275:) perforations are used on camera negative film and have straight tops and bottoms with outward curving sides; they have been in use since the beginning of the 20th century. The BH perforation is a circle of approximately diameter 0.110" (2.79 mm), with flattened sides giving a height of approximately 0.073" (1.85 mm). The corners used to be sharp, but were slightly rounded in 1989 by 0.005" (0.127 mm) to give them greater strength. The BH1866 perforation, or BH perforation with a
253:
25:
122:
403:). Their dimensions are 0.0730" (1.85 mm) in width by 0.0780" (1.98 mm) in height. Due to the size difference, CS perfed film cannot be run through a projector with standard KS sprocket teeth, but KS prints can be run on sprockets with CS teeth. CS-perforated stock has fallen out of use since the 1970s when 35 mm prints with magnetic sound became uncommon.
464:) or both sides (35 mm and 65/70 mm). Standard 16 mm can be either single or double perf; some older cameras require double perf, but most can handle either. Because most cameras can handle both, and because of the increased popularity of Super 16 film, most 16 mm stock manufactured today is single perf unless requested otherwise.
411:
Standard 17.5 mm magnetic film uses 35 mm magnetic film which has been slit lengthwise into two equal widths and lengths before use. The "heads" of one-half of the 35 mm donor become the "heads" of one 17.5 mm length while the "tails" of one-half of the 35 mm donor become the
420:
for location dialogue recording ; it was most often run at 45 feet/minute, one-half of the usual 35 mm magnetic film speed, thereby achieving a 4-to-1 increase in economy although at a significant sacrifice in sound fidelity, but adequate for monophonic dialogue. For stereophonic dialogue,
333:
recommendation and standard was adopted by the
Eastern Bloc, but was wholly rejected by the very bloc which proposed its adoption. To this day, all Western Bloc professional cameras employ BH perforations, and so also do the intermediate applications (interpositives and internegatives, also known as
229:
motion picture film, there are two different pitches—short pitch (camera stocks intended for duplication or printing, and for most intermediate applications) and long pitch (camera stocks intended for direct projection, print stocks, and special intermediate applications, as well as 135 still camera
484:
Damaged or broken perforations can lead to a tear in the film as it runs through the projector. Film is commonly checked for broken sprocket holes before presentation, a process known as "spooling". Mechanical devices exist for this purpose, but the classic method is to place the finger and thumb
365:
The Dubray Howell (DH) perforation was first suggested in 1931 to replace both the BH and KS perfs with a single standard perforation which was a hybrid of the two in shape and size, being like KS a rectangle with rounded corners and a width of 0.1100" (2.79 mm), but with BH's height of 0.073"
436:
All 16 mm perforations are rectangles with rounded corners and are 0.0500" (1.27mm) high by 0.078" (1.9812mm) wide. The tolerance for these perforation dimensions was reduced to 0.01 mm in 1989, which allowed 16 mm camera manufacturers to slightly enlarge their registration pins and
341:
One aspect of this particular adoption was that it effectively prevented amateur camera films from being "diverted" to professional uses, as KS-perforated camera film will indeed pass undamaged through a
Western Bloc professional camera, but it cannot maintain the required registration accuracy as
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coated on the film)—required another type of perforation. CinemaScope perforations are similar to KS perforations, but almost square in shape to accommodate the magnetic stripes. These perfs are commonly referred to as CinemaScope (CS) or "Fox hole" perforations, or simply "Foxholes" (because,
356:
65/70 mm, the other "professional" standard, was created many years after KS perforations had been recommended for negative as well as positive applications, and was adopted for positive applications. Consequently, 65/70 mm uses only KS perforations for all applications, negative,
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and its satellites) adopted KS for these uses. The
Western Bloc countries maintained BH perforations for negative and intermediate films, but adopted KS perforations for positive print films and for amateur films which were on a 35 mm wide base.
424:
For final mixing, the 17.5 mm dialog was usually initially copied to a 35 mm center track or full coat magnetic film element, whereby the dialog track entered the conventional mixing process as a second-generation 35 mm duplicate.
213:. This description does not indicate whether the film transport is horizontal or vertical, but uncertainty is precluded because there are currently no horizontal systems using the same number of perforations on the same gauge as a vertical one.
475:
used a single perforation in the middle of the frame line between each image. This is however considered a liability, since any sprocket or claw error will likely damage the center of the frame itself rather than the outer edges.
314:, but failed to displace BH perforations for filming operations prior to projection. KS perfs are rectangular with rounded corners, and measure 0.0780" (1.981 mm) in height by 0.1100" (2.794 mm) in width.
345:
The increased height also means that the image registration was considerably less accurate than with BH perfs, which remain the standard for negatives. The KS1870 perforation, or KS perforation with a
310:
Standard) perforations were introduced in the 1920s to improve the life of projected film stock by eliminating the sharp corners which were prone to tearing. and thus are occasionally used for
552:
With the advent of lower shrinkage acetate film, pre-print films had to be perforated with a shorter pitch to work well on contact printers designed for the 0.3 percent shrinkage of nitrate.
240:
naturally shrank about 0.3% in processing due to heat, so film printing equipment was designed to account for a size difference between its (processed) input and (unprocessed) output. When
532:
230:
film). For 35 mm film these are 0.1866" and 0.1870" (4.740 mm and 4.750 mm); for 16 mm film they are 0.2994" and 0.3000" (7.605 mm and 7.620 mm).
291:) lab film. The BH1870 perforation, or BH perforation with a pitch of 0.1870", was the original standard for positive prints intended for direct projection (
378:
film in the 1950s reduced the demand for dye transfer, although the DH perf persists in intermediate films to this day, such as long-pitch interpositives
221:
One of the characteristics of perforations is their "pitch". This is the measurement of the distance between the tops of two sequential perforations. For
648:
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of a gloved hand on the edges of the film, which is mounted on a winding bench, and to slowly run the film through the fingers, feeling for snags.
448:
uses 16 mm film that is perforated twice as frequently (half the pitch of normal 16 mm) and then split down the middle after development.
178:
Some formats are referred to in terms of the ratio "perforations per frame/gauge size" to provide an easy way of denoting size. For instance,
171:, and intended usage. Perforations are also used as a standard measuring reference within certain camera systems to refer to the size of the
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uses much narrower perfs on film which is already 8 mm wide. Super 8 pitch is 0.1667" and perfs are 0.045" high by 0.036" wide.
758:
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366:(1.85 mm). This gave it longer projection life and also improved registration. One of its primary applications was usage in
89:
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thus improve image registration and steadiness tolerances to less than 1/750th of the image height of the 16 mm frame.
68:
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17.5 mm film, in this context, is for magnetic sound elements only, and only for very cost-conscious producers.
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412:"heads" of the other 17.5 mm length. 17.5 mm magnetic film was used as a secondary "shop standard" at
46:
57:
644:
698:"KODAK VISION Color Intermediate Film / 5242, 7242, 2242, 3242 KODAK Publication No. H-1-5242t CAT 123 9607"
244:
was developed, which does not shrink, two forms were produced for compatibility with existing equipment.
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All of the systems described above place the perforations down either one side (Standard and Super 8,
569:"'Managing' the Moving Image From an Engineering Point of View Part 2: A Perspective on Perforations"
509:
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the KS perforation is too tall relative to the professional camera's BH-sized registration pin(s).
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Additionally, for 35 mm film only, there are several different shapes for these perforations.
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KS perforations were once recommended for negative and intermediate films, too, but only the
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394:—with its wider picture area and its use of four-track magnetic sound (four strips of
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374:(dye transfer). The DH perf never caught on, and Kodak's introduction of monopack
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Society of Motion
Picture and Television Engineers. White Plains, NY.
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Society of Motion
Picture and Television Engineers. White Plains, NY.
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of 0.1870", is the modern standard for release prints as well as for
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SMPTE Standard for Motion-Picture Film (35mm) – Perforated CS-1870.
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645:"Technical Glossary of Common Audiovisual Terms: Perforations"
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SMPTE STANDARD for Motion-Picture Film (35mm) – Perforated KS.
533:"Why Do Sound Negative Films Use Kodak Standard Perforations?"
536:
307:
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156:
665:
The Camera
Assistant: A Complete Professional Handbook
256:
The shapes and dimensions of 35 mm sprocket holes
147:during manufacturing and used for transporting (by
49:. Unsourced material may be challenged and removed.
125:Perforations on Standard (left) and Super (right)
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421:conventional 35 mm magnetic film was used.
329:This was one of the very few instances where a
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399:initially, all CinemaScope films were made by
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109:Learn how and when to remove this message
16:Functional element in motion picture film
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279:of 0.1866", is the modern standard for
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233:This distinction arose because early
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159:. Films may have different types of
47:adding citations to reliable sources
18:
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13:
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791:description of inspection process
728:(4th ed). Eastman Kodak Company.
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567:Zavada, Roland J. (April 1998).
23:
782:
751:
34:needs additional citations for
726:Kodak Motion Picture Film (H1)
605:Motion Picture Film Processing
467:Some obsolete formats such as
143:, are the holes placed in the
1:
680:. Retrieved August 11, 2006.
647:. Retrieved August 11, 2006.
515:
390:In 1953, the introduction of
151:and claws) and steadying (by
667:. Focal Press: Boston, 1996.
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382:from short-pitch negatives.
7:
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357:intermediate and positive.
10:
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684:September 4, 2006, at the
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808:Film and video technology
510:Sprocket hole photography
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194:; the long-time standard
707:. August 2006. p. 6
651:August 21, 2006, at the
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643:ScreenSound Australia,
607:. Boston: Focal Press.
446:Standard 8 mm film
440:
372:dye imbibition printing
603:Case, Dominic (1985).
257:
242:cellulose acetate film
129:
744:ANSI/SMPTE 102-1997.
705:Eastman Kodak Company
627:ANSI/SMPTE 139-1996.
578:: 2–5. Archived from
480:Damage and inspection
471:and some variants of
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360:
351:135 still camera film
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495:List of film formats
43:improve this article
759:"Film preservation"
58:"Film perforations"
312:high-speed filming
283:and intermediate (
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130:
663:Hart, Douglas C.
500:Negative pulldown
473:17.5 mm film
182:is also known as
133:Film perforations
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585:on March 4, 2016
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543:on March 3, 2012
539:. Archived from
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469:9.5 mm film
401:20th Century Fox
153:pin registration
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773:. Retrieved
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580:the original
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545:. Retrieved
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407:17.5 mm
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41:Please help
36:verification
33:
789:FilmForever
392:CinemaScope
368:Technicolor
203:5 perf-70mm
192:8 perf-35mm
188:VistaVision
184:4 perf-35mm
169:film format
775:2007-12-31
589:2015-04-23
547:2015-04-23
516:References
432:16 mm
338:process).
165:film gauge
145:film stock
99:March 2023
69:newspapers
456:Placement
441:8 mm
418:Universal
414:Paramount
238:film base
149:sprockets
127:8 mm film
802:Category
682:Archived
649:Archived
505:Super 35
489:See also
462:Super 16
281:negative
711:10 June
450:Super 8
196:Todd-AO
83:scholar
732:
611:
248:Shapes
205:; and
155:) the
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769:(PDF)
762:(PDF)
701:(PDF)
583:(PDF)
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537:Kodak
347:pitch
336:IP/IN
308:Kodak
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223:35mm
217:Pitch
173:frame
137:perfs
90:JSTOR
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730:ISBN
713:2015
609:ISBN
416:and
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225:and
207:IMAX
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370:'s
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209:is
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190:is
45:by
804::
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636:^
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361:DH
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304:KS
299:KS
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269:BH
264:BH
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