35mm film
| image:35mm.jpg Simulated 35mm filmsoundtracks The outermost strips (on either side) containSDDS soundtrack as an image ofdigital signal. In from them areperforations useddrivefilm throughprojector, alongthe Dolby Digital soundtrack between them. Onleft side only the two tracksanalog soundtrack can be seen, often encoded using Dolby Surroundsimulatethird track. Justfromanalog track istimecode usedsynchronizeDTS soundtrack. Finally, incenter, isimage,this case compressed horizontally by Cinemascope (This imagelicenseduse under GFDL) |
35mm film isbasic film format most commonly usedboth still photographymotion pictures,remains relatively unchanged since its introduction1889 by Thomas Edison. The photographic filmcut into strips 35 millimeterss wide,six perforations per inch (25.4mm) along both edges
The origin for35 mm sizean Eastman Kodak 70 mm roll filmphotography, being cuttwo. William Kennedy Laurie Dickson, workingEdison, then cut four round perforations per frame along both edges. The format was initially called Edison size. The flattened perforations were introduced by Bell & Howell around 1900, which remainthis daycamera original film. Kodak-Standard perforations were introduced some ten years laterprojection use.
A variation used byLumière Brothers usedsingle circular perforation incentre offilm between frames.
The film format was introduced into still photography as early as 1913 (the Tourist Multiple) but first became popular withlaunch ofLeica camera, created by Oskar Barnack. In normal still photography use,film,Kodak Standard perforations,used horizontally,each frame having an aspect ratio2:3,size24 x 36 mm. See135 film section.
Inconventional motion picture format, framesfour perforations tall,an aspect ratioabout 4:3. Still cameras35mm andVistavision motion picture format usehorizontal frame witheight perforations wide, resulting inwider aspect ratio3:2greater detail, as more film areaused per frame.
The commonly used anamorphic widescreen format Cinemascope usesconventional four-perf frame, but an anamorphic lensused on bothcameraprojectorproducewider image, todayan aspect ratioabout 2.35. The image as stored onfilm appears horizontally compressed.
Most films todayshotprojected using4-perforation format, but croppingtopbottom offrames formedium aspect ratio1.85 or 1.67. In television production, where compatibilityan installed base35mm film projectorsunnecessary,3-perf formatcommonly used, giving16:9 ratio used by HDTVreducing film usage by 25%.
When sound was introduced tocinema, after some initial attempts at using synchronized record cylinders, etc.,sound startedbe stored optically directly onfilm. This analog soundtrack takes upsmall strip toleft ofpicture area. The aspect ratiosilent movies was 1:1.33. Afterintroductionsoundwas changed1:1.37 (known as standard or Academy ratio) byAcademyMotion Picture ArtsScience.
New digital soundtracks introduced since1990s include Dolby Digital, whichstoredbetweenperforations; SDDS, storedtwo strips alongoutside edges (beyondperforations),DTS, where sound datastored onseparate compact disc synchronized bytimecode track stored onfilm just toleft ofanalog soundtrack. Because all these soundtrack systems appear on different parts offilm, one movie can contain allthembe played inwidest possible numbertheaters.
