IMAX is a motion picture film format and projection standard created by the Canadian IMAX Corporation. The Company’s activities include the design, leasing, marketing, maintenance and operation of IMAX film and digital theatre systems as well as the development, production, post production and distribution of IMAX motion pictures.
IMAX has the capacity to record and display images of far greater size and resolution than most conventional film systems. A standard IMAX screen is 22 m × 16.1 m (72 ft × 53 ft), but can vary. IMAX theatres are described as either "Classic Design," (Purpose-built structures designed to house an IMAX theatre) or "Multiplex Design." (Existing multiplex auditoriums that have been retrofitted with IMAX technology). IMAX screens in classic design locations range in size from 51’ x 37’ to 117’ x 96’ whereas IMAX screens in multiplex design locations range in size from 47’ x 24’ to 74’ x 46’. The world's largest cinema screen (and IMAX screen) is in the LG IMAX theatre in Sydney, New South Wales. It is approximately 8 stories high, with dimensions of 35.73 m × 29.42 m (117.2 ft × 96.5 ft) and covers an area of more than 1,015 m2 (10,930 sq ft).
IMAX is the most widely used system for special-venue film presentations. As of December 2009, there were more than 400 IMAX theatres in over 40 countries. Imax Corporation has released four projector types that use its 15-perforation, 70mm film format: GT (Grand Theatre), GT 3D (dual rotor), SR (Small Rotor), and MPX, which was designed to be retrofitted in existing multiplex theatres. In July 2008, the company introduced a digital projection system, which it has not given a distinct name or brand, designed for multiplex theatres with screens no wider than 21.3 m (70 ft).
All IMAX projectors, except the standard GT system, can project 3D images.
Most IMAX theatres have flat, rectangular screens, but IMAX Dome theateres, formerly branded as OMNIMAX, use a GT projector with a fish-eye lens to project an image on a tilted hemispheric dome screen. Imax also has a special technique in which places the viewer in the movie, using seat movement/vibration at specific points in the film.
The desire to increase the visual impact of film has a long history. In 1929, Fox introduced Fox Grandeur, the first 70 mm movie format, but it quickly fell from use. In the 1950s, CinemaScope (introduced in 1953) and VistaVision (1954) widened the image projected from 35 mm film, and there were multi-projector systems such as Cinerama (1952) for even wider presentations. While impressive, Cinerama was difficult to set up, and the seams between adjacent projected images were difficult to hide.
During Expo 67 in Montreal, Kroitor's In the Labyrinth and Ferguson's Man and the Polar Regions both used multi-projector, multi-screen systems. Each encountered a number of technical difficulties that led them to found a company, initially called "Multiscreen", with a primary goal of designing and developing a simpler approach. The single-projector/single-camera system they eventually settled upon was designed and built by Shaw, based upon a novel "Rolling Loop" film-transport technology purchased from the Australian inventor Ronald Jones. Later, when it became clear that a single, large-screen image had far more impact than multiple smaller ones, Multiscreen changed its name to IMAX.
Tiger Child, the first IMAX film, was demonstrated at Expo '70 in Osaka, Japan. The first permanent IMAX system was set up in Toronto at Ontario Place in 1971, and is still in operation. During Expo '74 in Spokane, Washington, a very large IMAX screen that measured 90 m × 65 m (300 ft × 210 ft) was featured in the US Pavilion (the largest structure in the expo). About 5 million visitors viewed the screen, which covered a person's total field of vision when looking directly forward. This easily created a sensation of motion for nearly everyone, and motion sickness in a few viewers. However, it was only a temporary screen for the six-month duration of the Expo. Several years later, a standard size IMAX screen was installed, and is still in operation at the renamed "Riverfront Park IMAX Theatre."
The first permanent IMAX Dome installation, the Reuben H. Fleet Science Center, opened in San Diego's Balboa Park in 1973. The first permanent IMAX 3D theatre was built in Vancouver, British Columbia for Transitions at Expo '86, and was in use until 30 September 2009. It was located at the tip of Canada Place, a Vancouver landmark.
The intent of IMAX is to dramatically increase the resolution of the image by using a much larger film frame. To achieve this, 65 mm film stock is run horizontally through the cameras. While traditional 65 mm film has an image area that is 48.5 mm × 22.1 mm (1.91 in × 0.87 in) (for Todd-AO), in IMAX the image is 69.6 mm × 48.5 mm (2.74 in × 1.91 in) tall. In order to expose at standard film speed of 24 frames per second, three times as much film needs to move through the camera each second.
Drawing the large-format 70mm print film through the projector was a difficult technical problem to solve; conventional 70 mm systems were not steady enough for the 586× magnification. IMAX projection involved a number of innovations. William Shaw of IMAX adapted an Australian patent for film transport called the "rolling loop" by adding a compressed air "puffer" to accelerate the film, and put a cylindrical lens in the projector's "aperture block" for the film to be vacuumed up against during projection (called the "field flattener" because it served to flatten the image field), because the film actually touches the "field flattener" lens. The lens itself is twice the height of the film and is connected to a pneumatic piston so it can be moved up or down while the projector is running. This way, if a piece of dust comes off the film and sticks to the lens, the projectionist can switch to the clean side of the lens at the push of a button. The lens also has "wiper bars" made of a felt or brush-like material which can wipe the dust off the lens as it moves up or down to keep the show clean. IMAX projectors are pin stabilized, meaning four registration pins engage the perforations at the corners of the projected frame to ensure perfect alignment. Shaw added cam-controlled arms to decelerate each frame to eliminate the microscopic shaking as the frame "settled" onto the registration pins. The projector's shutter is also open for around 20% longer than in conventional equipment and the light source is brighter. An IMAX projector is therefore a substantial piece of equipment, weighing up to 1.8 t (2.0 short tons) and towering at over 178 cm (70 in) tall and 195 cm (77 in) long. The xenon short-arc lamps are made of a thin layer of fused quartz and contain xenon gas at a pressure of about 25 atmospheres (367 PSI); because of this, projectionists are required to wear protective body armor when changing or handling these in case the lamp breaks (e.g., due to a drop to the floor) because the flying quartz shards could be deadly when combined with the high pressure of the Xenon gas within.
IMAX uses a stronger "ESTAR" (Kodak's trade name for PET film) base. The reason is not for strength, but precision. Developing chemicals do not change the size or shape of Estar, and IMAX's pin registration (especially the cam mechanism) is intolerant of either sprocket-hole or film-thickness variations. The IMAX format is generically called "15/70" film, the name referring to the 15 sprocket holes per frame of 70 mm stock. The bulk of the film requires large platters rather than conventional film reels. IMAX platters range from 1.2m diameter to 1.83m diameter to accommodate 1 to 2.75 hrs of film. Platters with a 2.5 hour feature film will weigh 250kg.
In order to use more of the image area, IMAX film does not include an embedded soundtrack. Instead, the IMAX system specifies a separate six-channel 35 mm magnetic film synchronized to the film. (This original "mag-stripe" system was commonly used to "dub" or insert studio sound into the mixed soundtrack of conventional films.) By the early 1990s, a separate digital 6-track source was synchronized using a more precise pulse generator as a source for a conventional SMPTE time code synchronization system. This development presaged conventional software. The software works in a similar style as the DDP except that instead of the audio file being based on discs, it is instead played directly off a hard disk drive in the form of a single uncompressed audio file containing the 6 channels which are distributed directly to the amplifiers rather than using a decoding method such as Dolby Digital. Many IMAX theatres place speakers directly behind the screen, as well as distributing the speakers around the theatre to create a three-dimensional effect.
IMAX theatre construction also differs significantly from conventional theaters. The increased resolution allows the audience to be much closer to the screen; typically all rows are within one screen height. (Conventional theater seating runs 8 to 12 screen heights) Also, the rows of seats are set at a steep angle (up to 23° in some domed theatres) so that the audience is facing the screen directly.
In the late 1960s the San Diego Hall of Science (now known as the Reuben H. Fleet Science Center) began searching North America for a large-format film system to project on the dome of their planned 76 ft (23 m) tilted dome planetarium. One of the front-running formats was a double-frame 35 mm system, until they saw IMAX. The IMAX projector was unsuitable for use inside a dome because it had a 12 ft (3.7 m) tall lamp house on top. However, IMAX Corporation was quick to cooperate and was willing to redesign its system. IMAX designed an elevator to lift the projector to the center of the dome from the projection booth below. Spectra Physics designed a suitable lamphouse that took smaller lamps (about 18 inches long) and placed the bulb behind the lens instead of above the projector. In 1970, Ernst Leitz Canada, Ltd. (now ELCAN Optical Technologies) won a contract to develop and manufacture a fisheye lens projection system optimized to project an image onto a dome instead of a flat screen.
The dome system, which the San Diego Hall of Science called OMNIMAX, uses films shot with a camera equipped with a fisheye lens on the camera that squeezes a highly distorted 180° field of view onto the 65 mm IMAX film. The lens is aligned below the center of the frame and most of the bottom half of the circular field falls beyond the edge of the film. The part of the field that would fall below the edge of the dome is masked off. When filming, the camera is aimed upward at an angle that matches the tilt of the dome. When projected through a matching fisheye lens onto a dome, the original panoramic view is recreated. OMNIMAX wraps 180° horizontally, 100° above the horizon and 22° below the horizon for a viewer at the center of the dome. OMNIMAX premiered in 1973 at the Reuben H. Fleet Space Theater and Science Center showing two OMNIMAX features, Voyage to the Outer Planets (produced by Graphic Films) and Garden Isle (by Roger Tilton Films) on a double bill.
IMAX has since renamed the system IMAX Dome. However, some theaters may continue to call it OMNIMAX.
OMNIMAX theatres are now in place at a number of major North American museums, particularly those with a scientific focus, where the technical aspects of the system may be highlighted as part of the theme interest. The projection room is often windowed to allow public viewing and accompanied by informational placards like any exhibit. Inside the theatre, the screen may be a permanent fixture, such as at the St. Louis Science Center (which also plays a short educational video about the OMNIMAX system just before the feature film) and Boston's Museum of Science; or lowered and raised as needed, such as at the Science Museum of Minnesota (where it shares an auditorium with a standard IMAX screen). Before the feature begins, the screen is backlit to show the speakers and girders behind the screen. IMAX Dome screens may also be found at several major theme parks. While the majority of OMNIMAX theatres in museums focus on educational and documentary films, on special occasions, as with the release of Charlie and the Chocolate Factory at the Oregon Museum of Science and Industry, major studio releases are also shown. The largest IMAX Dome Theatres in North America are at Liberty Science Center in Jersey City, NJ and the Telus World of Science in Vancouver, BC, both of which have dome screens that are 88 feet in diameter.
To create the illusion of three-dimensional depth, the IMAX 3D process two camera lenses to represent the left and right eyes. The two lenses are separated by an interocular distance of 64 mm (2.5 in), the average distance between a human's eyes. By recording on two separate rolls of film for the left and right eyes, and then projecting them simultaneously, viewers experience seeing a 3D image on a 2D screen. The IMAX 3D camera is cumbersome, weighing over 113 kg (250 lb). This makes it difficult to film on-location documentaries.
There are two methods to creating the 3D illusion in the theatre. The first involves polarization. During projection, the left and right eye images are linearly polarized in opposite directions to one another as they are projected onto the IMAX screen. By wearing special eyeglasses with lenses polarized in their respective directions to match the projection, the left eye image can be viewed only by the left eye since the polarization of the left lens will cancel out that of the right eye projection, and the right eye image can be viewed only by the right eye since the polarization of the right lens will cancel out that of the left eye projection. Another method for 3D projection involves LCD shutter glasses. These glasses contain LCD panels which are synchronized to the projector which alternates rapidly at 96 frames per second between displaying the left and right images which are momentarily viewed by the appropriate eye by allowing that eye's panel to become transparent while the other remains opaque. While the panels within these active-shutter 3D glasses alternate at 96 frames per second, the actual film is displayed at 48 frames per second. IMAX also has a special technique in which places the viewer in the movie, using seat movement/vibration at specific points in the film.
Several films produced in the RealD 3D process for release in conventional theatres have also been presented in IMAX 3D, including Dreamworks' Monsters vs Aliens, Columbia Pictures' The Little Engine That Could, U2 3D and Avatar.
The IMAX HD system was tested in 1992 at the Canada Pavilion of the Seville Expo '92 with the film Momentum. It was deemed too costly and abandoned but not before many theatres were retrofitted to project at 48 frames, especially in Canada, in order to play Momentum. In the 1990's theme parks in Thailand, Germany, and Las Vegas used IMAX HD for their Motion Simulator rides. The Disney parks attraction Soarin' Over California features a modification of both IMAX HD and IMAX Dome, projecting in 48 frames per second.
The doubled IMAX HD frame rate means that each IMAX HD reel lasts half as long, and the logistical implications of this reach all the way up the film production chain. IMAX production by default is at least 3 to 5 times more expensive against common 35 mm production. The increased production costs make IMAX HD problematic regardless of overall production funding issues, and the format has not seen significant adoption.
A digital version of IMAX started rolling out in 2008. The new system is a projection standard only. Digital IMAX systems can show either 2D or 3D content in DCI or IMAX digital format (which in itself is a superset of DCI). The digital system alleviates the need for film reels and facilitates inexpensive distribution of IMAX features.
Despite those advantages, one big disadvantage is the resolution of the picture is much lower than the resolution of the normal IMAX film, which is estimated to be about 12000 × 8700 theoretical pixels or 6120 × 4500 actually discernible pixels. The screens used by IMAX multiplex locations range in size from 47' x 24' to 74' x 46' and those in classic IMAX locations range from 51' x 37' to 117' x 96', typically New South China Mall.  The digital installations have drawn some confusion based on poor consumer differentiation to the traditional 15/70 IMAX.
IMAX digital currently uses two 2K-resolution Christie projectors with Texas Instruments Digital Light Processing technology alongside parts of IMAX's proprietary technologies. The two 2K images are projected over each other, producing an image that is potentially of a slightly higher resolution than common 2K digital cinema. Originally, IMAX had been considering using two Sony 4K projectors. Some reviewers note that this approach may not produce image quality higher than using one 4K projector, which are available for some non-IMAX theaters, including AMC's own. 
Deals have already been signed with Hollywood studios for IMAX 3D features, such as Shrek Forever After 3D. IMAX recently signed a deal with AMC Theatres to start utilizing IMAX digital beginning July 2008 in the US. In December 2008 two digital screens were opened inside Odeon Cinemas in the UK and three inside Hoyts Cinemas in Australia with a fourth to follow later in 2009.
IMAX Corporation's decision not to designate the new digital installations in any manner has led to a backlash by some viewers who are disappointed to have paid a premium to view an IMAX presentation only to find it being shown with much lower resolution on a screen of relatively ordinary size. Some reviewers have pointed out that the visual artifacts due to low resolution are detrimental to the picture quality, especially for viewers seated closer to the screen. The company CEO has stated that in digital IMAX installations the first few rows of seats are removed, allowing the screen to be closer to moviegoers, which makes the screen appear larger than it would in a standard theater setting.
In early January 2010, IMAX announced that it was developing a 3D digital camera and expects its first prototype to be ready by early 2010 with the goal of an official launch in 2011.
Benefits of the IMAX 3D digital camera include proprietary, differentiated content for the IMAX theatre network; increased content for the Company's planned joint venture 3D TV Network; and lower production costs, due to the elimination of expensive film stock. 
On January 5 2010, IMAX announced it had entered into a joint venture partnership with Sony and Discovery Communications to develop the first 24/7 dedicated 3D television network in the U.S. Discovery, Sony, through its U.S. affiliate, Sony Corporation of America, and IMAX each will be equal partners in the joint venture. The new 3D network will feature content from genres that are most appealing in 3D, including natural history, space, exploration, adventure, engineering, science and technology, motion pictures and children's programming from Discovery, Sony Pictures Entertainment, IMAX and other third-party providers.
The use of the IMAX format has traditionally been limited to specialty applications. The expense and logistics of producing and presenting IMAX films has dictated a shorter running time compared to conventional movies for most presentations (typically shorter by about 40 minutes). The majority of films in this format tend to be documentaries ideally suited for institutional venues such as museums and science centers. IMAX cameras have been taken into space aboard the Space Shuttle, to Mount Everest, to the bottom of the Atlantic Ocean, and to the Antarctic to film such documentaries. An IMAX documentary about the success of the Mars Exploration Rovers was released in 2006, titled Roving Mars and used exclusive data from the Rovers. 
One of the first attempts at presenting an entertainment film in the IMAX format was The Rolling Stones: Live at the Max (1991), an 85-minute compilation of concert footage filmed in IMAX during the band's 1990 Steel Wheels tour, edited to give the impression of a single concert.
Later in the 1990s, there was increasing interest in broadening the use of IMAX as an entertainment format. More entertainment IMAX short films were created, notably T-Rex: Back to the Cretaceous (directed by Brett Leonard), which had a successful run in 1998 and Haunted Castle, released in 2001 (both of these were IMAX 3D films). In 1999, The Old Man and the Sea became the first fully-animated film to be released on IMAX screens and proceeded to win an Oscar. The same year, Disney produced Fantasia 2000, the first full-length animated feature released exclusively in the IMAX format (the film would later have a conventional theatrical release). Disney would also release the first 2D live action native IMAX entertainment film, Young Black Stallion, in late 2003. In 2008, the Rolling Stones concert film, Shine a Light, directed by Martin Scorsese, was released as an IMAX DMR blowup version.
In the fall of 2002, IMAX and Universal Studios released a new IMAX-format version of the 1995 theatrical film Apollo 13. This release marked the first use of the IMAX proprietary "DMR" (Digital Media Remastering) process that allowed conventional films to be upconverted into IMAX format. Other theatrically released films would subsequently be rereleased at IMAX venues in versions created using the DMR process. Because of a technical limitation on the size of the film reel, several early DMR releases were edited to conform to a two-hour maximum length. Later releases did not have this limitation; current IMAX platters allow a run length of up to 165 minutes. Some IMAX theatres have also shown conventional films (using conventional projection equipment) as a sideline to the native IMAX presentations.
Reviewers have generally praised the results of the DMR blowup process, which have superior visual and auditory impact to the same films projected in 35 mm. Many large format film industry professionals-like Frank Marshall (film producer)-point out, however, that DMR blowups are not comparable to films created directly in the 70 mm 15 perf IMAX format. They note that the decline of Cinerama coincided roughly with the supersession of the original process with a simplified, reduced cost, technically inferior version, and view DMR with alarm. IMAX originally reserved the phrase "the IMAX experience" for true 70 mm productions, but now allows its use on DMR productions as well. However, IMAX DMR versions of commercial Hollywood films are generally popular with audiences, with many people choosing to pay more than standard admission to see the IMAX version.
Since 2002 many other Hollywood films have been remastered for IMAX. Warner Brothers has especially embraced the format with the two Matrix sequels, and since 2004 has been releasing its Harry Potter film franchise in IMAX to strong financial success. Also in 2004 the company released the animated movie The Polar Express to IMAX in 3D. Express became the most successful movie ever to be released in IMAX theatres, making at least a quarter of the film total worldwide gross of $302 million from less than 100 IMAX screens; because of its success, it has been re-released each holiday season since. In 2005 WB also released Batman Begins simultaneously in conventional theatres and IMAX, helping the film it reach $200M at the domestic box office. In summer 2006 WB released the highly anticipated Superman Returns remastered for IMAX and partially digitally transformed into 3D (director Bryan Singer chose the only four action scenes in the film to show in 3D). Spider-Man 3 broke the IMAX gross record in 2007 by a huge margin.
The July 2008 Batman Begins sequel The Dark Knight featured six sequences (a total of 30 minutes) shot using IMAX technology, which the movie's press notes describe as the "first time ever that a major feature film has been even partially shot using IMAX cameras". The film broke box office records for IMAX, taking in about $6.3 million from 94 theaters in the U.S. and Canada over the opening weekend. The record for an IMAX opening weekend (as of May 2009) was set by Star Trek: The IMAX Experience, which took in $8.3 million. The current IMAX opening weekend record (as of December 2009) is held by Titanic director James Cameron's Avatar which brought in $9.5 million.
Many IMAX films have been remastered into HDTV format for the MOJO HD channel with limited commercial interruption. They can also occasionally be shown commercial free on HDNet and with limited commercials on HD Theater.
In 1996 IMAX was awarded the only Oscar given for Scientific and Technical Achievement by the Academy of Motion Picture Arts and Sciences. The award cites IMAX's innovations in creating and developing a method of filming and exhibiting large-format, wide-angle motion pictures.
In July 2005 the BFI IMAX Cinema in London became the first to host live music concerts, using a digital non-IMAX projector. IMAX theatre owners increasingly look to use the venue at varying times for alternatives to films.
The Science Museum London and BFI IMAX Cinema have also hosted computer game tournaments using digital projectors on the large IMAX screen. Other IMAX Theatres have also followed suit with game tournaments on their screens as well.
Same as IMAX except:
Cinepolis IMAX theatre at Galerias Shopping Mall in Guadalajara, Mexico
The black structure seen in this photo is the Luxor IMAX Theatre, situated in the Luxor Hotel
LG IMAX theatre at Darling Harbour, Sydney, Australia