2K and 4K
Common digital-cinema raster classes. Two overlaid projectors do not add their horizontal pixel counts into one wider raster.
IMAX glossary
The shortest accurate definition of every technical term used on this site.
Film gauge, frame shape, projector, screen, and marketing program are different concepts. The glossary keeps them separate.
If a term still does not settle what a ticket buys, check the format comparison, venue record, and film record together.
Definitions
5/70
Conventional 70mm projection. The print runs vertically and advances five perforations per frame. It is not an IMAX projection system.
15/65
The camera-negative format for horizontal IMAX film. The stock is 65mm wide and advances fifteen perforations per frame.
15/70
The audience-facing IMAX film format. A 70mm release print runs horizontally and advances fifteen perforations per frame.
65mm
The negative stock normally used for large-format photography. Release prints are commonly 70mm wide.
70mm
The release-print width used by both conventional large-format projection and IMAX film. The perforation count and travel direction identify which one.
Anamorphic
An optical process that squeezes a wide scene onto a narrower film or sensor area, then expands it for viewing.
Aperture
The physical opening that defines the exposed or projected image area. Camera and projector apertures are related but not identical.
Aspect ratio
Picture width divided by picture height. At equal width, a smaller ratio produces a taller image.
CoLa
Community and industry shorthand for IMAX Commercial Laser, the single-projector multiplex configuration. IMAX normally markets it simply as IMAX with Laser.
DCI
Digital Cinema Initiatives, the studio consortium whose system specification defines interoperable digital-cinema mastering and exhibition requirements.
DCP
Digital Cinema Package, the standardized set of picture, sound, subtitle, and metadata files delivered to a digital cinema server.
DLP Cinema
Digital projection technology built around a micromirror imaging device. IMAX xenon systems use modified DLP Cinema projectors.
DMR
Digital Media Remastering, IMAX’s process for preparing a separate picture and sound version for its theatres. It is not a camera format.
Dome
A tilted hemispherical screen that surrounds much of the audience. Dome projection uses fisheye optics and mapped imagery rather than a normal flat rectangle.
Expanded ratio
A taller composition supplied for some or all of an IMAX presentation. It reveals more vertical image only when the source and master contain it.
Field of view
The angle occupied by the screen from a seat. It changes with screen width and viewing distance.
Filmed for IMAX
IMAX’s production and mastering program for approved film or certified digital cameras. The label does not by itself specify the cinema projector.
Gauge
The nominal width of a strip of film. Gauge alone does not tell you frame size because orientation and perforations per frame also matter.
GT
Grand Theatre, IMAX terminology associated with purpose-built giant-screen systems. GT Laser is the dual-projector digital configuration capable of the full-height flat frame.
Laser XT
A lower-cost single-projector IMAX laser configuration for the common digital frame. Public technical documentation is less complete than for GT Laser.
Letterboxing
Unused bands above and below a wide image when it is shown inside a taller screen or canvas. The bands preserve the supplied composition.
Masking
Curtains or movable panels that hide unused parts of a cinema screen. Many modern premium rooms instead leave unused screen visible.
OMNIMAX
The original name for IMAX’s dome presentation. IMAX Dome is the current general name for the same basic concept.
Open matte
A taller version derived by using image area above and below a wider theatrical crop. It can create a taller IMAX master without IMAX camera capture.
Perf
Short for perforation, one of the holes along film used to transport and register it. The number per frame helps define a film format.
PLF
Premium large format, the cinema-industry category for upgraded large-screen experiences. It includes IMAX and competing branded or chain-owned formats.
Rake
The upward slope of seating rows. A steeper rake can preserve sightlines in front of a tall screen.
Rec. 2020
An ITU recommendation defining parameters for ultra-high-definition television, including a wide colour-gamut container. A projector may cover only part of it.
Resolution
The spatial detail a system can reproduce. Digital projectors have a pixel raster. Film does not have a native pixel count.
Rolling loop
The IMAX film-transport mechanism that forms moving loops, advances a large frame, and registers it steadily at the aperture.
Scope
The common modern wide theatrical image, conventionally described by the SMPTE projector-aperture ratio stored on this site.
Throw
The distance from the projection lens to the screen. It is a room-layout measurement, not the audience viewing distance.
Xenon
A bright arc-lamp light source. IMAX Digital xenon uses two overlaid digital projectors and the common digital frame.
Sources
- IMAX investor filing
- U.S. Securities and Exchange Commission filing: O54009e10vk
- Christie Digital: Christie Cp2000 Brochure
- Barco: Dp2k 32b
- Barco: 2012 12 14 Steen Iverson Founder Of Sirius 3d Teams Up With Imax
- Google Patents: En
- LF Examiner: The Imax Laser Dome System
- IMAX investor filing
- IMAX Corporation: Imax Laser Here
- PR Newswire: Imax Continues Roll Out Of Its Next Generation Laser Projection System At The Smithsonian And Pacific Science Center 300075990
- Science Museum: Science Museum Imax Re Opens December Latest Laser Technology And Original
- Screen Daily: 5089820.Article
- U.S. Securities and Exchange Commission filing: D876809d10k
- Barco: 2015 09 28 Presenting Laser Projection To The Giant Screen Cinema
- Ars Technica: Imax With Laser Superb Contrast 4k Resolution And Huge Colour Gamuts
- American Society of Cinematographers: Far And Away
- Associated Press
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- SMPTE publication: Eg0025 2003 Stable2009
- American Widescreen Museum: Wingup2
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- SMPTE publication: St0417 2005 Stable2015
- IMAX Corporation: Oppenheimer In Imax 70mm
- IMAX investor relations: Christopher Nolans Odyssey Delivers Record Breaking 52 Million
- Kodak: Dunkirk
- Collection.Sciencemuseumgroup: Imax Rolling Loop Cine Projector 1982 Projector Cine Camera Projector
- Google Patents: WO1997042544A1
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- IMAX Corporation: Experience Tenet IMAX 70mm
- Cgworld: 201601 Showing System
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- SMPTE publication: St0195 2000
- SMPTE publication: Rp0040 2003 Stable2016
- American Society of Cinematographers: Star Trek Into Darkness
- American Society of Cinematographers: Realism For Citizen Kane
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- IMAX Corporation: Imax Launches Next Generation Imax Laser Experience Enhance Blockbuster Moviegoing Amc
- U.S. Securities and Exchange Commission filing: Imax 10k 20191231
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- Digital Cinema Initiatives specification: DCSS
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- SMPTE publication: Eg0018 1994 Withdrawn2003
- THX: Thx Certified Screen Placement
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- SMPTE journal: 8
- Barco: R5914646
- Reddit community report: 137ydig
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