Editing 70 mm film (section)

===Blow-ups===
The 35&nbsp;mm to 70&nbsp;mm "blow-up" process produces 70&nbsp;mm release prints from 35&nbsp;mm negatives, so that films shot on the smaller format could benefit from 70&nbsp;mm image and sound quality. This process began in the 1960s with titles like ''[[The Cardinal (film)|The Cardinal]]'' (1963)<ref>{{cite web |title=The Beginning of the End |url=http://www.widescreenmuseum.com/widescreen/35-70mm.htm |website=in70mm |access-date=8 February 2019}}</ref> and continues up until the present day, with the height of its popularity being in the 1980s. These enlargements often provided richer colors, and a brighter, steadier and sharper (though often grainier) image, but the main benefit was the ability to provide 6-channel stereophonic sound as most theaters before the mid-70s (before the advent of [[Dolby noise reduction|Dolby A]]) were screening 35&nbsp;mm prints with single channel [[monaural]] sound.<ref name="Celestino2014" /> However these "blow-ups" rarely used the full six channels of the [[Todd-AO]] system and instead used the four-track mixes made for 35&nbsp;mm prints, the additional half-left and half-right speakers of the [[Todd-AO]] layout being fed with a simple mix of the signals intended for the adjacent speakers (known as a "spread") or simply left blank.<ref name="ReferenceA">"Mixing Dolby Stereo Film Sound" Larry Blake Recording Engineer/Producer Vol12 No.1 Feb 1981</ref> If a 70&nbsp;mm film was shown in a Cinerama theatre, the [[Cinerama]] sound system was used. From 1976 onwards, many 70&nbsp;mm prints used Dolby noise reduction on the magnetic tracks but Dolby disapproved of the "spread" and instead re-allocated the 6 available tracks to provide for left, center and right screen channels, left and right surround channels plus a "low-frequency enhancement" channel to give more body to low-frequency bass.<ref>The CP200 – A Comprehensive Cinema Theater Audio Processor David Robinson Journal of the SMPTE Sept 1981</ref> This layout came to be known as "[[5.1 surround sound|5.1]]" (the "point one" is the low-frequency enhancement channel) and was subsequently adopted for digital sound systems used with 35&nbsp;mm.

In the 1980s the use of these "blow-ups" increased with large numbers of 70&nbsp;mm prints being made of some blockbusters of the period such as the 125 70&nbsp;mm prints made of ''[[The Empire Strikes Back]]'' (1980).<ref name="ReferenceA"/> However the early 1990s saw the advent of digital sound systems ([[Dolby Digital]], [[DTS (sound system)|DTS]] and [[Sony Dynamic Digital Sound|SDDS]]) for 35&nbsp;mm prints which meant that 35&nbsp;mm could finally match 70&nbsp;mm for sound quality but at a far lower cost. Coupled with the rise of the multiplex cinema, which meant that audiences were increasingly seeing films on relatively small screens rather than the giant screens of the old "Picture Palaces", this meant that the expensive 70&nbsp;mm format went out of favour again. The [[DTS (sound system)#DTS 70 mm|DTS]] digital sound-on-disc system was adapted for use with 70&nbsp;mm film, thus saving the significant costs of magnetic striping, but this has not been enough to stop the decline, and 70&nbsp;mm prints were rarely made.

Among some of the more recent 70&nbsp;mm blow-up titles are [[Paul Thomas Anderson]]'s [[Inherent Vice (film)|''Inherent Vice'']] (2014)<ref name="Celestino2014" /> and ''[[Phantom Thread]]'' (2017), [[Patty Jenkins]]'s [[Wonder Woman (2017 film)|''Wonder Woman'']] (2017),<ref>{{cite web |title=70 mm Blow Ups 2017 |url=https://www.in70mm.com/library/blow_up/year/2017/index.htm |website=in70mm |access-date=8 February 2019 |archive-date=9 February 2019 |archive-url=https://web.archive.org/web/20190209180121/https://www.in70mm.com/library/blow_up/year/2017/index.htm |url-status=dead }}</ref> and [[Steven Spielberg]]'s [[Ready Player One (film)|''Ready Player One'']] (2018).<ref>{{cite web |title='Ready Player One' in 70 mm Film Opens on 22 Screens |url=https://www.hollywoodreporter.com/behind-screen/ready-player-one-70mm-film-opens-22-screens-1098364 |website=Hollywood Reporter |access-date=8 February 2019}}</ref>