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36-577: Invention of the Latham loop is usually credited to film pioneers William Kennedy Laurie Dickson and Eugene Lauste . Both men worked with Woodville Latham , developing a motion picture camera and projector in 1895. Dickson later acknowledged Lauste as inventor of the loop, though rival claims were made in support of another Latham associate, engineer Enoch J. Rector , who used the technology to shoot an hour-and-a-half-long documentary film , The Corbett-Fitzsimmons Fight , in 1897. Woodville Latham applied for

72-505: A movie projector system, they hired former Edison employee Eugene Lauste , probably at Dickson's suggestion. In April 1895, Dickson left Edison's employ and provided some assistance to the Latham outfit. Alongside Lauste, he may have devised what would become known as the Latham loop , allowing the photography and exhibition of much longer filmstrips than had previously been possible. This idea had first been made public in 1890 in descriptions of

108-464: A Western Bloc professional camera, but it cannot maintain the required registration accuracy as the KS perforation is too tall relative to the professional camera's BH-sized registration pin(s). 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 pitch of 0.1870",

144-414: A federal court upheld the validity of the Latham patent. This film technology article is a stub . You can help Misplaced Pages by expanding it . William Kennedy Laurie Dickson William Kennedy Laurie Dickson (3 August 1860 – 28 September 1935) was a British - American inventor who devised an early motion picture camera under the employment of Thomas Edison . William Kennedy Dickson

180-492: A fourth caveat and ordered the team to change direction to work with rolls of film. William Dickson collaborated with the Eastman company to develop a practical celluloid film for this application. Initially using 19mm film, fed horizontally, shooting circular images, Dickson eventually settled on 35 mm film with a 1.33:1 picture ratio, a standard format which is still in use to this day in cinema. William Dickson and his team, at

216-549: A letter to American inventor and entrepreneur Thomas Edison seeking employment. He was turned down. That same year Dickson, his mother, and two sisters moved from Britain to Virginia. In 1883 he was finally hired to work at Edison's laboratory in Menlo Park, New Jersey . In 1888, Edison conceived of a device that would do "for the Eye what the phonograph does for the Ear". In October, Edison filed

252-409: A patent on June 1, 1896. In his patent application, Latham wrote, By 1905, virtually all motion picture projectors used the Latham loop. The patent expired in 1913. When Thomas Edison excluded his competitor Biograph from licensing Edison's key motion picture patents in 1907, Biograph retaliated by purchasing the patent for the Latham loop. In a patent infringement suit by Edison against Biograph,

288-655: A pitch of 0.1870", was the original standard for positive prints intended for direct projection ( release prints ). KS ( Kodak 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 high-speed filming , 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. KS perforations were once recommended for negative and intermediate films, too, but only

324-611: A preliminary claim, known as a caveat, with the United States Patent and Trademark Office ; outlining his plans for the device, subsequently named the Kinetoscope . Dickson, then the Edison company's official photographer, was assigned to turn the concept into a reality. Initial attempts were focused on recording micro-photographs on a cylinder. In late 1889, inspired by a recent encounter with Étienne-Jules Marey , Edison came up with

360-399: A standard measuring reference within certain camera systems to refer to the size of the frame . 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, 35mm Academy is also known as 4 perf-35mm ; VistaVision is 8 perf-35mm ; the long-time standard Todd-AO 70 mm film is 5 perf-70mm ; and IMAX

396-1063: Is 15 perf-70mm . 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. One of the characteristics of perforations is their "pitch". This is the measurement of the distance between the tops of two sequential perforations. For 35mm and 16mm 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 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). This distinction arose because early nitrocellulose film base naturally shrank about 0.3% in processing due to heat, so film printing equipment

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432-439: Is the modern standard for release prints as well as for 135 still camera film . 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, intermediate and positive. The Dubray Howell (DH) perforation

468-514: The Eastern Bloc countries (the Soviet Union 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. This was one of the very few instances where a Western Bloc recommendation and standard was adopted by

504-456: The Kinetograph , a motion picture camera to photograph films for in-house experiments and eventually, commercial Kinetoscope presentations, at speeds of up to 46 frames per second. To govern the intermittent movement of the film in the camera, allowing the strip to stop long enough so each frame could be fully exposed and then advancing it quickly (in about 1/460 of a second) to the next frame,

540-541: The 1950s reduced the demand for dye transfer, although the DH perf persists in intermediate films to this day, such as long-pitch interpositives contact-printed from short-pitch negatives. In 1953, the introduction of CinemaScope —with its wider picture area and its use of four-track magnetic sound (four strips of magnetic tape coated on the film)—required another type of perforation. CinemaScope perforations are similar to KS perforations, but almost square in shape to accommodate

576-442: The 1970s when 35 mm prints with magnetic sound became uncommon. 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 "heads" of the other 17.5 mm length. 17.5 mm magnetic film

612-586: 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 the IP/IN process). 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

648-604: The Edison lab, simultaneously worked on the development of the Kinetoscope viewing machine. The first working prototype, using the 19mm film, was unveiled in May 1891 to a meeting of the National Federation of Women's Clubs, hosted by his wife. The 35mm camera was essentially finalised by the fall of 1892. The completed version of the 35mm Kinetoscope was unveiled at the Brooklyn Institute of Arts and Sciences on 9 May 1893. It

684-693: The United Kingdom in 1897 for the British side of the company. William Dickson was the first person to make a film of the Pope , and at the time his Biograph camera was blessed by Pope Leo XIII . The Mutoscope machines produced moving images by means of a revolving drum of photographs/frames, similar in concept to flip-books , taken from an actual piece of film. They were often featured at seaside locations, showing (usually) sequences of women undressing or acting as an artist's model. In Britain, they became known as " What

720-531: 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 pitch of 0.1866", is the modern standard for negative and intermediate ( interpositive / internegative ) lab film. The BH1870 perforation, or BH perforation with

756-464: The butler saw " machines, taking the name from one of the first and most famous softcore reels. His association with Biograph ended inexplicably in 1911. Dickson spent his last years quietly in his house in Twickenham, England. He died on September 28, 1935, at the age of 75. He died without being given credit for his contributions to the history of modern filmography. This omission was corrected by

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792-485: The exhaustive research of Gordon Hendricks and Paul Spehr who revealed the full extent of his contributions to many moving picture projects. Dickson was the first to direct and likely star in a film with live recording. In 1894, he directed The Dickson Experimental Sound Film . A man (likely Dickson) played "The Song of the Cabin Boy" on the violin into a megaphone used for a partially off-camera phonograph . The film

828-412: The frame itself rather than the outer edges. 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 of a gloved hand on the edges of the film, which is mounted on

864-402: The increased popularity of Super 16 film, most 16 mm stock manufactured today is single perf unless requested otherwise. Some obsolete formats such as 9.5 mm film and some variants of 17.5 mm film 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

900-506: The magnetic stripes. These perfs are commonly referred to as CinemaScope (CS) or "Fox hole" perforations, or simply "Foxholes" (because, initially, all CinemaScope films were made by 20th Century Fox ). 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

936-512: The middle after development. Super 8 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. All of the systems described above place the perforations down either one side (Standard and Super 8, Super 16 ) 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

972-545: The moving picture camera of William Friese-Greene . These former Edison associates helped to design the Eidoloscope projector system and a widescreen camera to film with, which would be used in the first commercial movie screening in world history on 20 May 1895. But Dickson soon parted company with them, to become part of the group that formed the American Mutoscope and Biograph Company , returning permanently to work in

1008-520: The sprocket wheel that engaged the strip was driven by an escapement disc mechanism—the first practical system for the high-speed stop-and-go film movement that would be the foundation for the next century of cinematography . In late 1894 or early 1895, William Dickson became an ad hoc advisor to the motion picture operation of the Latham brothers, Otway and Grey, who ran one of the leading Kinetoscope exhibition companies, and their father, Woodville Latham who had lectured in science. Seeking to develop

1044-412: Was a peep show machine showing a continuous loop of film, lit by a small lamp, viewed individually through the window of a cabinet housing its components. William Dickson and his team created the illusion of movement by continuously moving the strip of perforated film , bearing sequential images, whilst illuminating it by brief flashes of light through the slit in a rotating shutter . They also devised

1080-539: Was born on 3 August 1860 in Le Minihic-sur-Rance , Brittany, France. His mother, Elizabeth Kennedy-Laurie (1823–1879) was American, born in Virginia . His father was James Waite Dickson, a Scottish artist, astronomer and linguist. James Dickson claimed direct lineage from the painter William Hogarth , and from Judge John Waite, the man who sentenced King Charles I to death. At age 19 in 1879, William Dickson wrote

1116-503: Was designed to account for a size difference between its (processed) input and (unprocessed) output. When cellulose acetate film was developed, which does not shrink, two forms were produced for compatibility with existing equipment. Additionally, for 35 mm film only, there are several different shapes for these perforations. BH ( Bell and Howell ) perforations are used on camera negative film and have straight tops and bottoms with outward curving sides; they have been in use since

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1152-640: 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" (1.85 mm). This gave it longer projection life and also improved registration. One of its primary applications was usage in Technicolor 's dye imbibition printing (dye transfer). The DH perf never caught on, and Kodak's introduction of monopack Eastmancolor film in

1188-400: Was reduced to 0.01 mm in 1989, which allowed 16 mm camera manufacturers to slightly enlarge their registration pins and thus improve image registration and steadiness tolerances to less than 1/750th of the image height of the 16 mm frame. Standard 8 mm film uses 16 mm film that is perforated twice as frequently (half the pitch of normal 16 mm) and then split down

1224-546: Was the first to use the Kinetophone , the first device used in the earliest sound films . Film perforations Film perforations , also known as perfs and sprocket holes , are the holes placed in the film stock during manufacturing and used for transporting (by sprockets and claws) and steadying (by pin registration ) the film . Films may have different types of perforations depending on film gauge , film format , and intended usage. Perforations are also used as

1260-409: Was used as a secondary "shop standard" at Paramount and Universal 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, conventional 35 mm magnetic film

1296-546: Was used. 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. 17.5 mm film, in this context, is for magnetic sound elements only, and only for very cost-conscious producers. 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

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