish-eye lens that most IMAX films shoot with more effectively than a flat screen.
IMAX is known for using 3D and HD processes to enhance the viewing experience. 3D filming requires that a separate cameras lens shoots for the left eye and then the right, spaced out at the average distance between humans eyes. The audience member wears a pair of glasses in which each lens is crafted to view the film as the two rolls are played at the same time, creating a 3D effect. Despite the quality of IMAX HD, the production is three to five times more expensive because each reel of film has a duration of half the original reel. This issue makes IMAX HD the least utilized feature in the franchise.
In order to view formerly released movies in IMAX, it must be remastered using DMR (Digital Media Remastering). This upgrade from regular film to IMAX is easier to accomplish than filming an entire full-length motion picture in the IMAX format. The heavy, louder cameras have hindered filmmakers from completing that task. However, IMAX has found great success with documentaries about history and science. IMAX cameras have captured images from space, atop the highest mountains in the world, and down in the deepest parts of the Atlantic ocean. IMAX theaters are a part of museums and theme parks that teach visitors about science and the world around them.
