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IMAX (short for Image Maximum) is a film format created by Canada's IMAX
Corporation that has the capacity to display images of far greater size and resolution than conventional film display systems available at the time. This technology was developed by four Canadians: Graeme Ferguson, Roman
Kroitor, Robert Kerr and William C. Shaw.
A standard IMAX screen is 22 m wide and 16.1 m high (72.6 ft x 52.8 ft), but can be larger. IMAX DOME (originally called OMNIMAX), is designed for projection on tilted dome screens.large-format, special-venue film presentations ar emainly done with IMAX. IMAX screen is close to a conventional 4:3 aspect ratio,
but is much bigger than that . the system power is typically 12500 W. four low-frequency loudspeakers in each cabinet with nested high- and mid-frequency horns are used for clarity and freedom from distortion.
screen
With IMAX the
projected image is 69.6 mm wide and 48.5 mm tall and three times as much film is required compared to conventional projection.
THE LENS
"rolling loop" film transport is used 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. The lens 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.
THE PROJECTOR
In IMAX projectors, 4 registration pins engage the sprockets
at the corners of the projected frame to ensure perfect alignment. cam-controlled
arms decelerate each frame to eliminate the microscopic shaking .The projector weighs up to 1.8 tonnes and height is over 70" and 75" long. The xenon lamps are made of a thin layer of quartz crystal, and contain xenon gas at a
pressure of about 25 atmospheres.
THE SOUND
IMAX film does not include an embedded soundtrack, but is included in a separate six-channel 35 mm magnetic tape
synchronized to the film. Many IMAX theaters place speakers directly behind the
screen as well as distributing the speakers around the theater to create a three-dimensional effect.
THE DOME
The dome system, 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
Full seminar report download:
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Sir ,
can you please mail me the presentation on Imax technology
my email id is ankur20072008[at]gmail.com