http://en.wikipedia.org/wiki/IMAX
IMAXIMAX (for Image Maximum) is a film format created by IMAX Corporation that has the capacity to display images of far greater size and resolution than conventional film display systems. A standard IMAX screen is 22 m wide and 16 m high (72.6 x 52.8 ft), but can be larger. Currently, IMAX is the most widely-used system for large-format, special-venue film presentations. As of 2006, there were 280 IMAX theatres in 40 countries (60 percent of these are located in the U.S. and Canada).
A variation of IMAX, IMAX Dome (originally called OMNIMAX), is designed for projection on tilted dome screens. Films can also be projected in 3D with IMAX 3D.
Precursors
The desire to increase the visual impact of film has a long history. In 1929 Fox introduced Fox Grandeur, the first 70mm movie format, which quickly fell from use. Cinemascope and VistaVision widened the projected image from 35 mm film, and there were multi-projector systems such as Cinerama for even wider presentations. While impressive, Cinerama was cumbersome, difficult to set up and the joints between the screens were difficult to hide.
Technical aspectsThere is a 15 kW Xenon short-arc lamp used in IMAX projectors.
The intent of IMAX is to dramatically increase the resolution of the image by using much larger film stock at a resolution of about 10000 x 7000 pixels. To do this, 70 mm film stock is run "sideways" through the cameras. While traditional 70 mm film has an image area that is 48.5 mm wide and 22.1 mm tall (for Todd-AO), in IMAX the image is 69.6 mm wide and 48.5 mm 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 film through the projector was a difficult technical problem to solve; conventional 70 mm systems were not steady enough for the 586x 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 "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 4 registration pins engage the sprockets at the corners of the projected frame to ensure perfect alignment. Mr. 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. The largest 12-18 kW xenon arc lamps have hollow, water-cooled electrodes. An IMAX projector is therefore a substantial piece of equipment, weighing up to 1.8 tonnes and towering at roughly the size of a kitchen refrigerator. The xenon lamps are made of a thin layer of quartz crystal, and contain about 25 atmospheres of xenon gas; because of this, projectionists are required to wear protective body armour when changing or handling these lamps because the flying shards of crystal could be deadly when combined with the high pressure of the gas within.
IMAX uses a stronger "ESTAR" (Kodak's tradename 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 (esp. 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 sprockets per frame of 70 mm stock. The bulk of the film requires large platters rather than conventional film reels.
IMAX film does not include an embedded soundtrack in order to use more of the image area. Instead the IMAX system specifies a separate six-channel 35 mm magnetic tape synchronized to the film. (This original system--35 mm mag tape locked to a projector--was commonly used to "dub" or insert studio sound into the mixed soundtrack of conventional films.) By the early 90's, a separate digital 6-track source was synchronized using a more precise pulse-generator as a source for a conventional SMPTE timecode synchronization system. This development presaged conventional theatrical multichannel sound systems such as Dolby Digital and DTS. This digital source came in the form of a unit called a DDP (Digital Disc Playback) in which the soundtrack was recorded onto multiple CD-ROM discs which would play the sound which was recorded to the discs as a digital audio file. This DDP system has been replaced in almost all theaters with the newer DTAC (Digital Audio Theater Control) system which utilizes a computer running the IMAX's proprietary DTAC 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 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.
Further improvements and variations on IMAX include several 3-D presentation methods and the possibility of a faster 48 frames per second rate (known as IMAX HD, this system was tested in 1992 at the Canada Pavillion of the Seville Expo '92 with the film "Momentum," but was deemed too costly and abandoned but not before many theaters were retrofitted to project at 48 frames, especially Canada, in order to play the film "Momentum". A theme park in Germany also used IMAX HD for their theme park ride film in the mid 1990's.) Improvements in the sound systems have included a 3D sound system and the elliptical-pattern speaker-clusters.
IMAX theater 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 theaters seating runs 8 to 12 screen-heights) Also, the rows of seats are set at a steep angle (Up to 23 degrees in some domed theaters) so that the audience is facing the screen directly.
IMAX Dome/OMNIMAX
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-foot 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-foot-tall lamphouse on top. However, IMAX Corporation were quick to cooperate and were willing to redesign their 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. Leitz of Canada developed a fisheye lens that would project the image onto a dome instead of a flat screen.
The dome system, that the San Diego Hall of Science called OMNIMAX, uses a fisheye lens on the camera that squeezes a highly distorted 180 degree field of view onto the 70 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 degrees horizontally, 100 degrees above the horizon and 22 degrees 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. Many theaters continue to call it OMNIMAX.
OMNIMAX theaters are now in place at a number of major 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); 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 and Las Vegas hotels.
But despite their impressive capabilities and unique experience, the system seems likely to remain a novelty rather than a widespread commercial phenomenon. Relative to their size, OMNIMAX theaters are very expensive to build and maintain, and have a relatively small seating capacity. To make matters worse, only those seats closest to the center of the theater provide the full effect of the immersive view. Museums are able to run the theaters at a profit only because they are able to subrogate the construction expenses through grants and public fundraising and then show relatively inexpensive documentary films, often while still being able to keep admission prices lower than those of standard cinemas. In this way, OMNIMAX theaters have become a "cash cow" for financially strapped public institutions.
Another use of IMAX Dome technology is to provide an immersive visual experience to go with a ride simulator, as in Back to the Future: The Ride. Imax Dome was also used in the former EPCOT attraction, Horizons.
IMAX 3D
An IMAX 3D camera.To create the illusion of 3-dimensional depth, the IMAX 3D process uses two camera lenses to represent the left and right eyes. The two lenses are separated by an interoccular distance of about 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, we can be tricked into seeing a 3D image on a 2D screen. The IMAX 3D camera is very cumbersome, weighing over 113 kg/250 pounds. This makes it extremely difficult to film on-location documentaries. The IMAX screen, averaging at 8 stories tall, is the perfect medium for 3D movies to be shown on. Not only does the large negative format allow for pristine quality images, but the massive screen and close viewing distance provides a very immersive experience for the audience.
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 polarized perpendicular 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 synchronised 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.
One particular problem that 3D movies face is that the 3D effect does not extend past the boundaries of the physical screen. It is for this reason that the screen must be large enough to cover as much of the viewer's peripheral vision as possible. Another problem with IMAX 3D movies is due to an inherent difference between our eyes and the film format. Because of the large negative, depth of field is dramatically reduced, causing an often distracting depiction of the scene. Computer-generated imagery films do not have this problem as they are able to control the depth of field in the images to allow everything to be in focus. While some may argue that this is less artistic than regular 2D films that purposefully employ shallow depth of field for aesthetic reasons, the IMAX 3D experience is a much more immersive one than regular 2D films, and therefore the viewer can be disoriented by seeing images that are out of focus – a natural side-effect of the 3D experience.
Viewer experienceFor the viewer, these technical differences result in a much more immersive, engaging experience than conventional film projection. The large screen and close seating mean that much of the viewer's field of vision is filled with the image, and the high resolution and positional stability of the film format imparts a sense of reality and detail. IMAX film can be overwhelming at times, with some viewers experiencing motion sickness during scenes with significant motion, especially if the action cuts between moving and still scenes. In scenes where the motion on the screen moves downwards, a "free-fall" sensation is felt (like going down on a roller coaster).
HistoryThe IMAX system was developed by three Canadians: Graeme Ferguson, Roman Kroitor, and Robert Kerr. During Expo 67 in Montreal, In the Labyrinth, their multi-projector giant-screen system had a number of technical difficulties that led them to design a single-projector/single-camera system. 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, USA, a very large IMAX screen that measured 90 x 65 ft (27.3 x 19.7 m) 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 Space Theater and Science Center, opened in San Diego's Balboa Park in 1973. The first permanent IMAX 3D theatre was built in Vancouver, British Columbia, Canada for Transitions at Expo '86, and is still very much in use, as it is situated at the tip of Canada Place, a Vancouver landmark. As of Sep 2006, there were 280 IMAX theatres in 34 countries around the world. Half of these are commercial theaters and half are in educational venues.
Recent TroubleRecently, despite expanding its market with several new theaters (especially in Latin America and China), IMAX has continued to face financial difficulty. Over the summer of 2006 IMAX's stock fell markedly (by as much as 60%) with the announcement of legal trouble, falling again when the announced third quarter earnings were far behind the previous year's.
ContentAlthough IMAX is an impressive format from a technical perspective, its popularity as a motion picture format has traditionally been limited. The expense and logistics of producing and presenting IMAX films has dictated a shorter running time compared to conventional movies for most presentations (typically around 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. Although IMAX documentaries have been praised for their technical quality, critics have also complained that many have banal narration.
Some IMAX theaters had shown conventional films (using conventional projection equipment) as a sideline to the native-IMAX presentations. In the late 1990s there was a wave of interest in broadening the use of IMAX as an entertainment format. A few pure-entertainment IMAX short films have been created, notably T-Rex: Back to the Cretaceous, which had a successful run in 1998 and Haunted Castle, released in 2001 (both of these were IMAX 3-D films). In 1999, 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 2-D live-action native IMAX entertainment film, Young Black Stallion, in late 2003.
In the fall of 2002, IMAX and Universal Studios released a new IMAX-format of the 1995 theatrical film Apollo 13. This release marked the first use of the IMAX-proprietary "DMR" (Digital Re-mastering) process that allowed conventional films to be converted into IMAX format. Other theatrically-released films, including Star Wars Episode II: Attack of the Clones, would subsequently be re-released at IMAX venues using the DMR process. Because of a technical limitation on the size of the film reel, these early DMR releases were edited to conform to a two-hour length limitation. Later releases did not have this limitation. Current IMAX platters allow a run length of up to 150 minutes.
In 2003 a notable IMAX re-release, again using the DMR process, was The Matrix Reloaded. Later in 2003, the sequel The Matrix Revolutions was the first live action film to be released simultaneously in IMAX and conventional theaters, the first feature film being Treasure Planet.
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 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 aforementioned Matrix sequels and since 2004 has been releasing its Harry Potter film franchise in IMAX to strong financial success. In 2005 WB also released Batman Begins simultaneously in IMAX, which buoyed the film's strong legs helping it reach $200m at the domestic box office, and before the fourth Harry Potter film was released in IMAX format in November had claimed the record for most box office by a DMR movie. In summer 2006 WB released the highly anticipated Superman Returns remastered for IMAX and partially digitally transformed into 3D (director Bryan Singer chose four action scenes in the film to show in 3D. The film was a disappointment at the box office in light of its huge budget and perceived large fanbase, but the IMAX 3D release helped it to have strong staying power throughout the summer movie season. Most recently, WB released the animated film Happy Feet simultaneously in both conventional theatres and in IMAX 2D format. The studio has hinted that a future IMAX 3D release was still a possibility.
Noted feature film director James Cameron filmed a movie about the Titanic in 3D IMAX format, Ghosts of the Abyss.
Up to 2002, eight IMAX format films have received Academy Awards nomination with one win, the animated short, The Old Man and the Sea in 2000.
Many IMAX films have been remastered into HDTV format for the INHD channels.
IMAX as a music venue
In July 2005 the BFI IMAX Cinema in London became the first to host live music concerts. IMAX theater owners increasingly look to use the venue at varying times for alternatives to films.
Recently the London England IMAX has hosted a computer game festival using digital projectors on the large IMAX screen.
These uses have no particular relevance to IMAX as a product or a company.
Technical specifications
spherical lenses
70mm film, 15 perforations per frame
horizontal pulldown, from right to left (viewed from base side)
24 frames per second
camera aperture: 70.41 mm (2.772″) by 52.63 mm (2.072″)
projection aperture: at least 20.3 mm (0.80″) less than camera aperture on the vertical axis and at least 0.016″ less on the horizontal axis
aspect ratio: 1.43:1
IMAX Dome/OMNIMAX
Same as IMAX except:
special fisheye lenses
lens optically centered 9.4 mm (0.37″) above film horizontal center line
projected elliptically on a dome screen, 20 degrees below and 110 degrees above perfectly centered viewers
Notable IMAX venues include:
The Cinesphere at Ontario Place in Toronto, Ontario, Canada – the first permanent IMAX theatre.
The IMAX Theatre at Canada Place in Vancouver, British Columbia, Canada – the first permanent IMAX 3D theatre.
The IMAX/IMAX Dome at the Canadian Museum of Civilization in Gatineau, Quebec, Canada – the first dual IMAX/IMAX Dome installation.
Futuroscope, France – theme park, only place containing all versions of IMAX theatres. (Normal, Dome, 3D, 3D Dome ("Solido") and IMAX Magic Carpet.)
The Reuben H. Fleet Science Center in San Diego, California, USA – the first IMAX Dome installation.
IMAX in Belfast Odyssey Pavillion, Northern Ireland
IMAX, Sydney Australia, the largest of any IMAX or any other screeen in the world.
http://en.wikipedia.org/wiki/John_Berger
John Peter Berger (born November 5, 1926) is an art critic, novelist, painter, and author. The best-known among his many works include the novel G., winner of the 1972 Booker Prize, and the introductory essay on art criticism Ways of Seeing, written as an accompaniment to a significant BBC series of the same name, and often used as a college text.
Biography
Born in London, England, Berger attended St Edward's School in Oxford. "His father, S.J.D. Berger, O.B.E., M.C., had been an infantry officer on the western front during the First World War." Berger served in the British Army from 1944 to 1946; he then enrolled in the Chelsea School of Art and the Central School of Art in London. "Berger began his career as a painter and exhibited work at a number of London galleries in the late 1940s." "His art has been exhibited at the Wildenstein, Redfern and Leicester galleries in London. Berger has continued to paint throughout his career."
While teaching drawing (from 1948 to 1955), Berger became an art critic, publishing many essays and reviews in the New Statesman. His Marxist humanism and his strongly stated opinions on modern art made him a controversial figure from early in his career. He titled an early collection of essays Permanent Red, in part as a statement of political commitment, and later wrote that before the USSR achieved nuclear parity he had felt constrained not to criticize its policies; afterwards his attitude toward the Soviet state became considerably more critical.
In 1958 Berger published his first novel, A Painter of Our Time, which tells the story of the disappearance of Janos Lavin, a fictional exiled Hungarian painter, and his diary's discovery by an art critic friend called John. The book's political currency and detailed description of an artist's working process led to some readers mistaking it for a true story. After being available for a month, the work was withdrawn by the publisher, under pressure from the Congress for Cultural Freedom. The novels immediately succeeding A Painter of Our Time were The Foot of Clive and Corker's Freedom; both presented an urban English life of alienation and melancholy.
In 1962 Berger's distaste for life in Britain drove him into a voluntary exile in France.
In 1972 the BBC broadcast his television series Ways of Seeing and published its companion text, an introduction to the study of images. The work, in part, was derived from Walter Benjamin's essay The Work of Art in the Age of Mechanical Reproduction.
His novel G., a romantic picaresque set in the Europe of 1898, won the Booker Prize in 1972. When accepting the prize Berger made a point of donating half his cash award to the Black Panther Party in Britain, and retaining half to support his work on the study of migrant workers that became A Seventh Man, insisting on both as necessary parts of his political struggle.
Many of his texts, from sociological studies to fiction and poetry, deal with experience.
Berger's sociological writings include A Fortunate Man: The Story of a Country Doctor (1967) and A Seventh Man: Migrant Workers in Europe (1975). His research for A Seventh Man led to an interest in the world which migrant workers had left behind: isolated rural communities. It was his work on this theme that led him to settle in Quincy, a small village in the Haute-Savoie, where he has lived and farmed since the mid-1970s. Berger and photographer Jean Mohr, his frequent collaborator, seek to document and to understand intimately the lived experiences of their peasant subjects. Their subsequent book Another Way of Telling discusses and illustrates their documentary technique and treats the theory of photography both through Berger's essays and Mohr's photographs.
His studies of single artists include most prominently The Success and Failure of Picasso (1965), a survey of the modernist's career; and Art and Revolution: Ernst Neizvestny, Endurance, and the Role of the Artist, on the Soviet dissident sculptor's aesthetic and political contributions.
In the 1970s Berger collaborated with the Swiss director Alain Tanner on several films; he wrote or co-wrote Salamandre, Jonah who will be 25 in the year 2000, and Messidor.
His major fictional work of the 1980s, the trilogy Into Their Labours (made up of the novels Pig Earth, Once in Europa, and Lilac and Flag), treats the European peasant experience from its farming roots into contemporary economic and political displacement and urban poverty. Many of Berger's essays as well draw on his rural neighbors.
In recent essays Berger has written of photography, art, politics, and memory; he has published in The Shape of a Pocket a correspondence with Subcomandante Marcos, and written short stories appearing in venues like the Threepenny Review and The New Yorker. His sole volume of poetry is Pages of the Wound, though other volumes such as the dense theoretical essay And Our Faces, My Heart, Brief as Photos contain poetry as well as prose.
Berger's recent novels include To the Wedding, a love story dealing with the AIDS crisis that stems from his own familial experience, and King: A Street Story, a novel on homeless and shantytown life told from the perspective of a street dog. Berger initially insisted that his name be kept off the cover and title page of King, wanting the novel to be received on its own merits.
His essays and criticism are available in many different volumes, including About Looking, Photocopies, The Shape of a Pocket, The Sense of Sight, and Keeping a Rendezvous. The 2001 Selected Essays contains selections from many of these; otherwise, their contents are distinct.
