A projectionist is a person who operates a movie projector , particularly as an employee of a movie theater . Projectionists are also known as "operators".
87-511: N.B. The dates given in the subject headings are approximate. The need for professional projectionists arose from the commercial showing of movie films to the general public in buildings specifically designed for the purpose or using variety theatres as part of the "bill", which began towards the end of the first decade of the twentieth century. Before the emergence of purpose-built movie theaters, film projectors in venues such as fairgrounds , music halls and Nickelodeons were usually operated by
174-406: A photographic film . This was used commercially as "celluloid", a highly flammable plastic that until the mid-20th century formed the basis for lacquers and photographic film. On May 2, 1887, Hannibal Goodwin filed a patent for "a photographic pellicle and process of producing same ... especially in connection with roller cameras", but the patent was not granted until September 13, 1898. In
261-584: A broken heating pipe at the Cleveland Clinic in Ohio . That tragedy claimed 123 lives during the fire and additional fatalities several days later, when hospitalized victims died due to inhaling excessive amounts of smoke from the burning film, which was laced with toxic gases such as sulfur dioxide and hydrogen cyanide . Related fires in other medical facilities prompted the growing disuse of nitrocellulose stock for X-rays by 1933, nearly two decades before its use
348-458: A cotton apron, and wiped it up. He hung the apron on the stove door to dry, and as soon as it was dry, a flash occurred as the apron ignited. His preparation method was the first to be widely used. The method was to immerse one part of fine cotton in 15 parts of an equal blend of sulfuric acid and nitric acid. After two minutes, the cotton was removed and washed in cold water to set the esterification level and to remove all acid residue. The cotton
435-451: A feature film print and other supporting material such as advertisements and trailers) onto a long-play platter or tower device, programming automation systems and very basic equipment maintenance such as cleaning film path components and the routine replacement of life-limited parts. More extensive maintenance and repairs are carried out by technicians employed centrally by the parent company and who visit its theatres to conduct maintenance on
522-505: A feature-length film without interruption while the following reel is laced up, two projectors focused on the same screen were used, with the projectionist 'changing over' from one to the other at the end of each reel. 2,000 foot 'double' reels were gradually introduced from the early 1930s onwards (approximately 20 minutes at the standardized sound speed of 24 fps ). Until the conversion to sound, electric motors were relatively uncommon on 35mm theater projectors: most were hand-cranked by
609-565: A few years, it is likely that projectionists, in the traditional sense of the word, will only be found in the small number of arthouse, cinematheque and repertory theatres that will continue to show film prints from archival collections . In May 2013, the BBC reported that by October 2013, "there will be no cinemas left in this country projecting 35mm". A projectionist in a modern theater in North America or Europe will typically carry out some or all of
696-407: A flame. For this reason, immersing burning film in water may not extinguish it, and could actually increase the amount of smoke produced. Owing to public safety precautions, London Underground forbade transport of movies on its system until well past the introduction of safety film. Cinema fires caused by the ignition of nitrocellulose film stock commonly occurred as well. In Ireland in 1926, it
783-422: A hard finish with a deep lustre. It is normally the first coat applied, then it is sanded and followed by other coatings that bond to it. Nail polish contains nitrocellulose, as it is inexpensive, dries quickly to a hard film, and does not damage skin. The explosive applications are diverse and nitrate content is typically higher for propellant applications than for coatings. For space flight, nitrocellulose
870-524: A nitrate base in the west, but rumors exist of 16 mm nitrate film having been produced in the former Soviet Union and China. Nitrate dominated the market for professional-use 35 mm motion picture film from the industry's origins to the early 1950s. While cellulose acetate-based safety film, notably cellulose diacetate and cellulose acetate propionate, was produced in the gauge for small-scale use in niche applications (such as printing advertisements and other short films to enable them to be sent through
957-653: A number of reasons including environmental regulation and the cost of application vs. "poly" finishes. However, Gibson still use nitrocellulose lacquers on all of their guitars, as well as Fender when reproducing historically accurate guitars. The nitrocellulose lacquer yellows and cracks over time, and custom shops will reproduce this aging to make instruments appear vintage. Guitars made by smaller shops (luthiers) also often use "nitro" as it has an almost mythical status among guitarists. Because of its explosive nature, not all applications of nitrocellulose were successful. In 1869, with elephants having been poached to near extinction,
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#17330851612631044-523: A projectile driver, it had around six times the gas generation of an equal volume of black powder and produced less smoke and less heating. Artillery shells filled with gun cotton were widely used during the American Civil War , and its use was one of the reasons the conflict was seen as the "first modern war." In combination with breech-loading artillery , such high explosive shells could cause greater damage than previous solid cannonballs. During
1131-428: A projectionist in a public movie theater was, and to some extent still is, regulated, to varying degrees in different jurisdictions. Some required projectionists to be licensed by local or central government, and this process sometimes required projectionists to undergo assessments or sit exams. Trade union-based regulation of the profession was also widespread in some jurisdictions, in which the licensing of projectionists
1218-421: A regular cycle. In smaller chains and independent theaters, and especially those situated in geographically remote locations, projectionists are more likely to undertake more extensive maintenance and repair duties, both on a theater's projection and sound equipment and on other infrastructure in the building, e.g. heating and air conditioning plant. 35mm release prints continue to be shipped on 2,000 foot reels to
1305-437: A showman or presenter, in the same way as a lanternist . The light source for most projectors in the early period was limelight , which did not require an electricity supply. Between approximately 1905 and 1915, two factors combined to transform the role of the projectionist into a separate job with a specific profile of skills and training. Concerns over the flammability of nitrate film , following several major fires during
1392-454: A significant scale from approximately 2006 to 2008, is rapidly bringing to an end the role of the projectionist as a professionally skilled operator of film-based projection equipment in mainstream theatres. As of November 2010, the major chains in the US and Europe are in the process of a large-scale conversion to digital projection, in some ways comparable to the mass installation of sound equipment in
1479-431: Is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid . One of its first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. It was also used to replace gunpowder as a low-order explosive in mining and other applications. In the form of collodion it was also a critical component in an early photographic emulsion,
1566-465: Is featured in E. B. White's Charlotte's Web . Nitrocellulose#Replacement filmstocks ( C 6 H 8 (NO 2 ) 2 O 5 ) n (dinitrocellulose) ( C 6 H 7 (NO 2 ) 3 O 5 ) n (trinitrocellulose, pictured in structures above) Nitrocellulose (also known as cellulose nitrate , flash paper , flash cotton , guncotton , pyroxylin and flash string , depending on form)
1653-453: Is for the production of lacquers and coatings, explosives, and celluloid . In terms of lacquers and coatings, nitrocellulose dissolves readily in organic solvents, which upon evaporation leave a colorless, transparent, flexible film. Nitrocellulose lacquers have been used as a finish on furniture and musical instruments. Guncotton, dissolved at about 25% in acetone , forms a lacquer used in preliminary stages of wood finishing to develop
1740-431: Is less prone to stretching than other available plastics. By the late 1990s, polyester had almost entirely superseded triacetate for the production of intermediate elements and release prints. Triacetate remains in use for most camera negative stocks because it can be "invisibly" spliced using solvents during negative assembly, while polyester film is usually spliced using adhesive tape patches, which leave visible marks in
1827-435: Is much more resistant to polymer degradation than either nitrate or triacetate. Although triacetate does not decompose in as dangerous a way as nitrate does, it is still subject to a process known as deacetylation, often nicknamed "vinegar syndrome" (due to the acetic acid smell of decomposing film) by archivists, which causes the film to shrink, deform, become brittle and eventually unusable. PET, like cellulose mononitrate,
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#17330851612631914-434: Is not a nitro compound , but a nitrate ester . The glucose repeat unit (anhydroglucose) within the cellulose chain has three OH groups, each of which can form a nitrate ester. Thus, nitrocellulose can denote mononitrocellulose , dinitrocellulose , and trinitrocellulose , or a mixture thereof. With fewer OH groups than the parent cellulose, nitrocelluloses do not aggregate by hydrogen bonding . The overarching consequence
2001-606: Is one of the largest fairs in India, where more than 60 million people gathered in January 2001, making it the largest gathering anywhere in the world. Kumbha means a pitcher and Mela means fair in Sanskrit. In the United States, fairs draw in as many as 150 million people each summer. Children's competitions at an American fair range from breeding small animals to robotics, whilst
2088-494: Is soluble in a mixture of ethanol and ether until nitrogen concentration exceeds 12%. Soluble nitrocellulose, or a solution thereof, is sometimes called collodion . Guncotton containing more than 13% nitrogen (sometimes called insoluble nitrocellulose) was prepared by prolonged exposure to hot, concentrated acids for limited use as a blasting explosive or for warheads of underwater weapons such as naval mines and torpedoes . Safe and sustained production of guncotton began at
2175-459: Is that the nitrocellulose is soluble in organic solvents such as acetone and esters; e.g., ethyl acetate , methyl acetate , ethyl carbonate . Most lacquers are prepared from the dinitrate, whereas explosives are mainly the trinitrate. The chemical equation for the formation of the trinitrate is The yields are about 85%, with losses attributed to complete oxidation of the cellulose to oxalic acid . The principal uses of cellulose nitrate
2262-401: Is unusual for these venues to have a total projectionist workforce of more than three or four. The job description of the projectionist began to vary considerably according to the type and location of theatre he or she worked in. In many of the multiplex theatre chains that emerged in the 1980s, the role of the projectionist was largely confined to assembling screening programs (consisting of
2349-505: The Champagne fairs in northern France, which were spread over six towns for a total period of about six weeks, drawing goods and customers from much of Europe. The Frankfurt Book Fair in Germany, still the largest trade fair for the publishing industry, began in the 12th century as a fair for manuscript books. Fairs were usually tied to special Christian feast days , such as the day of
2436-718: The Edison Company at another location on December 9, at its film-processing complex in West Orange, New Jersey . That catastrophic fire started inside a film-inspection building and caused over $ 7,000,000 in property damages ($ 213,000,000 today). Even after film technology changed, archives of older films remained vulnerable; the 1965 MGM vault fire burned many films that were decades old. The use of volatile nitrocellulose film for motion pictures led many cinemas to fireproof their projection rooms with wall coverings made of asbestos . Those additions intended to prevent or at least delay
2523-590: The Paris Exhibition of 1889 . Commercial production started in 1891, but the result was flammable and more expensive than cellulose acetate or cuprammonium rayon. Because of this predicament, production ceased early in the 1900s. Nitrocellulose was briefly known as "mother-in-law silk". Frank Hastings Griffin invented the double-godet, a special stretch-spinning process that changed artificial silk to rayon, rendering it usable in many industrial products such as tire cords and clothing. Nathan Rosenstein invented
2610-560: The Waltham Abbey Royal Gunpowder Mills in the 1860s, and the material rapidly became the dominant explosive, becoming the standard for military warheads, although it remained too potent to be used as a propellant. More-stable and slower-burning collodion mixtures were eventually prepared using less concentrated acids at lower temperatures for smokeless powder in firearms . The first practical smokeless powder made from nitrocellulose, for firearms and artillery ammunition,
2697-478: The billiards industry offered a US$ 10,000 prize to whoever came up with the best replacement for ivory billiard balls . John Wesley Hyatt created the winning replacement, which he created with a new material he invented, called camphored nitrocellulose—the first thermoplastic , better known as celluloid . The invention enjoyed a brief popularity, but the Hyatt balls were extremely flammable, and sometimes portions of
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2784-461: The "spunize process" by which he turned rayon from a hard fiber to a fabric. This allowed rayon to become a popular raw material in textiles. Nitrocellulose lacquer manufactured by (among others) DuPont , was the primary material for painting automobiles for many years. Durability of finish, complexities of "multiple stage" modern finishes, and other factors including environmental regulation led manufacturers to choose newer technologies. It remained
2871-638: The Bronx. On May 13, a fire at Universal Pictures ' Colonial Hall "film factory" in Manhattan consumed another extensive collection. Yet again, on June 13 in Philadelphia, a fire and a series of explosions ignited inside the 186-square-meter (2,000-square-foot) film vault of the Lubin Manufacturing Company and quickly wiped out virtually all of that studio's pre-1914 catalogue. Then a second fire hit
2958-630: The Roman provinces of Judea and Syria Palaestina , Jewish rabbis prohibited Jews from participating in fairs in certain towns because the religious nature of the fairs contravened the prescribed practice of Judaism . In the Middle Ages , many fairs developed as temporary markets and were especially important for long-distance and international trade , as wholesale traders travelled, sometimes for many days, to fairs where they could be sure to meet those they needed to buy from or sell to. The most famous were
3045-415: The budgets of many smaller theaters. In practice, though, this has not proved to be as much of a problem as was feared. Rather, with the increased use of automated long-play systems in cinemas, the greater strength of polyester has been a significant advantage in lessening the risk of a film performance being interrupted by a film break. Despite its self-oxidizing hazards, nitrate is still regarded highly as
3132-406: The chambering of the feed and takeup reels in thick metal covers with small slits to allow the film to run through them. The projector is additionally modified to accommodate several fire extinguishers with nozzles aimed at the film gate. The extinguishers automatically trigger if a piece of film near the gate starts to burn. While this triggering would likely damage or destroy a significant portion of
3219-521: The cinema's first decade resulted in the increasing regulation of film exhibition, including the requirement that projectors be housed in fireproof booths, segregated from the auditorium. In the United Kingdom, for example, this requirement was introduced in the Cinematograph Act 1909 , and effectively prevented the projectionist from also carrying out a public-facing role. The legal right to act as
3306-446: The classical "movie palace", the labour-intensive nature of changeovers, carbon arc lamps, and nitrate handling required large workforces of projectionists, with up to six or seven working in a single booth and a rigid management hierarchy within the profession being common. In contrast, the multiplexes of the 1980s and '90s were designed in such a way that a single projectionist can operate simultaneous screenings in 10-20 auditoria, and it
3393-439: The concentration of unreacted acid. In 1855, the first human-made plastic , nitrocellulose (branded Parkesine , patented in 1862), was created by Alexander Parkes from cellulose treated with nitric acid and a solvent. In 1868, American inventor John Wesley Hyatt developed a plastic material he named Celluloid , improving on Parkes' invention by plasticizing the nitrocellulose with camphor so that it could be processed into
3480-428: The early 20th century were lost through this accelerating, self-catalyzed disintegration or through studio warehouse fires, and many others were deliberately destroyed specifically to avoid the fire risk. Salvaging old films is a major problem for film archivists (see film preservation ). Nitrocellulose film base manufactured by Kodak can be identified by the presence of the word "nitrate" in dark letters along one edge;
3567-519: The early to mid 20th century for destroying or heavily damaging cinemas, inflicting many serious injuries and deaths, and for reducing to ashes the master negatives and original prints of tens of thousands of screen titles, turning many of them into lost films . Even when nitrate stock did not start the blaze, flames from other sources spread to large nearby film collections, producing intense and highly destructive fires. In 1914—the same year that Goodwin Film
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3654-518: The fairground. These courts were called a pye powder court (from Old French pieds pouldres , literally "dusty feet", meaning an itinerant trader, from Medieval Latin pedes pulverosi ). The chaotic nature of the Stagshaw Bank Fair with masses of people and animals and stalls inspired the Newcastle colloquialism "like a Stagey Bank Fair" to describe a general mess. The American county fair
3741-433: The favorite of hobbyists for both historical reasons and for the ease with which a professional finish can be obtained. Most automobile "touch up" paints are still made from lacquer because of its fast drying, easy application, and superior adhesion properties – regardless of the material used for the original finish. Guitars sometimes shared color codes with current automobiles. It fell out of favor for mass production use for
3828-417: The first World War , British authorities were slow to introduce grenades, with soldiers at the front improvising by filling ration tin cans with gun cotton , scrap and a basic fuse. Further research indicated the importance of washing the acidified cotton. Unwashed nitrocellulose (sometimes called pyrocellulose) may spontaneously ignite and explode at room temperature , as the evaporation of water results in
3915-429: The first time. Multiple channel audio systems using magnetic sound and 70mm film prints were also introduced in the 1950s, and these required specialist projection skills to handle. Like nitrate film prints, xenon arc bulbs require special safety precautions: if handled incorrectly they can explode, causing serious injury to the projectionist. Staffing levels in projection booths decreased rapidly during this period. In
4002-598: The following duties. Funfair A fair (archaic: faire or fayre ) is a gathering of people for a variety of entertainment or commercial activities. Fairs are typically temporary with scheduled times lasting from an afternoon to several weeks. Fairs showcase a wide range of goods, products, and services, and often include competitions, exhibitions, and educational activities. Fairs can be thematic, focusing on specific industries or interests. Variations of fairs include: The Roman fairs were holidays on which work and business such as law courts were suspended. In
4089-462: The frame area. However, ultrasonic splicing in the frame line area can be invisible. Also, polyester film is so strong, it will not break under tension and may cause serious damage to expensive camera or projector mechanisms in the event of a film jam, whereas triacetate film breaks easily, reducing the risk of damage. Many were opposed to the use of polyester for release prints for this reason, and because ultrasonic splicers are very expensive, beyond
4176-626: The job title "Booth Usher" for an employee who simply carries out basic screening operations and does not perform any program assembly, maintenance or repair procedures. Their starting wage is the same as that for popcorn concessionists and ushers ($ 7.84 per hour in Ohio as of August 2009). Smaller theaters in this chain and those with union bargaining contracts that specify a minimum wage utilize management for these duties. In Britain, this started to happen early 2000 onward as labour laws were wiped out by then. The introduction of digital cinema projection , on
4263-620: The landing. Collodion, a solution of nitrocellulose, is used today in topical skin applications, such as liquid skin and in the application of salicylic acid , the active ingredient in Compound W wart remover. In 1832 Henri Braconnot discovered that nitric acid, when combined with starch or wood fibers, would produce a lightweight combustible explosive material, which he named xyloïdine . A few years later in 1838, another French chemist, Théophile-Jules Pelouze (teacher of Ascanio Sobrero and Alfred Nobel ), treated paper and cardboard in
4350-470: The late 1920s and early 1930s. This has essentially been made possible by the virtual print fee model of financing the equipment and installation costs, in which studios and equipment manufacturers provide equipment to theatres on a hire-purchase basis. The basic operation of digital cinema servers and projectors requires little more than routine IT skills and can be performed by a theatre's front-of-house and managerial staff with minimal extra training. Within
4437-419: The launch of cellulose triacetate base film by Eastman Kodak in 1948. Cellulose triacetate superseded nitrate as the film industry's mainstay base very quickly. While Kodak had discontinued some nitrate film stocks earlier, it stopped producing various nitrate roll films in 1950 and ceased production of nitrate 35 mm motion picture film in 1951. The crucial advantage cellulose triacetate had over nitrate
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#17330851612634524-454: The mails without the need for fire safety precautions), the early generations of safety film base had two major disadvantages relative to nitrate: it was much more expensive to manufacture, and considerably less durable in repeated projection. The cost of the safety precautions associated with the use of nitrate was significantly lower than the cost of using any of the safety bases available before 1948. These drawbacks were eventually overcome with
4611-423: The main or only event that took place in a purpose-built theater, rather than incorporated into other forms of live entertainment, the role of the projectionist became more specialised and began to incorporate elements of showmanship once again. The safety precautions associated with nitrate required 35mm film prints to be shipped in reels no longer than 1,000 feet (approximately 15 minutes at 16 fps ). In order show
4698-502: The manufacture of guncotton were obtained by John Hall & Son in 1846, and industrial manufacture of the explosive began at a purpose-built factory at Marsh Works in Faversham, Kent , a year later. The manufacturing process was not properly understood and few safety measures were put in place. A serious explosion in July that killed almost two dozen workers resulted in the immediate closure of
4785-448: The meantime, George Eastman had already started production of roll-film using his own process. Nitrocellulose was used as the first flexible film base , beginning with Eastman Kodak products in August 1889. Camphor is used as a plasticizer for nitrocellulose film, often called nitrate film. Goodwin's patent was sold to Ansco , which successfully sued Eastman Kodak for infringement of
4872-455: The migration of flames beyond the projection areas. A training film for projectionists included footage of a controlled ignition of a reel of nitrate film, which continued to burn even when fully submerged in water. Once burning, it is extremely difficult to extinguish. Unlike most other flammable materials, nitrocellulose does not need a source of air to continue burning, since it contains sufficient oxygen within its molecular structure to sustain
4959-453: The organizations National FFA Organization & 4-H have become the traditional associations. The Sirsi Marikamba Devi Fair of the deity is held every alternate year in the month of March and taken through the city Sirsi, Karnataka . It is attended by a very large number of devotees. It is also most famous and biggest fair (Jaatre) of the India. Devotees from all around the state participate in this enormous event indulging themselves in
5046-465: The outer shell would explode upon impact. An owner of a billiard saloon in Colorado wrote to Hyatt about the explosive tendencies, saying that he did not mind very much personally but for the fact that every man in his saloon immediately pulled a gun at the sound. The process used by Hyatt to manufacture the billiard balls, patented in 1881, involved placing the mass of nitrocellulose in a rubber bag, which
5133-399: The patent and was awarded $ 5,000,000 in 1914 to Goodwin Film. Disastrous fires related to celluloid or "nitrate film" became regular occurrences in the motion picture industry throughout the silent era and for many years after the arrival of sound film . Projector fires and spontaneous combustion of nitrate footage stored in studio vaults and in other structures were often blamed during
5220-530: The plant. Guncotton manufacture ceased for over 15 years until a safer procedure could be developed. The British chemist Frederick Augustus Abel developed the first safe process for guncotton manufacture, which he patented in 1865. The washing and drying times of the nitrocellulose were both extended to 48 hours and repeated eight times over. The acid mixture was changed to two parts sulfuric acid to one part nitric. Nitration can be controlled by adjusting acid concentrations and reaction temperature. Nitrocellulose
5307-414: The presence of a bishop, sheriff or governor. Later various benefits were granted to specific fairs, such as the granting of a holiday status to a fair or protections against arrest for specific laws for the duration of the fair. Officials were authorised to mete out justice to those who attended their fair; this led to even the smallest fair having a court to adjudicate on offences and disputes arising within
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#17330851612635394-501: The present day, even though very few theaters still present films using a two-projector system with changeovers. A number of attempts have been made over the years to introduce larger shipping reels for print distribution, but none has gained widespread acceptance. Some larger theater chains are now in the process of eliminating the projectionist's job altogether. In order to avoid paying a higher wage rate and to circumvent skilled labor laws, some companies (such as Cinemark Theaters) use
5481-459: The procession. Amusements for children, circuses, variety of shops, dramas and plays and many such things are set up for the people. It depicts the story of the goddess killing Mahishasura . Fairs attracted great numbers of people and they often resulted in public order issues and sometimes riots. The holding of fairs was, therefore, granted by royal charter . Initially they were only allowed in towns and places where order could be maintained due to
5568-426: The projectionist. Contemporary accounts suggest that hand cranking at a consistent speed took a considerable amount of skill. Presentation technique also began to include tasks such as operating auditorium lighting systems [dimmers], curtains [side-tabs] and masking systems and lantern slide projectors. During the 1920s, movie theaters became larger and projection equipment had to adapt to this. Limelight illumination
5655-528: The projector's components, it would contain a fire and prevent far greater damage. Projection rooms may also be required to have automatic metal covers for the projection windows, preventing the spread of fire to the auditorium . Today, the Dryden Theatre at the George Eastman Museum is one of a few theaters in the world that is capable of safely projecting nitrate films and regularly screens them to
5742-540: The public. The BFI Southbank in London is the only cinema in the United Kingdom licensed to show Nitrate Film. The use of nitrate film and its fiery potential were certainly not issues limited to the realm of motion pictures or to commercial still photography. The film was also used for many years in medicine, where its hazardous nature was most acute, especially in its application to X-ray photography. In 1929, several tons of stored X-ray film were ignited by steam from
5829-678: The reels of a feature presentation to be joined together into a single roll, in some cases up to 30,000 feet (approx. six hours at 24fps) in length; and the xenon arc lamp , which can burn continuously and unattended for as long as is needed (most carbon arc lamphouses will run for a maximum of 40–50 minutes before the carbon rod needs replacing, and require regular adjustment by the projectionist during that time). Automation systems were also introduced, which could be programmed in advance of each screening to perform functions such as operating auditorium lighting, adjusting volume levels and changing audio formats. Some would argue that these technologies reduced
5916-434: The requirement that projectionists should be formally trained to handle them to ensure public safety. But the formal training and licensing of projectionists continued in most of the US and Europe well after nitrate had been superseded in the 1950s, and in a minority of jurisdictions it still continues. With the advent of feature-length films during the early to mid-teens and the increasing tendency for film screenings to be
6003-476: The restrictions on reel lengths previously necessitated by the fire risk, with the result that systems were developed to enable the projection of a complete feature film using a single, unattended projector. Two essential technologies were needed to enable this: the long-play device, a.k.a. platter, i.e. a turntable 4–6 feet in diameter or (in the case of Sword Systems and Sabre Systems by EPRAD) an extremely large film reel 3–5 feet in diameter either of which enabled
6090-533: The role of the projectionist, changed fundamentally over an extended period between the early 1950s and late 1960s. Nitrate film was superseded by cellulose triacetate for release prints in the US and Europe over about a five-year period following the stock's commercial launch in October 1948 (though older nitrate prints remained in circulation for quite a long time afterwards and are still occasionally utilized in licensed cinemas for special screenings). With nitrate went
6177-486: The saint of the local church. Stagshaw in England, is documented to have held annual fairs as early as 1293 consisting of the sales of animals. Along with the main fair held on 4 July, the city also hosted smaller fairs throughout the year where specific types of animals were sold, such as one for horses, one for lambs, and one for ewes. The Kumbh Mela , held every twelve years, at Allahabad , Haridwar , Nashik , and Ujjain
6264-455: The same way. Jean-Baptiste Dumas obtained a similar material, which he called nitramidine . Around 1846 Christian Friedrich Schönbein , a German-Swiss chemist, discovered a more practical formulation. As he was working in the kitchen of his home in Basel , he spilled a mixture of nitric acid (HNO 3 ) and sulfuric acid (H 2 SO 4 ) on the kitchen table. He reached for the nearest cloth,
6351-432: The skill level or downgraded the showmanship element of the projectionist's job (for example, by eliminating the need for changeovers and nitrate handling precautions). Others would argue that more advanced skills were needed in other areas. With the introduction of widescreen in the early 1950s, projectionists had to cope with the additional lenses, aperture plates and masking systems needed for different aspect ratios for
6438-446: The stock is more transparent than replacement stocks, and older films used denser silver in the emulsion. The combination results in a notably more luminous image with a high contrast ratio. The solubility of nitrocellulose was the basis for the first " artificial silk " by Georges Audemars in 1855, which he called " Rayon ". . However, Hilaire de Chardonnet was the first to patent a nitrocellulose fiber marketed as "artificial silk" at
6525-416: The use of which revolutionized photography in the 1860s. In the 20th century it was adapted to automobile lacquer and adhesives . The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. The quality of the cellulose is important. Hemicellulose , lignin , pentosans , and mineral salts give inferior nitrocelluloses. In precise chemical terms, nitrocellulose
6612-489: The word only in clear letters on a dark background indicates derivation from a nitrate base original negative or projection print, but the film in hand itself may be a later print or copy negative, made on safety film. Acetate film manufactured during the era when nitrate films were still in use was marked "Safety" or "Safety Film" along one edge in dark letters. 8 , 9.5 , and 16 mm film stocks, intended for amateur and other nontheatrical use, were never manufactured with
6699-684: Was awarded $ 5,000,000 from Kodak for patent infringement—nitrate film fires incinerated a significant portion of the United States' early cinematic history. In that year alone, five very destructive fires occurred at four major studios and a film-processing plant. Millions of feet of film burned on March 19 at the Eclair Moving Picture Company in Fort Lee, New Jersey . Later that same month, many more reels and film cans of negatives and prints also burned at Edison Studios in New York City, in
6786-659: Was blamed for the Dromcolliher cinema tragedy in County Limerick in which 48 people died. Then in 1929 at the Glen Cinema in Paisley, Scotland , a film-related fire killed 69 children. Today, nitrate film projection is rare and normally highly regulated and requires extensive precautions, including extra health-and-safety training for projectionists. A special projector certified to run nitrate films has many modifications, among them
6873-408: Was discontinued for motion-picture films in favour of cellulose acetate film , more commonly known as "safety film". Nitrocellulose was found to gradually decompose, releasing nitric acid and further catalyzing the decomposition (eventually into a flammable powder). Decades later, storage at low temperatures was discovered as a means of delaying these reactions indefinitely. Many films produced during
6960-470: Was incorporated into collective bargaining agreements between employers and unions. In the United States, projectionists were sometimes 'pooled out' to theatre companies via their union. Closed shop working by projectionists was common in British cinema chains until the early 1980s. The original reason for this regulation was the necessity for safety precautions for the screening of nitrate prints , and hence
7047-607: Was invented by French chemist Paul Vieille in 1884. Jules Verne viewed the development of guncotton with optimism. He referred to the substance several times in his novels. His adventurers carried firearms employing this substance. In his From the Earth to the Moon , guncotton was used to launch a projectile into space. Because of their fluffy and nearly white appearance, nitrocellulose products are often referred to as cottons, e.g. lacquer cotton, celluloid cotton, and gun cotton. Guncotton
7134-441: Was originally made from cotton (as the source of cellulose) but contemporary methods use highly processed cellulose from wood pulp . While guncotton is dangerous to store, the hazards it presents can be minimized by storing it dampened with various liquids, such as alcohol. For this reason, accounts of guncotton usage dating from the early 20th century refer to "wet guncotton." The power of guncotton made it suitable for blasting. As
7221-425: Was replaced by the electrically powered carbon arc lamp, and with the arrival of sound electric motors were installed to drive projectors (a more constant speed was required for sound playback than could be achieved by hand cranking). The operation and basic maintenance of audio equipment also became part of the projectionist's job following the introduction of sound. The technology of cinema projection, and with it
7308-425: Was that it was no more of a fire risk than paper (the stock is often referred to as "non-flam": this is true—but it is combustible, just not in as volatile or as dangerous a way as nitrate), while it almost matched the cost and durability of nitrate. It remained in almost exclusive use in all film gauges until the 1980s, when polyester / PET film began to supersede it for intermediate and release printing. Polyester
7395-438: Was then placed in a cylinder of liquid and heated. Pressure was applied to the liquid in the cylinder, which resulted in a uniform compression on the nitrocellulose mass, compressing it into a uniform sphere as the heat vaporized the solvents. The ball was then cooled and turned to make a uniform sphere. In light of the explosive results, this process was called the "Hyatt gun method". An overheated container of dry nitrocellulose
7482-545: Was then slowly dried at a temperature below 40 °C (104 °F). Schönbein collaborated with the Frankfurt professor Rudolf Christian Böttger , who had discovered the process independently in the same year. By coincidence, a third chemist, the Brunswick professor F. J. Otto had also produced guncotton in 1846 and was the first to publish the process, much to the disappointment of Schönbein and Böttger. The patent rights for
7569-480: Was used by Copenhagen Suborbitals on several missions as a means of jettisoning components of the rocket/space capsule and deploying recovery systems. However, after several missions and flights, it proved not to have the desired explosive properties in a near vacuum environment. In 2014, the Philae comet lander failed to deploy its harpoons because its 0.3 grams of nitrocellulose propulsion charges failed to fire during
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