1. IMAX
Authored by
M.SESHU KUMAR
Department of Computer Science & Engineering
S.V.V.S.N ENGINEERING COLLEGE
seshu_msk@yahoo.co.in
MOBILE:9848986844.
B. CHADRASEKHAR
Department of Computer Science & Engineering
S.V.V.S.N ENGINEERING COLLEGE
Email:Chandra.1674@gmail.com

2. Abstract During Expo 67 in Montreal, Canada, In the
Labyrinth, their multi-projector giant-screen system
IMAX (short for Image Maximum) is a film format had a number of technical difficulties that led them to
created by Canada's IMAX Corporation that has the design a single-projector/single-camera system.
capacity to display images of far greater size and Tiger Child, the first IMAX film, was demonstrated
resolution than conventional film display systems. A at Expo '70 in Osaka, Japan. The first permanent
standard IMAX screen is 22 m wide and 16.1 m high IMAX system was set up in Toronto at Ontario Place
(72.6 ft x 52.8 ft), but can be larger. Currently, in 1971, and is still in operation. During Expo '74 in
IMAX is the most widely-used system for large- Spokane, Washington, a very large IMAX screen that
format, special-venue film presentations. As of measured 90 x 65 ft (27.3 x 19.7 m) was featured in
March 2007, there were 280 IMAX theatres in 38 the US Pavilion (the largest structure in the expo).
countries (60% of these are located in Canada and the About 5 million visitors viewed the screen, which
United States). Half of these are commercial theatres covered a person's total field of vision when looking
and half are in educational venues. A variation of directly forward. This easily created a sensation of
IMAX, IMAX Dome (originally called motion for nearly everyone, and motion sickness in a
OMNIMAX), is designed for projection on tilted few viewers. However, it was only a temporary
dome screens. Films can also be projected in 3D with screen for the six-month duration of the Expo.
IMAX 3D. The Hyderabad, India IMAX has the Several years later, a standard size IMAX screen was
world's largest display screen. The biggest "IMAX installed, and is still in operation at the renamed
Dome" is in the Liberty Science Center in Jersey "Riverfront Park IMAX Theatre."
City, New Jersey. The world's largest IMAX 3D
cinema screen is located in Sydney, Australia. The first permanent IMAX Dome installation, the
Reuben H. Fleet Space Theater and Science Center,
Contents 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 is
• 1 Precursors still very much in use, as it is situated at the tip of
• 2 History Canada Place, a Vancouver landmark.
• 3 Technical aspects
• 4 IMAX Dome/OMNIMAX Over the summer of 2006, IMAX's stock fell
markedly (by as much as 60%) with the
• 5 IMAX 3D announcement of an SEC investigation[2], falling
• 6 IMAX HD again when the announced third quarter earnings
• 7 IMAX Digital 3D were behind the previous year's.
• 8 Content
• 9 Other Uses for IMAX Technical aspects
• 10 Technical specifications
• 11 IMAX venues
• 12 See also
A comparison between 35 mm and 15/70 mm
• 13 References negative areas
• 14 External links
Precursors
An IMAX camera inside a display case
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, which quickly fell
from use. In the 1950s, 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 difficult to set up,
and the joints between the screens were difficult to
hide.
History
The 15 kW Xenon short-arc lamp used in IMAX
The IMAX system was developed by four Canadians:
projectors
Graeme Ferguson, Roman Kroitor, Robert Kerr and
William C. Shaw. [1]

3. The intent of IMAX is to dramatically increase the projector--was commonly used to "dub" or insert
resolution of the image by using much larger film studio sound into the mixed soundtrack of
stock at a resolution comparable to about 10000 x conventional films.) By the early '90s, a separate
7000 pixels. To do this, 70 mm film stock is run digital 6-track source was synchronized using a more
"sideways" through the cameras. While traditional 70 precise pulse-generator as a source for a conventional
mm film has an image area that is 48.5 mm wide and SMPTE timecode synchronization system. This
22.1 mm tall (for Todd-AO), in IMAX the image is development presaged conventional theatrical
69.6 mm wide and 48.5 mm tall. In order to expose at multichannel sound systems such as Dolby Digital
standard film speed of 24 frames per second, three and Digital Theater System. This digital source came
times as much film needs to move through the in the form of a unit called a DDP (Digital Disc
camera each second. Playback) in which the soundtrack was recorded onto
multiple CD-ROM discs which would play the sound
Drawing the large-format film through the projector which was recorded to the discs as a digital audio
was a difficult technical problem to solve; file. This DDP system has been replaced in almost all
conventional 70 mm systems were not steady enough theaters with the newer DTAC (Digital Theater
for the 586x magnification. IMAX projection Audio Control) system which utilizes a computer
involved a number of innovations. William Shaw of running the IMAX's proprietary DTAC software. The
IMAX adapted an Australian patent for film transport software works in a similar style as the DDP except
called the "rolling loop" by adding a compressed-air that instead of the audio file being based on discs, it
"puffer" to accelerate the film, and put a cylindrical is instead played directly off a hard drive in the form
lens in the projector's "block" for the film to be of a single uncompressed audio file containing the 6
vacuumed up against during projection (called the channels which are distributed directly to the
"field flattener" because it served to flatten the image amplifiers rather than using a decoding method such
field). Because the film actually touches the "field as Dolby Digital.
flattener" lens, the lens itself is twice the height of the
film and is connected to a pneumatic piston so it can IMAX theater construction also differs significantly
be moved up or down while the projector is running. from conventional theaters. The increased resolution
This way, if a piece of dust comes off the film and allows the audience to be much closer to the screen;
sticks to the lens, the projectionist can switch to the typically all rows are within one screen-height.
clean side of the lens at the push of a button. The lens (Conventional theaters seating runs 8 to 12 screen-
also has "wiper bars" made of a felt or brush-like heights) Also, the rows of seats are set at a steep
material which can wipe the dust off the lens as it angle (Up to 23 degrees in some domed theaters) so
moves up or down to keep the show clean. IMAX that the audience is facing the screen directly.
projectors are pin-stabilized, meaning 4 registration
pins engage the sprockets at the corners of the IMAX Dome/OMNIMAX
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 The frame layout of the IMAX Dome film.
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 over 70"
[178 cm] tall and 75" [195 cm] long. The xenon
lamps are made of a thin layer of quartz crystal, and
contain xenon gas at a pressure of about 25
atmospheres; because of this, projectionists are
required to wear protective body armor 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. The Control room of an IMAX Dome Theatre.
IMAX uses a stronger "ESTAR" (Kodak's trade In the late 1960s the San Diego Hall of Science (now
name for PET film) base. The reason is not for known as the Reuben H. Fleet Science Center) began
strength, but precision. Developing chemicals do not searching North America for a large-format film
change the size or shape of Estar, and IMAX's pin- system to project on the dome of their planned 76-
registration (especially the cam mechanism) is foot tilted-dome planetarium. One of the front-
intolerant of either sprocket-hole or film-thickness running formats was a double-frame 35 mm system,
variations. The IMAX format is generically called until they saw IMAX. The IMAX projector was
"15/70" film, the name referring to the 15 sprockets unsuitable for use inside a dome because it had a 12-
per frame of 70 mm stock. The bulk of the film foot-tall lamp house on top. However, IMAX
requires large platters rather than conventional film Corporation was quick to cooperate and was willing
reels. to redesign its system. IMAX designed an elevator to
lift the projector to the center of the dome from the
In order to use more of the image area, IMAX film projection booth below. Spectra Physics designed a
does not include an embedded soundtrack. Instead suitable lamphouse that took smaller lamps (about 18
the IMAX system specifies a separate six-channel 35 inches long) and placed the bulb behind the lens
mm magnetic tape synchronized to the film. (This instead of above the projector. Leitz of Canada
original system--35 mm mag tape locked to a

4. developed a fisheye lens that would project the image become a "cash cow" for financially strapped public
onto a dome instead of a flat screen. institutions.
The dome system, which the San Diego Hall of Another use of IMAX Dome technology is to provide
Science called OMNIMAX, uses a fisheye lens on an immersive visual experience to go with a ride
the camera that squeezes a highly distorted 180 simulator, as in Back to the Future: The Ride. IMAX
degree field of view onto the 70 mm IMAX film. The Dome was also used in the former EPCOT attraction
lens is aligned below the center of the frame and Horizons and another Disney attraction, Soarin' Over
most of the bottom half of the circular field falls California. "Soarin'" Featured at Disney's California
beyond the edge of the film. The part of the field that Adventure and EPCOT.
would fall below the edge of the dome is masked-off.
When filming, the camera is aimed upward at an IMAX 3D
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.
IMAX 3D theatre in Eilat, Israel
OMNIMAX theaters are now in place at a number of
An IMAX 3D camera.
major American museums, particularly those with a
scientific focus, where the technical aspects of the
system may be highlighted as part of the theme To create the illusion of 3-dimensional depth, the
interest. The projection room is often windowed to IMAX 3D process uses two camera lenses to
allow public viewing and accompanied by represent the left and right eyes. The two lenses are
informational placards like any exhibit. Inside the separated by an interocular distance of about 64
theatre, the screen may be a permanent fixture, such mm/2.5 in., the average distance between a human's
as at the St. Louis Science Center (which also plays a eyes. By recording on two separate rolls of film for
short educational video about the OMNIMAX the left and right eyes, and then projecting them
system just before the feature film); or lowered and simultaneously, we can be tricked into seeing a 3D
raised as needed, such as at the Science Museum of image on a 2D screen. The IMAX 3D camera is very
Minnesota (where it shares an auditorium with a cumbersome, weighing over 113 kg/250 pounds. This
standard IMAX screen). Before the feature begins, makes it extremely difficult to film on-location
the screen is backlit to show the speakers and girders documentaries.
behind the screen. IMAX Dome screens may also be
found at several major theme parks. There are two methods to creating the 3D illusion in
the theatre. The first involves polarization. During
The OMNIMAX experience is quite different from projection, the left and right eye images are polarized
that of a regular IMAX theater. The image wraps perpendicular to one another as they are projected
around both sides of the viewer and upwards as well, onto the IMAX screen. By wearing special
which can give the impression one is actually inside eyeglasses with lenses polarized in their respective
the scene being projected. (A plain IMAX screen is directions to match the projection, the left eye image
large but does not create such a natural feeling of can be viewed only by the left eye since the
immersion because the viewer is aware that the scene polarization of the left lens will cancel out that of the
ends where the rectangular walls and ceiling begin.) 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
But despite their impressive capabilities and unique
projection. Another method for 3D projection
experience, the system seems likely to remain a
involves LCD shutter glasses. These glasses contain
novelty rather than a widespread commercial
LCD panels which are synchronised to the projector
phenomenon. Relative to their size, OMNIMAX
which alternates rapidly at 96 frames per second
theaters are very expensive to build and maintain,
between displaying the left and right images which
and have a relatively small seating capacity. To make
are momentarily viewed by the appropriate eye by
matters worse, only those seats closest to the center
allowing that eye's panel to become transparent while
of the theater provide the full effect of the immersive
the other remains opaque. While the panels within
view. Museums are able to run the theaters at a profit
these active-shutter 3D glasses alternate at 96 frames
only because they are able to subrogate the
per second, the actual film is displayed at 24 frames
construction expenses through grants and public
per second.
fundraising and then show relatively inexpensive
documentary films, often while still being able to
keep admission prices lower than those of standard One particular problem that 3D movies face is that
cinemas. In this way, OMNIMAX theaters have the 3D effect does not extend past the boundaries of
the physical screen. It is for this reason that the

5. screen must be large enough to cover as much of the been praised for their technical quality, critics have
viewer's peripheral vision as possible. Another also complained that many have banal narration. [citation
needed]
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 Some IMAX theaters had shown conventional films
dramatically reduced, causing an often distracting (using conventional projection equipment) as a
depiction of the scene. Computer-generated imagery sideline to the native-IMAX presentations. In the late
films do not have this problem as they are able to 1990s there was a wave of interest in broadening the
control the depth of field in the images to allow use of IMAX as an entertainment format. A few
everything to be in focus. While some may argue that pure-entertainment IMAX short films have been
this is less artistic than regular 2D films that created, notably T-Rex: Back to the Cretaceous
purposefully employ shallow depth of field for (directed by Brett Leonard), which had a successful
aesthetic reasons, IMAX screens take up more of the run in 1998 and Haunted Castle, released in 2001
viewer's vision than regular 2D films, and therefore (both of these were IMAX 3-D films). In 1999, The
the viewer can be disoriented by seeing images that Old Man and the Sea became the first fully-animated
are out of focus. The biggest 3D IMAX screen is in film to be released on IMAX screens and proceeded
Prasads IMAX located in Hyderabad, India.[3] to win an Oscar. The same year, Disney produced
Fantasia 2000, the first full-length animated feature
Improvements in the sound systems have included a released exclusively in the IMAX format (the film
3D sound system and the elliptical-pattern speaker- would later have a conventional-theatrical release).
clusters. Disney would also release the first 2-D live-action
native IMAX entertainment film, Young Black
IMAX HD Stallion, in late 2003.
Further improvements and variations on IMAX In the fall of 2002, IMAX and Universal Studios
include the possibility of a faster 48 frames per released a new IMAX-format of the 1995 theatrical
second rate, known as IMAX HD. This system was film Apollo 13. This release marked the first use of
tested in 1992 at the Canada Pavilion of the Seville the IMAX-proprietary "DMR" (Digital Re-
Expo '92 with the film Momentum, but was deemed mastering) process that allowed conventional films to
too costly and abandoned but not before many be "up" converted into IMAX format. Other
theaters were retrofitted to project at 48 frames, theatrically-released films, would subsequently be re-
especially in Canada.[citation needed] 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
A theme park in Germany also used IMAX HD for a conform to a two-hour length limitation. Later
film in the mid-1990s.[citation needed] Soarin' Over releases did not have this limitation. Current IMAX
California, originally built at Disney's California platters allow a run length of up to 150 minutes. It
Adventure before being replicated at Epcot, features was previously reported that Star Wars Episode III:
a modification of both IMAX HD and IMAX Dome, Revenge of the Sith was released with an IMAX
projecting in 48 frames per second. DMR version, however it never underwent the DMR
process. Venues that showed this film in an IMAX
IMAX Digital 3D screen used standard 35 mm projection.
A new IMAX projection system slated for use in In 2003 a notable IMAX re-release, again using the
mid-2008 simulates a 3D view and uses new digital DMR process, was The Matrix Reloaded. Later in
technology. This will alleviate the need for the use of 2003, the sequel The Matrix Revolutions was the first
bulky film reels and facilitate inexpensive live action film to be released simultaneously in
distribution of IMAX features. Deals have already IMAX and conventional theaters, the first feature
been signed with Hollywood studios for such film being Treasure Planet.
features, such as "Shrek Goes Forth 3D" [4]
Reviewers have generally praised the results of the
IMAX recently signed a deal with AMC to start DMR blowup process, which have superior visual
utilizing this new technology beginning July 2008[5]. and auditory impact to the same films projected in 35
mm. Many large format film industry professionals
Content 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
Although IMAX is an impressive format from a Cinerama coincided roughly with the supersession of
technical perspective, its popularity as a motion the original process with a simplified, reduced-cost,
picture format has traditionally been limited. The technically inferior version, and view DMR with
expense and logistics of producing and presenting alarm. IMAX originally reserved the phrase "the
IMAX films has dictated a shorter running time IMAX experience" for true 70 mm productions, but
compared to conventional movies for most now allows its use on DMR productions as well.
presentations (typically around 40 minutes). The However, IMAX DMR versions of commercial
majority of films in this format tend to be Hollywood films are generally popular with
documentaries ideally suited for institutional venues audiences, with many people choosing to pay more
such as museums and science centers. IMAX than standard admission to see the IMAX version.
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 Since 2002 many other Hollywood films have been
documentaries. Although IMAX documentaries have remastered for IMAX. Warner Brothers has

6. especially embraced the format with the • projected elliptically on a dome screen, 20
aforementioned Matrix sequels and since 2004 has degrees below and 110 degrees above
been releasing its Harry Potter film franchise in perfectly centered viewers
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
$200 m 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 IMAX venues
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). An
IMAX exclusive film about the enormous, surprising
success of the Mars Exploration Rovers was released
in 2006, titled Roving Mars and used exclusive data
from the Rovers. Spider-Man 3 broke the IMAX
gross record in 2007 by a huge margin.
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.
The black structure seen in this photo is the Luxor
Many IMAX films have been remastered into HDTV
IMAX Theater, situated in the Luxor Hotel.
format for the INHD channels.
Main article: List of IMAX venues
Other Uses for IMAX
In July 2005 the BFI IMAX Cinema in London
became the first to host live music concerts. IMAX
References
theater owners increasingly look to use the venue at
varying times for alternatives to films.
1. ^
http://ieee.ca/millennium/imax/imax_birth.html
The Science Museum London and BFI IMAX
2. ^ National Post Story "'Red Flags' at IMAX",
Cinema have also hosted computer game
Monday, April 09, 2007
tournaments using digital projectors on the large
3. ^ "Prasads, "Prasad's IMAX Multiplex Theater
IMAX screen. Other IMAX Theatres have also
- a review"
followed suit with game tournaments on their screens
4. ^
as well.
http://washington.bizjournals.com/baltimore/sto
ries/2007/12/03/daily35.html
Technical specifications 5. ^
http://biz.yahoo.com/ap/071207/imax_mover.ht
IMAX (15/70) ml?.v=2
• spherical lenses
• 70 mm 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: 1.34:1
IMAX Dome/OMNIMAX
Same as IMAX except:
• special fisheye lenses
• lens optically centered 9.4 mm (0.37″)
above film horizontal center line