Editing IMAX (section)

==Technical aspects==
===Camera===
[[File:IMAX camera 1.jpg|thumb|An IMAX cinema camera, displayed at the [[National Science and Media Museum]], [[Bradford]], England]]

==== Film cameras ====

The IMAX cinema process increases the [[image resolution]] by using a larger film frame; in relative terms, a frame of IMAX format film has three times the theoretical horizontal resolution of a frame of [[35 mm movie film|35 mm film]].<ref name="Slash Film">{{cite web|url=https://www.slashfilm.com/film-interview-imax-executives-talk-the-hunger-games-catching-fire-and-imax-misconceptions/|title=/Film Interview: IMAX Executives Talk 'The Hunger Games: Catching Fire' and IMAX Misconceptions |publisher=Slash Film|date=December 2, 2013 |access-date=December 17, 2013}}</ref> To achieve such increased image resolution, which IMAX estimates at approximately 12,000 lines (6,000 line pair modulations) of horizontal resolution (18K),<ref name=imaxresolution /> [[65 mm film]] stock passes horizontally through the IMAX movie camera, 15 perforations at a time. At 24 frames per second, this means that the film moves through the camera at {{convert|102.7|m|sp=us}} per minute (just over 6&nbsp;km/h). In a conventional 65&nbsp;mm camera, the film passes vertically through the camera, five perforations at a time, or {{convert|34|m|sp=us}} per minute. In comparison, in a conventional 35&nbsp;mm camera, 35&nbsp;mm film passes vertically through the camera, at four (smaller) perforations at a time, which translates to {{convert|27.4|m|sp=us}} per minute.<ref name="Slash Film"/>

In the [[Todd-AO]] 70&nbsp;mm-format of widescreen cinema, the image area of a 65&nbsp;mm film-frame is {{convert|48.5|x|22.1|mm|in|abbr=on|sp=us}}; in the IMAX-format of widescreen cinema, the film-frame dimensions are {{convert|69.6|x|48.5|mm|in|abbr=on|sp=us}}. To match the standard image resolution of the moving image produced with the film-speed of 24 [[Frame rate|frames per second]], an IMAX film requires three times the length of (negative) film stock required for a 65&nbsp;mm film of comparable scope and [[Cinematography|cinematic technique]].

In March 2022, IMAX announced a new initiative in cooperation with [[Kodak]], [[Panavision]], and [[FotoKem]] to develop "a new fleet of next generation IMAX film cameras", with a goal to deploy the first four units in the next two years. [[Christopher Nolan]] and [[Jordan Peele]] are among a group of advisors, made up of filmmakers and cinematographers, assisting in identifying new specs and features for the prototype development phase.<ref name="IMAX Corporation">{{Cite web|url=https://www.imax.com/content/imax-to-develop-new-fleet-next-generation-imax-film-cameras|title=IMAX® to Develop new Fleet of Next Generation IMAX Film Cameras|date=March 22, 2022|website=www.imax.com}}</ref>

In a May 2024 interview with [[Collider (website)|Collider]], IMAX CEO [[Richard Gelfond]] revealed that there will be four new identical cameras that will be 30% quieter than the existing cameras.<ref>{{Cite web |last1=Weintraub |first1=Steven |last2=Jones |first2=Tamera |date=2024-05-20 |title=IMAX Reveals Their Ambitious 6-Year Plan to Expand Across the Globe |url=https://collider.com/imax-global-expansion-plans/ |access-date=2024-06-04 |website=Collider |language=en}}</ref> ''[[The Wall Street Journal]]'' revealed that the new cameras will be made out of carbon fiber and titanium, and they will feature a five inch color display along with wireless capability.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=6DAFkaGUiT4 |title=What Makes IMAX So Expensive? {{!}} WSJ Tech Behind |date=2024-02-29 |last=The Wall Street Journal |access-date=2024-06-04 |via=YouTube}}</ref>

====Phantom 65 IMAX 3D digital camera====
In 2011, IMAX announced a 4K 3D digital camera. The camera was developed alongside [[Vision Research (company)|Vision Research]] and AbelCine, integrating two Phantom 65 engines. A prototype camera was used for the documentary ''[[Born to Be Wild (2011 film)|Born to be Wild]]'', in which approximately 10% of the finished film was shot with the system.<ref>{{cite web|url=http://blog.abelcine.com/2011/05/05/phantom-65-in-the-wild-for-imax-3d-shoot/|title=Phantom 65 used in the "Wild for IMAX 3D shoot|publisher=abelcine.com|date=May 2012|url-status=dead|archive-url=https://web.archive.org/web/20121020100533/http://blog.abelcine.com/2011/05/05/phantom-65-in-the-wild-for-imax-3d-shoot/|archive-date=October 20, 2012|df=mdy-all}}</ref> The company has said they have no intention of replacing the higher resolution film cameras with the new digital camera, but the latter can be used in scenes that require a lightweight or relatively small 3D camera. While IMAX has completed the production camera and has placed it in service on several films, they have no plans to produce an IMAX film solely with the new digital system. ''[[Transformers: Age of Extinction]]'' is the first feature film partially filmed with the Phantom 65 IMAX 3D camera.<ref>{{cite web|url=http://www.tvbeurope.com/newsletter-3dmasters-content/full/imax-debuts-digital-3d-camera|title=IMAX debuts digital 3D camera|publisher=tvbeurope.com|date=May 2012|url-status=dead|archive-url=https://web.archive.org/web/20130825144559/http://www.tvbeurope.com/newsletter-3dmasters-content/full/imax-debuts-digital-3d-camera|archive-date=August 25, 2013|df=mdy-all}}</ref>

====Arri Alexa IMAX digital camera====
In 2015, IMAX announced a 2D digital camera that was developed alongside [[Arri]], the camera being based on the latter company's [[Arri Alexa|Arri Alexa 65]] technology. The first production to use the camera was ''[[Captain America: Civil War]]''. The [[Russo brothers]] have stated that they solely used the Arri Alexa IMAX on ''[[Avengers: Infinity War]]'' (2018) and ''[[Avengers: Endgame]]'' (2019).<ref name="captain-america">{{cite web|url=https://variety.com/2015/film/news/captain-america-civil-war-first-to-use-new-imaxarri-2d-camera-exclusive-1201470965/|title='Captain America: Civil War' First to Use New Imax/Arri 2D Camera (Exclusive)|last=Lang|first=Brent|date=April 13, 2015|work=[[Variety (magazine)|Variety]]|access-date=April 13, 2015|archive-url=https://web.archive.org/web/20150414180557/http://variety.com/2015/film/news/captain-america-civil-war-first-to-use-new-imaxarri-2d-camera-exclusive-1201470965/|archive-date=April 14, 2015|url-status=live}}</ref>

For ''[[Transformers: The Last Knight]]'', two Arri Alexa IMAX cameras were combined in a rig to provide native 3D, with the film containing 98% of IMAX footage.<ref>{{cite web|url=http://www.filmjournal.com/features/ready-prime-time-michael-bay-helms-fifth-episode-transformers-series-native-real-time-3d|title=Ready for Prime Time: Michael Bay helms fifth episode in the Transformers series in native, real-time 3D|last=Eagan|first=Daniel|date=June 12, 1017|access-date=November 24, 2017|url-status=dead|archive-url=https://web.archive.org/web/20170706043717/http://www.filmjournal.com/features/ready-prime-time-michael-bay-helms-fifth-episode-transformers-series-native-real-time-3d|archive-date=July 6, 2017}}</ref>

==== IMAX certified cameras ====
In September 2020, IMAX launched the "Filmed for IMAX" program, which certifies high-quality digital cameras that can be used to create IMAX-format films. As the scope of certified cameras expands, it will be easier for filmmakers to create films to meet the projection needs of the IMAX giant screen theater.
{| class="wikitable"
|+
!IMAX certified cameras
|-
|Arri Alexa LF (4.5K camera)
|-
|Arri Alexa Mini LF (4.5K camera)
|-
|Panavision Millennium DXL2 (8K camera)
|-
|Red Ranger Monstro (8K camera)
|-
|Red V-Raptor (8K camera)
|-
|Sony CineAlta Venice (6K camera)
|-
|Arri Alexa 65 IMAX (6.5K camera)
|}
''[[Top Gun: Maverick]]'' (shot with the Sony CineAlta Venice) and ''[[Dune (2021 film)|Dune]]'' (shot with the Arri Alexa LF and Mini LF) were among the first films that used IMAX-certified cameras.<ref name="filmed-in-IMAX">{{cite web|date=2020-09-17|title=IMAX® Launches New "Filmed in IMAX" Program with World's Leading Digital Camera Brands|url=https://www.imax.com/content/imax-launches-new-filmed-imax-program-worlds-leading-digital-camera-brands|access-date=2021-08-08|website=www.imax.com|language=en}}</ref> Other films between 2021 and 2023 that captured with this program are ''[[The Suicide Squad (film)|The Suicide Squad]]'' (shot with the Red Ranger Monstro and Komodo), ''[[Shang-Chi and the Legend of the Ten Rings]]'' (shot with the Arri Alexa LF and Mini LF), ''[[The Battle at Lake Changjin]]'' and ''[[The Battle at Lake Changjin II]]'' (shot with the Red Ranger Monstro), ''[[Eternals (film)|Eternals]]'' (shot with the Arri Alexa LF and Mini LF), ''[[Doctor Strange in the Multiverse of Madness]]'' (shot with Panavision Millennium DXL2), ''[[Thor: Love and Thunder]]'' (shot with the Arri Alexa LF and Mini LF), ''[[Black Panther: Wakanda Forever]]'' (shot with the Sony CineAlta Venice), ''[[Guardians of the Galaxy Vol. 3]]'' (shot with the Red V-Raptor),<ref name="auto3">{{Cite web|url=https://ymcinema.com/2022/12/12/imax-certifies-the-red-v-raptor-as-a-filmed-for-imax-camera/|title=IMAX Certifies the RED V-Raptor As a "Filmed For IMAX" Camera|first=Yossy|last=Mendelovich|date=December 12, 2022}}</ref> ''[[The Marvels]]'' (shot with the Arri Alexa LF and Mini LF)<ref>{{cite web |url=https://imaxcorporation.gcs-web.com/static-files/c9f18bad-2328-4ee8-94f3-2ad09d8b7fa7 |title=Second Quarter 2021 Financial Results |publisher=IMAX |date=July 27, 2021 |access-date=July 22, 2022}}</ref> and ''[[Dune: Part Two]]'' (shot with the Arri Alexa LF and Mini LF).<ref name="comingsoon.net">{{cite web|url=https://www.comingsoon.net/movies/news/1214754-dune-part-2s-screenplay-finished-feature-more-imax-footage|title=Dune: Part 2's Screenplay is Finished, Film to Feature More IMAX Footage|date=March 15, 2022}}</ref>

=== Film stock ===

The IMAX format is generically called "15/70" film, the name referring to the 15 sprocket holes or perforations per frame. The film's bulk and weight require horizontal platters, rather than conventional vertically mounted film reels. IMAX film is fed through the projector horizontally,<ref>{{cite web|last=Brain |first=Marshall |url=https://entertainment.howstuffworks.com/imax1.htm |title=Howstuffworks 'How IMAX Works' |date=August 3, 2001 |publisher=Howstuffworks.com | access-date=August 14, 2020}}</ref> and the film is drawn from the inner circumference of the platter, not from the outer circumference like in conventional film reels. A system is in place to keep the film in the outer circumference from flying outwards due to centrifugal force while the platter is spinning. IMAX film is shipped to theaters in several small reels that are spliced into one continuous length that is then wound into a platter, a process that may take hours to complete. Films may be several kilometers in length: ''Avatar'', which was 2:45 hours in duration, was close to {{convert|16|km|abbr=on|sp=us}} long. Platters are handled using special forklifts.<ref name="auto1">{{cite web|url=https://www.desmoinesregister.com/story/entertainment/movies/2015/12/16/facts-blank-dome-imax/77427476/|title=10 facts about Des Moines' Blank IMAX|first1=Courtney|last1=Crowder|first2=Jessica|last2=Knight|website=Des Moines Register}}</ref>  IMAX platters range from {{convert|1.2|to|1.83|m|ft|abbr=on|sp=us}} diameter to accommodate 1 to 2.75 hours of film. Platters with a 2.5 hour feature film weigh {{convert|250|kg|lb|abbr=on|sp=us}}. IMAX uses ESTAR-based print film<ref>Kodak's trade name for biaxially oriented PET film</ref> in their 15/70 rolling-loop film projection systems. ESTAR-based print film provides greater precision. The chemical development process does not change the size or shape of ESTAR print film, and IMAX's pin registration system (''especially that of the camera mechanism'') does not tolerate either [[sprocket]]-hole or film-thickness variations, but the film can still swell or shrink under varying temperature and humidity. This requires projection booths to be kept at a temperature of between 20 and 23.8&nbsp;°C and a humidity of 50%.<ref name="auto1"/> The film is too large to be moved using its sprockets,<ref name="auto2">{{cite web|url=https://entertainment.howstuffworks.com/imax.htm|title=How IMAX Works|date=August 3, 2001|website=HowStuffWorks}}</ref> so they are instead used for registration, to aid in aligning the film. A feature film platter can cost {{US$|36000|link=yes}} to print. The camera negative is actually 65&nbsp;mm film stock, but it runs horizontally and with 15 perforations per frame.<ref name="auto">{{cite web|url=https://www.redsharknews.com/technology-computing/item/1754-the-staggering-size-and-scale-of-imax|title=The staggering size and scale of IMAXr|website=Redsharknews.com}}</ref> The camera, like the projector, has a vacuum system; this makes the camera noisy, forbidding the [[sync-sound]] recording of quiet scenes. The camera has enough film for three minutes of shooting. The large frame of the film also imposes optical limitations such as an extremely shallow [[depth of field]] when shooting with an open aperture.<ref>{{cite web|url=https://ymcinema.com/2020/03/10/imax-filmmaking-what-is-it-like-to-shoot-on-an-imax-film-camera/|title=IMAX Filmmaking: What is it like to Shoot on an IMAX Film Camera?|first=Yossy|last=Mendelovich|website=Ymcinema.com|date=March 10, 2020}}</ref>

=== Soundtrack &ndash; double-system ===

To use more of the image area, IMAX film does not include an embedded soundtrack. Instead, the IMAX system specifies a separate six-channel {{convert|35|mm|in|abbr=on|sp=us}} magnetic film, recorded and played back on a [[Sound follower|film follower]] locked to picture, just as [[Vitaphone]] had been (utilizing 16-inch 33 1/3 RPM [[Old-time radio#Electrical transcription discs|electrical transcription discs]]) in the early 20th century, and was the same technology used to provide the 7-channel soundtrack accompanying films photographed and exhibited in the [[Cinerama]] process in the mid-1950s. By the early 1990s, a separate [[DTS (sound system)|DTS]]-based 6-track digital sound system was used, similarly locked to the projector by a [[SMPTE time code]] synchronization apparatus, the audio played off a series of proprietarily encoded [[CD-ROM]] discs. In the late 1990s, IMAX upgraded this system to use a [[hard disk drive|hard drive]] that carries a single uncompressed [[Audio file format|audio]] file. These are converted directly to analogue rather than processed through a decoding method such as [[DTS (sound system)|DTS]].  IMAX film and IMAX digital cinemas utilise a 6-channel surround sound system - with Left, Centre, Right speakers behind the screen similar to conventional cinemas, plus an additional "top center" speaker to create the effect of height in the screen.<ref>{{cite web |date=June 1, 1999 |title=Big Enough for Everest: Inside IMAX Sound |url=http://www.creativeplanetnetwork.com/news/news-articles/big-enough-everest-inside-imax-sound/373444 |access-date=April 26, 2017 |publisher=DigitalContentProducer.com}}</ref> There are also 2 rear left and rear right surround sound speaker, arranged as clusters of speakers rather than a spaced array of speakers such as used in a Dolby surround sound system. IMAX with Laser adds another 6 channels of sound: 4 channels of overhead speakers plus 2 extra side surround speakers.<ref>{{Cite web |title=The IMAX Difference {{!}} IMAX Melbourne |url=https://imaxmelbourne.com.au/about_imax/the_imax_difference/ |access-date=2024-06-04 |website=imaxmelbourne.com.au}}</ref>