35 mm film (millimeter) is the film gauge most commonly used for motion pictures and chemical still photography (see 135 film). The name of the gauge refers to the width of the photographic film, which consists of strips 34.98 ±0.03 mm (1.377 ±0.001 inches) wide.[fn 1] The standard negative pulldown for movies ("single-frame" format) is four perforations per frame along both edges, which results in 16 frames per foot of film. For still photography, the standard frame has eight perforations on each side.
A variety of largely proprietary gauges were devised for the numerous camera and projection systems being developed independently in the late 19th century and early 20th century, ranging from 13 to 75 mm (0.51 to 2.95 in), as well as a variety of film feeding systems. This resulted in cameras, projectors, and other equipment having to be calibrated to each gauge. The 35 mm width, originally specified as 1 3⁄8 inches, was introduced in 1892 by William Dickson and Thomas Edison, using 120 film stock supplied by George Eastman.[fn 1] Film 35 mm wide with four perforations per frame became accepted as the international standard gauge in 1909, and remained by far the dominant film gauge for image origination and projection until the advent of digital photography and cinematography, despite challenges from smaller and larger gauges, because its size allowed for a relatively good trade-off between the cost of the film stock and the quality of the images captured.
The gauge has been versatile in application. It has been modified to include sound, redesigned to create a safer film base, formulated to capture color, has accommodated a bevy of widescreen formats, and has incorporated digital sound data into nearly all of its non-frame areas. Eastman Kodak, Fujifilm and Agfa-Gevaert are some companies that offered 35 mm films. Today Kodak is the last remaining manufacturer of motion picture film. In October 2018, Kodak announced their licensing agreement with AMB Media LLC to launch the KODAK Digitizing Box. This service allows Kodak formats to be digitized to digital formats. 
The ubiquity of 35 mm movie projectors in commercial movie theaters made 35 mm the only motion picture format that could be played in almost any cinema in the world, until digital projection largely superseded it in the 21st century. It is difficult to compare the quality of film to digital media, but a good estimate would be about 33.6 megapixels (67.2 megapixels DSLR Bayer equivalent) would equal one 35-millimeter high quality color frame of film.
In 1880, George Eastman began to manufacture gelatin dry photographic plates in Rochester, New York. Along with W. H. Walker, Eastman invented a holder for a roll of picture-carrying gelatin layer-coated paper. Hannibal Goodwin's invention of nitrocellulose film base in 1887 was the first transparent, flexible film. Eastman's was the first major company, however, to mass-produce these components, when in 1889 Eastman realized that the dry-gelatino-bromide emulsion could be coated onto this clear base, eliminating the paper.
With the advent of flexible film, Thomas Edison quickly set out on his invention, the Kinetoscope, which was first shown at the Brooklyn Institute of Arts and Sciences on 9 May 1893. The Kinetoscope was a film loop system intended for one-person viewing. Edison, along with assistant W. K. L. Dickson, followed that up with the Kinetophone, which combined the Kinetoscope with Edison's cylinder phonograph. Beginning in March 1892, Eastman and then, from April 1893 into 1896, New York's Blair Camera Co. supplied Edison with film stock. At first Blair would supply only 40 mm (1 9⁄16 in) film stock that would be trimmed and perforated at the Edison lab to create 1 3⁄8 in (34.925 mm) gauge filmstrips, then at some point in 1894 or 1895, Blair began sending stock to Edison that was cut exactly to specification. Edison's aperture defined a single frame of film at 4 perforations high. Edison claimed exclusive patent rights to his design of 35 mm motion picture film, with four sprocket holes per frame, forcing his only major filmmaking competitor, American Mutoscope & Biograph, to use a 68 mm film that used friction feed, not sprocket holes, to move the film through the camera. A court judgment in March 1902 invalidated Edison's claim, allowing any producer or distributor to use the Edison 35 mm film design without license. Filmmakers were already doing so in Britain and Europe, where Edison had failed to file patents.
At the time, film stock was usually supplied unperforated and punched by the filmmaker to their standards with perforation equipment. A variation developed by the Lumière Brothers used a single circular perforation on each side of the frame towards the middle of the horizontal axis. It was Edison's format, however, that became first the dominant standard and then the "official" standard of the newly formed Motion Picture Patents Company, a trust established by Edison, which agreed in 1909 to what would become the standard: 35 mm gauge, with Edison perforations and a 1.33:1 (4:3) aspect ratio.[fn 2] Scholar Paul C. Spehr describes the importance of these developments:
The early acceptance of 35 mm as a standard had momentous impact on the development and spread of cinema. The standard gauge made it possible for films to be shown in every country of the world… It provided a uniform, reliable and predictable format for production, distribution and exhibition of movies, facilitating the rapid spread and acceptance of the movies as a world-wide device for entertainment and communication.
The costly image-forming silver compounds in a film stock's emulsion meant from the start that 35 mm filmmaking was to be an expensive hobby with a high barrier to entry for the public at large. Furthermore, the nitrocellulose film base of all early film stock was highly flammable, creating considerable risk for those not accustomed to the precautions necessary in its handling. The cost of film stock was directly proportional to its surface area, so a smaller film gauge for amateur use was the obvious path to affordability. The downside was that smaller images were less sharp and detailed, and because less light could be put through them in the finished film the size of an acceptably bright projected image was also limited.
Birt Acres was the first to attempt an amateur format, creating Birtac in 1898 by slitting the film into 17.5 mm widths. By the early 1920s, several formats had successfully split the amateur home movies market away from 35 mm: 28 mm (1.1 in) (1912), 9.5 mm (0.37 in) (1922), 16 mm (0.63 in) (1923), and Pathe Rural, a 17.5 mm format designed for safety film (1926). Eastman Kodak's 16 mm format won the amateur market and is still widely in use today, mainly in the Super 16 variation, which remains popular with professional filmmakers. The 16 mm size was specifically chosen to prevent third-party slitting, as it was easy to create 17.5 mm stock from slitting 35 mm stock in two. It also was the first major format to be released with only fireproof cellulose diacetate (and later cellulose triacetate) "safety film" base. This amateur market would be further diversified by the introduction of 8 mm film (0.31 in) in 1932, intended for amateur filmmaking and "home movies". By law, 16 mm and 8 mm gauge stock (and 35 mm films intended for non-theatrical use) had to be manufactured on safety stock. The effect of these gauges was to essentially make the 35 mm gauge almost the exclusive province of professional filmmakers, a divide which mostly remains to this day.
Just as the format was recognized as a standard in 1909, still film cameras were developed that took advantage of the 35 mm format and allowed a large number of exposures for each length of film loaded into the camera. The frame size was increased to 24×36 mm. (This increase is on the same gauge since the stills are shot horizontally instead of vertically. 24 mm from perforation to perforation, 36 mm along an 8-perforation segment of the 35 mm film stock.) Although the first design was patented as early as 1908, the first commercial 35 mm camera was the 1913 Tourist Multiple, for movie and still photography, soon followed by the Simplex providing selection between full and half frame format. Oskar Barnack built his prototype Ur-Leica in 1913 and had it patented, but Ernst Leitz did not decide to produce it before 1924. The first Leica camera to be fully standardised was the Leica Standard of 1932.
Inside the photographic emulsion are millions of light-sensitive silver halide crystals. Each crystal is a compound of silver plus a halogen (such as bromine, iodine or chlorine) held together in a cubical arrangement by electrical attraction. When the crystal is struck with light, free-moving silver ions build up a small collection of uncharged atoms. These small bits of silver, too small to even be visible under a microscope, are the beginning of a latent image. Developing chemicals use the latent image specks to build up density, an accumulation of enough metallic silver to create a visible image.
The emulsion is attached to the film base with a transparent adhesive called the subbing layer. On the back of the base is a layer called the anti-halation backing, which usually contains absorber dyes or a thin layer of silver or carbon (called rem-jet on color negative stocks). Without this coating, light not absorbed by the emulsion and passing into the base would be partly reflected back at the outer surface of the base, re-exposing the emulsion in less focused form and thereby creating halos around bright points and edges in the image. The anti-halation backing can also serve to reduce static buildup, which could be a significant problem with early black-and-white films. The film, running through a motion picture camera at 12 inches (300 mm) (early silent speed) to 18 inches (460 mm) (sound speed) per second, could build up enough static electricity to cause sparks bright enough to record their own forms on the film; anti-halation backing solved this problem.
Color films have multiple layers of silver halide emulsion to separately record the red, green and blue thirds of the spectrum. For every silver halide grain there is a matching color coupler grain (except Kodachrome film, to which color couplers were added during processing). The top layer of emulsion is sensitive to blue; below it is a yellow filter layer to block blue light; and under that is a green-sensitive layer followed by a red-sensitive layer. Just as in black-and-white, the first step in color development converts exposed silver halide grains into metallic silver – except that an equal amount of color dye will be formed as well. The color couplers in the blue-sensitive layer will form yellow dye during processing, the green layer will form magenta dye and the red layer will form cyan dye. A bleach step will convert the metallic silver back into silver halide, which is then removed along with the unexposed silver halide in the fixer and wash steps, leaving only color dyes.
In the 1980s Eastman Kodak invented the T-Grain, a synthetically manufactured silver halide grain that had a larger, flat surface area and allowed for greater light sensitivity in a smaller, thinner grain. Thus Kodak could solve the problem of higher speed (greater light sensitivity—see film speed) which required larger grain and therefore more "grainy" images. With T-Grain technology, Kodak refined the grain structure of all their "EXR" line of motion picture film stocks (which was eventually incorporated into their "MAX" still stocks). Fuji films followed suit with their own grain innovation, the tabular grain in their SUFG (Super Unified Fine Grain) SuperF negative stocks, which are made up of thin hexagonal tabular grains.
Originally, film was a strip of cellulose nitrate coated with black-and-white photographic emulsion. Early film pioneers, like D. W. Griffith, color tinted or toned portions of their movies for dramatic impact, and by 1920, 80 to 90 percent of all films were tinted. The first successful natural color process was Britain's Kinemacolor (1908–1914), a two-color additive process that used a rotating disk with red and green filters in front of the camera lens and the projector lens. But any process that photographed and projected the colors sequentially was subject to color "fringing" around moving objects, and a general color flickering.
In 1916, William Van Doren Kelley began developing Prizma, the first commercially viable American color process using 35 mm film. Initially, like Kinemacolor, it photographed the color elements one after the other and projected the results by additive synthesis. Ultimately, Prizma was refined to bipack photography, with two strips of film, one treated to be sensitive to red and the other not, running through the camera face to face. Each negative was printed on one surface of the same duplitized print stock and each resulting series of black-and-white images was chemically toned to transform the silver into a monochrome color, either orange-red or blue-green, resulting in a two-sided, two-colored print that could be shown with any ordinary projector. This system of two-color bipack photography and two-sided prints was the basis for many later color processes, such as Multicolor, Brewster Color and Cinecolor.
Although it had been available previously, color in Hollywood feature films first became truly practical from the studios' commercial perspective with the advent of Technicolor, whose main advantage was quality prints in less time than its competitors. In its earliest incarnations, Technicolor was another two-color system that could reproduce a range of reds, muted bluish greens, pinks, browns, tans and grays, but not real blues or yellows. The Toll of the Sea, released in 1922, was the first film printed in their subtractive color system. Technicolor's camera photographed each pair of color-filtered frames simultaneously on one strip of black-and-white film by means of a beam splitter prism behind the camera lens. Two prints on half-thickness stock were made from the negative, one from only the red-filtered frames, the other from the green-filtered frames. After development, the silver images on the prints were chemically toned to convert them into images of the approximately complementary colors. The two strips were then cemented together back to back, forming a single strip similar to duplitized film.
In 1928, Technicolor started making their prints by the imbibition process, which was mechanical rather than photographic and allowed the color components to be combined on the same side of the film. Using two matrix films bearing hardened gelatin relief images, thicker where the image was darker, aniline color dyes were transferred into the gelatin coating on a third, blank strip of film.
Technicolor re-emerged as a three-color process for cartoons in 1932 and live action in 1934. Using a different arrangement of a beam-splitter cube and color filters behind the lens, the camera simultaneously exposed three individual strips of black-and-white film, each one recording one-third of the spectrum, which allowed virtually the entire spectrum of colors to be reproduced. A printing matrix with a hardened gelatin relief image was made from each negative, and the three matrices transferred color dyes into a blank film to create the print.
Two-color processes, however, were far from extinct. In 1934, William T. Crispinel and Alan M. Gundelfinger revived the Multicolor process under the company name Cinecolor. Cinecolor saw considerable use in animation and low-budget pictures, mainly because it cost much less than three-color Technicolor. If color design was carefully managed, the lack of colors such as true green could pass unnoticed. Although Cinecolor used the same duplitized stock as Prizma and Multicolor, it had the advantage that its printing and processing methods yielded larger quantities of finished film in less time.
In 1950 Kodak announced the first Eastman color 35 mm negative film (along with a complementary positive film) that could record all three primary colors on the same strip of film. An improved version in 1952 was quickly adopted by Hollywood, making the use of three-strip Technicolor cameras and bipack cameras (used in two-color systems such as Cinecolor) obsolete in color cinematography. This "monopack" structure is made up of three separate emulsion layers, one sensitive to red light, one to green and one to blue.
Although Eastman Kodak had first introduced acetate-based film, it was far too brittle and prone to shrinkage, so the dangerously flammable nitrate-based cellulose films were generally used for motion picture camera and print films. In 1949 Kodak began replacing all nitrocellulose (nitrate-based) films with the safer, more robust cellulose triacetate-based "Safety" films. In 1950 the Academy of Motion Picture Arts and Sciences awarded Kodak with a Scientific and Technical Academy Award (Oscar) for the safer triacetate stock. By 1952, all camera and projector films were triacetate-based. Most if not all film prints today are made from synthetic polyester safety base (which started replacing Triacetate film for prints in the early 1990s). The downside of polyester film is that it is extremely strong, and, in case of a fault, will stretch and not break–potentially causing damage to the projector and ruining a fairly large stretch of film: 2–3 ft or approximately 2 seconds. Also, polyester film will melt if exposed to the projector lamp for too long. Original camera negative is still made on a triacetate base, and some intermediate films (certainly including internegatives or "dupe" negatives, but not necessarily including interpositives or "master" positives) are also made on a triacetate base as such films must be spliced during the "negative assembly" process, and the extant negative assembly process is solvent-based. Polyester films are not compatible with solvent-based assembly processes.
Besides black & white and color negative films, there are black & white and color reversal films, which when developed create a positive ("natural") image that is projectable. There are also films sensitive to non-visible wavelengths of light, such as infrared.
In the conventional motion picture format, frames are four perforations tall, with an aspect ratio of 1.375:1, 22 by 16 mm (0.866 by 0.630 in). This is a derivation of the aspect ratio and frame size designated by Thomas Edison (24.89 mm by 18.67 mm or 0.980 in by 0.735 in) at the dawn of motion pictures, which was an aspect ratio of 1.33:1. The first sound features were released in 1926–27, and while Warner Bros. was using synchronized phonograph discs (sound-on-disc), Fox placed the soundtrack in an optical record directly on the film (sound-on-film) on a strip between the sprocket holes and the image frame. "Sound-on-film" was soon adopted by the other Hollywood studios, resulting in an almost square image ratio of 0.860 in by 0.820 in.
By 1929, most movie studios had revamped this format using their own house aperture plate size to try to recreate the older screen ratio of 1.33:1. Furthermore, every theater chain had their own house aperture plate size in which the picture was projected. These sizes often did not match up even between theaters and studios owned by the same company, and therefore, uneven projection practices occurred.
In November 1929, the Society of Motion Pictures Engineers set a standard aperture ratio of 0.800 in by 0.600 in. Known as the "1930 standard," studios which followed the suggested practice of marking their camera viewfinders for this ratio were: Paramount-Famous-Lasky, Metro-Goldwyn Mayer, United Artists, Pathe, Universal, RKO, Tiffany-Stahl, Mack Sennett, Darmour, and Educational. The Fox Studio markings were the same width but allowed .04 in more height.
In 1932, in refining this ratio, the Academy of Motion Picture Arts and Sciences expanded upon this 1930 standard. The camera aperture became 22 by 16 mm (0.87 by 0.63 in), and the projected image would use an aperture plate size of 0.825 by 0.600 in (21.0 by 15.2 mm), yielding an aspect ratio of 1.375:1. This became known as the "Academy" ratio, named so after them. Since the 1950s the aspect ratio of some theatrically released motion picture films has been 1.85:1 (1.66:1 in Europe) or 2.35:1 (2.40:1 after 1970). The image area for "TV transmission" is slightly smaller than the full "Academy" ratio at 21 by 16 mm (0.83 by 0.63 in), an aspect ratio of 1.33:1. Hence when the "Academy" ratio is referred to as having an aspect ratio of 1.33:1, it is done so mistakenly.
The commonly used anamorphic format uses a similar four-perf frame, but an anamorphic lens is used on the camera and projector to produce a wider image, today with an aspect ratio of about 2.39:1 (more commonly referred to as 2.40:1). The ratio was formerly 2.35:1—and is still often mistakenly referred to as such—until an SMPTE revision of projection standards in 1970). The image, as recorded on the negative and print, is horizontally compressed (squeezed) by a factor of 2.
The unexpected success of the Cinerama widescreen process in 1952 led to a boom in film format innovations to compete with the growing audiences of television and the dwindling audiences in movie theaters. These processes could give theatergoers an experience that television could not at that time—color, stereophonic sound and panoramic vision. Before the end of the year, 20th Century Fox had narrowly "won" a race to obtain an anamorphic optical system invented by Henri Chrétien, and soon began promoting the Cinemascope technology as early as the production phase.
Looking for a similar alternative, other major studios hit upon a simpler, less expensive solution by April 1953: the camera and projector used conventional spherical lenses (rather than much more expensive anamorphic lenses), but by using a removable aperture plate in the film projector gate, the top and bottom of the frame could be cropped to create a wider aspect ratio. Paramount Studios began this trend with their aspect ratio of 1.66:1, first used in Shane, which was originally shot for Academy ratio. It was Universal Studios, however, with their May release of Thunder Bay that introduced the now standard 1.85:1 format to American audiences and brought attention to the industry the capability and low cost of equipping theaters for this transition.
Other studios followed suit with aspect ratios of 1.75:1 up to 2:1. For a time, these various ratios were used by different studios in different productions, but by 1956, the aspect ratio of 1.85:1 became the "standard" US format. These flat films are photographed with the full Academy frame, but are matted (most often with a mask in the theater projector, not in the camera) to obtain the "wide" aspect ratio. The standard, in some European countries, became 1.66:1 instead of 1.85:1, although some productions with pre-determined American distributors composed for the latter to appeal to US markets.
In September 1953, 20th Century Fox debuted CinemaScope with their production of The Robe to great success. CinemaScope became the first marketable usage of an anamorphic widescreen process and became the basis for a host of "formats," usually suffixed with -scope, that were otherwise identical in specification, although sometimes inferior in optical quality. (Some developments, such as SuperScope and Techniscope, however, were truly entirely different formats.) By the early 1960s, however, Panavision would eventually solve many of the CinemaScope lenses' technical limitations with their own lenses, and by 1967, CinemaScope was replaced by Panavision and other third-party manufacturers.
The 1950s and 1960s saw many other novel processes using 35 mm, such as VistaVision, SuperScope, and Technirama, most of which ultimately became obsolete. VistaVision, however, would be revived decades later by Lucasfilm and other studios for special effects work, while a SuperScope variant became the predecessor to the modern Super 35 format that is popular today.
The concept behind Super 35 originated with the Tushinsky Brothers' SuperScope format, particularly the SuperScope 235 specification from 1956. In 1982, Joe Dunton revived the format for Dance Craze, and Technicolor soon marketed it under the name "Super Techniscope" before the industry settled on the name Super 35. The central driving idea behind the process is to return to shooting in the original silent "Edison" 1.33:1 full 4-perf negative area (24.89 mm by 18.67 mm or 0.980 in by 0.735 in), and then crop the frame either from the bottom or the center (like 1.85:1) to create a 2.40:1 aspect ratio (matching that of anamorphic lenses) with an area of 24 by 10 mm (0.94 by 0.39 in). Although this cropping may seem extreme, by expanding the negative area out perf-to-perf, Super 35 creates a 2.40:1 aspect ratio with an overall negative area of 240 square millimeters (0.372 sq in), only 9 mm2 (0.014 sq in) less than the 1.85:1 crop of the Academy frame (248.81 mm2 or 0.386 sq in). The cropped frame is then converted at the intermediate stage to a 4-perf anamorphically squeezed print compatible with the anamorphic projection standard. This allows an "anamorphic" frame to be captured with non-anamorphic lenses, which are much more common. Up to 2000, once the film was photographed in Super 35, an optical printer was used to anamorphose (squeeze) the image. This optical step reduced the overall quality of the image and made Super 35 a controversial subject among cinematographers, many who preferred the higher image quality and frame negative area of anamorphic photography (especially with regard to granularity). With the advent of Digital intermediates (DI) at the beginning of the 21st century, however, Super 35 photography has become even more popular, since everything could be done digitally, scanning the original 4-perf 1.33:1 (or 3-perf 1.78:1) picture and cropping it to the 2.39:1 frame already in-computer, without anamorphosing stages, and also without creating an additional optical generation with increased grain. This process of creating the aspect ratio in the computer allows the studios to perform all post-production and editing of the movie in its original aspect (1.33:1 or 1.78:1) and to then release the cropped version, while still having the original when necessary (for Pan & Scan, HDTV transmission, etc.).
The non-anamorphic widescreen ratios (most commonly 1.85:1) used in modern feature films makes inefficient use of the available image area on 35 mm film using the standard 4-perf pulldown; the height of a 1.85:1 frame occupying only 65% of the distance between the frames. It is clear, therefore, that a change to a 3-perf pulldown would allow for a 25% reduction in film consumption whilst still accommodating the full 1.85:1 frame. Ever since the introduction of these widescreen formats in the 1950s various film directors and cinematographers have argued in favour of the industry making such a change. The Canadian cinematographer Miklos Lente invented and patented a three-perforation pull down system which he called "Trilent 35" in 1975 though he was unable to persuade the industry to adopt it.
The idea was later taken up by the Swedish film-maker Rune Ericson who was a strong advocate for the 3-perf system. Ericson shot his 51st feature Pirates of the Lake in 1986 using two Panaflex cameras modified to 3-perf pulldown and suggested that the industry could change over completely over the course of ten-years. However, the movie industry did not make the change mainly because it would have required the modification of the thousands of existing 35 mm projectors in movie theaters all over the world. Whilst it would have been possible to shoot in 3-perf and then convert to standard 4-perf for release prints the extra complications this would cause and the additional optical printing stage required made this an unattractive option at the time for most film makers.
However, in television production, where compatibility with an installed base of 35 mm film projectors is unnecessary, the 3-perf format is sometimes used, giving—if used with Super 35—the 16:9 ratio used by HDTV and reducing film usage by 25 percent. Because of 3-perf's incompatibility with standard 4-perf equipment, it can utilize the whole negative area between the perforations (Super 35 mm film) without worrying about compatibility with existing equipment; the Super 35 image area includes what would be the soundtrack area in a standard print. All 3-perf negatives require optical or digital conversion to standard 4-perf if a film print is desired, though 3-perf can easily be transferred to video with little to no difficulty by modern telecine or film scanners. With digital intermediate now a standard process for feature film post-production, 3-perf is becoming increasingly popular for feature film productions which would otherwise be averse to an optical conversion stage.
The VistaVision motion picture format was created in 1954 by Paramount Pictures to create a finer-grained negative and print for flat widescreen films. Similar to still photography, the format uses a camera running 35 mm film horizontally instead of vertically through the camera, with frames that are eight perforations long, resulting in a wider aspect ratio of 1.5:1 and greater detail, as more of the negative area is used per frame. This format is unprojectable in standard theaters and requires an optical step to reduce the image into the standard 4-perf vertical 35 mm frame.
While the format was dormant by the early 1960s, the camera system was revived for visual effects by John Dykstra at Industrial Light and Magic, starting with Star Wars, as a way of reducing granularity in the optical printer by having increased original camera negative area at the point of image origination. Its usage has again declined since the dominance of computer-based visual effects, although it still sees limited utilization.
These two perforations have remained by far the most commonly used ones. BH perforations are also known as N (negative) and KS as P (positive). The Bell & Howell perf remains the standard for camera negative films because of its perforation dimensions in comparison to most printers, thus it can keep a steady image compared to other perforations.
During continuous contact printing, the raw stock and the negative are placed next to one another around the sprocket wheel of the printer. The negative, which is the closer of the two to the sprocket wheel (thus creating a slightly shorter path), must have a marginally shorter pitch between perforations (0.1866 in pitch); the raw stock has a long pitch (0.1870 in). While cellulose nitrate and cellulose diacetate stocks used to shrink during processing slightly enough to have this difference naturally occur, modern safety stocks do not shrink at the same rate, and therefore negative (and some intermediate) stocks are perforated at a pitch of 0.2% shorter than print stock.
Three different digital soundtrack systems for 35 mm cinema release prints were introduced during the 1990s. They are: Dolby Digital, which is stored between the perforations on the sound side; SDDS, stored in two redundant strips along the outside edges (beyond the perforations); and DTS, in which sound data is stored on separate compact discs synchronized by a timecode track on the film just to the right of the analog soundtrack and left of the frame. Because these soundtrack systems appear on different parts of the film, one movie can contain all of them, allowing broad distribution without regard for the sound system installed at individual theatres.
The analogue optical track technology has also changed: in the early years of the 21st century distributors changed to using cyan dye optical soundtracks instead of applicated tracks, which use environmentally unfriendly chemicals to retain a silver (black-and-white) soundtrack. Because traditional incandescent exciter lamps produce copious amounts of infra-red light, and cyan tracks do not absorb infra-red light, this change has required theaters to replace the incandescent exciter lamp with a complementary colored red LED or laser. These LED or laser exciters are backwards-compatible with older tracks. The film Anything Else (2003) was the first to be released with only cyan tracks.
To facilitate this changeover, intermediate prints known as "high magenta" prints were distributed. These prints used a silver plus dye soundtrack that were printed into the magenta dye layer. The advantage gained was an optical soundtrack, with low levels of sibilant (cross-modulation) distortion, on both types of sound heads.
The success of digitally projected 3D movies in the first two decades of the 21st century led to a demand from some theater owners to be able to show these movies in 3D without incurring the high capital cost of installing digital projection equipment. To satisfy that demand, a number of systems had been proposed for 3D systems based on 35 mm film by Technicolor, Panavision and others. These systems are improved version of the "over-under" stereo 3D prints first introduced in the 1960s.
To be attractive to exhibitors, these schemes offered 3D films that can be projected by a standard 35 mm cinema projector with minimal modification, and so they are based on the use of "over-under" film prints. In these prints a left-right pair of 2.39:1 non-anamorphic images are substituted for the one 2.39:1 anamorphic image of a 2D "scope" print. The frame dimensions are based on those of the Techniscope 2-perf camera format used in the 1960s and '70s. However, when used for 3D the left and right frames are pulled down together, thus the standard 4-perf pulldown is retained, minimising the need for modifications to the projector or to long-play systems. The linear speed of film through the projector and sound playback both remain exactly the same as in normal 2D operation.
The Technicolor system uses the polarisation of light to separate the left and right eye images and for this they rent to exhibitors a combination splitter-polarizer-lens assembly which can be fitted to a lens turret in the same manner as an anamorphic lens. In contrast, the Panavision system uses a spectral comb filter system, but their combination splitter-filter-lens is physically similar to the Technicolor assembly and can be used in the same way. No other modifications are required to the projector for either system, though for the Technicolor system a silver screen is necessary, as it would be with polarised-light digital 3D. Thus a programme can readily include both 2D and 3D segments with only the lens needing to be changed between them.
In June 2012 Panavision 3D systems for both 35 mm film and digital projection were withdrawn from the market by DVPO theatrical (who marketed these system on behalf of Panavision) citing "challenging global economic and 3D market conditions".
In transition period centered around 2005–2015, the rapid conversion of the cinema exhibition industry to digital projection has seen 35 mm film projectors removed from most of the projection rooms as they are replaced by digital projectors. By the mid-2010s, most of the theaters across the world have been converted to digital projection, while others are still running 35 mm projectors. In spite of the uptake in digital projectors installed in global cinemas, 35mm film remains in a niche market of enthusiasts and format lovers.
Technical specifications for 35 mm film are standardized by SMPTE.
35 mm spherical
Super 35 mm film
35 mm anamorphic
135 is photographic film in a film format used for still photography. It is a cartridge film with a film gauge of 35 mm (1.4 in), typically used for hand-held photography in 35 mm film cameras. Its engineering standard for the film is controlled by ISO 1007.The term 135 (ISO 1007) was introduced by Kodak in 1934 as a designation for the cassette for 35 mm film, specifically for still photography. It quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film size. Despite competition from formats such as 828, 126, 110, and APS, it remains so today.
135 camera film always comes perforated with Kodak Standard perforations.
The size of the 135 film frame has been adopted by many high-end digital single-lens reflex and digital mirrorless cameras, commonly referred to as "full frame". Even though the format is much smaller than historical medium format and large format film, it is much larger than image sensors in most compact cameras and smart phone cameras.17.5 mm film
17.5 mm film was a film gauge for as many of eight types of motion picture film stock, generally created by splitting unperforated 35 mm film.35 mm equivalent focal length
In photography, the 35 mm equivalent focal length is a measure that indicates the angle of view of a particular combination of a camera lens and film or sensor size. The term is useful because most photographers experienced with interchangeable lenses are most familiar with the 35 mm film format.
On any 35 mm film camera, a 28 mm lens is a wide-angle lens, and a 200 mm lens is a long-focus lens. However, now that digital cameras have mostly replaced 35 mm cameras, there is no uniform relation between the focal length of a lens and the angle of view, since the size of the camera sensor also determines angle of view, and sensor size is not standardized as film size was. The 35 mm equivalent focal length of a particular lens–sensor combination is the focal length that one would need for a 35 mm film camera to obtain the same angle of view.
Most commonly, the 35 mm equivalent focal length is based on equal diagonal angle of view. This definition also in the CIPA guideline DCG-001. Alternatively, it may sometimes be based on horizontal angle of view. Since 35 mm film is normally used for images with an aspect ratio (width-to-height ratio) of 3:2, while many digital cameras have a 4:3 aspect ratio, which have different diagonal-to-width ratios, these two definitions are often not equivalent.APS-C
Advanced Photo System type-C (APS-C) is an image sensor format approximately equivalent in size to the Advanced Photo System film negative in its C ("Classic") format, of 25.1×16.7 mm, an aspect ratio of 3:2.
Sensors approximating these dimensions are used in many digital single-lens reflex cameras (DSLRs), mirrorless interchangeable-lens cameras (MILCs), and a few large-sensor live-preview digital cameras. APS-C size sensors are also used in a few digital rangefinders.
Such sensors exist in many different variants depending on the manufacturer and camera model.
All APS-C variants are considerably smaller than 35 mm standard film which measures 36×24 mm. Because of this, devices with APS-C sensors are known as "cropped frame," especially when used in connection with lens mounts that are also used with sensors the size of 35 mm film: only part of the image produced by the lens is captured by the APS-C size sensor. Sensor sizes range from 20.7×13.8 mm to 28.7×19.1 mm, but are typically about 22.5×15 mm for Canon and 24×16 mm for other manufacturers. Each variant results in a slightly different angle of view from lenses at the same focal length and overall a much narrower angle of view compared to 35 mm film. This is why each manufacturer offers a range of lenses designed for its format.Anamorphic format
Anamorphic format is the cinematography technique of shooting a widescreen picture on standard 35 mm film or other visual recording media with a non-widescreen native aspect ratio. It also refers to the projection format in which a distorted image is "stretched" by an anamorphic projection lens to recreate the original aspect ratio on the viewing screen. (It should not be confused with anamorphic widescreen, a different video encoding concept that uses similar principles but different means.) The word anamorphic and its derivatives stem from the Greek words meaning "formed again". As a camera format, anamorphic format is losing popularity in comparison to "flat" (or "spherical") formats such as Super 35 mm film shot using spherical lenses; however, because most film movie projectors use anamorphic projection format, spherical format negatives are commonly converted into anamorphic prints for projection.
In the years since digital cinema cameras and projectors have become commonplace, anamorphic has experienced a considerable resurgence of popularity, due in large part to the higher base ISO sensitivity of digital sensors, which facilitates shooting at smaller apertures.Angiocardiography
Angiocardiography is contrast radiography of the heart and great vessels. A liquid radiocontrast agent, typically containing iodine, is injected into the bloodstream, then the tissues are examined using X-rays. To avoid dilution, the radiopaque material is typically introduced with a catheter, a process known as selective angiocardiography. Normally, rather than just a single image, hundreds of X-ray images are rapidly captured on high-speed serial media, such as 35 mm film or a digital imaging counterpart, thus allowing the motion to be observed. The process requires fasting before the test, with a sedative and an antihistamine being administered before the test.Aspect ratio (image)
The aspect ratio of an image describes the proportional relationship between its width and its height. It is commonly expressed as two numbers separated by a colon, as in 16:9. For an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this same length unit, the height will be measured to be y units.
For example, in a group of images that all have an aspect ratio of 16:9, one image might be 16 inches wide and 9 inches high, another 16 centimeters wide and 9 centimeters high, and a third might be 8 yards wide and 4.5 yards high. Thus, aspect ratio concerns the relationship of the width to the height, not an image's actual size.Canon Canonflex
The Canonflex is a Canon 35 mm film single-lens reflex (SLR) camera introduced in May 1959. Its standard lens is the Canon Camera Co. Super-Canomatic R 50mm lens f/1.8. The camera was in production for one year before it was replaced by the Canonflex R2000, adding a 1/2000 sec. shutter speed.Crop factor
In digital photography, the crop factor, format factor or focal length multiplier of an image sensor format is the ratio of the dimensions of a camera's imaging area compared to a reference format; most often, this term is applied to digital cameras, relative to 35 mm film format as a reference. In the case of digital cameras, the imaging device would be a digital sensor. The most commonly used definition of crop factor is the ratio of a 35 mm frame's diagonal (43.3 mm) to the diagonal of the image sensor in question; that is, CF=diag35mm / diagsensor. Given the same 3:2 aspect ratio as 35mm's 36 mm × 24 mm area, this is equivalent to the ratio of heights or ratio of widths; the ratio of sensor areas is the square of the crop factor.
The crop factor is used to compare the field of view and image quality of different cameras with the same lens. Multiplying a lens focal length by the crop factor gives the focal length of a lens that would yield the same field of view if used on the reference format. For example, a lens with a 50 mm focal length on an imaging area with a crop factor of 1.6 with respect to the reference format (usually 35 mm) will yield the same field of view that a lens with an 80 mm focal length will yield on the reference format. If it is desired to capture an image with the same field of view and image quality but different cameras, the aperture and ISO settings also need to be adjusted with respect to the crop factor. The focal length of the lens does not change by using a smaller imaging area; the field of view is correspondingly smaller because a smaller area of the image circle cast by the lens is used by the smaller imaging area.Ducati Sogno
The Ducati Sogno ("dream") was a half-frame 35 mm rangefinder camera made by Ducati in the 1950s at its Milan factory. The Sogno has been called a "miniature Leica" referring to its size and build quality; it is considerably smaller than a Leica III.The Sogno is unusual for having its controls, including the shutter release, operated by the left hand. It produces an 18 mm x 24 mm image on standard 35 mm film loaded in a special cassette provided with the camera.FIFA World Cup official films
Since 1954, FIFA has sanctioned an official documentary film for each World Cup. Up to 2002, 35 mm film was used for the footage.Full frame
In cinematography, full frame refers to the use of the full film gate at maximum width and height for 35 mm film cameras. It is sometimes also referred to as silent aperture, full gate, or a number of other similar word combinations. It is the original gate size pioneered by William Dickson and Thomas Edison in 1892 and first used in the short film Blacksmithing Scene. Full frame is generally used by all 4-perf films, whether silent, standard 35 (Academy ratio width), or Super 35. The introduction of Academy ratio in 1932 required that the lens mount needed to be shifted slightly horizontally to re-center the lens at the new center of frame; however, the gate size did not change as the extra negative information would be cropped out by lab processes in post-production. 4-perf Super 35 is nearly identical to the original full frame standard, although the lens mount requires vertical re-centering when common topline extraction is used. Hard mattes for all common ratios exist and either replace the film gate itself or are inserted within it. However, these are usually not used in the event that any reframing needs to be done.Image sensor format
Note: If you came here to get a quick understanding of numbers like 1/2.3, skip ahead to table of sensor formats and sizes. For a simplified discussion of image sensors see image sensor.
In digital photography, the image sensor format is the shape and size of the image sensor.
The image sensor format of a digital camera determines the angle of view of a particular lens when used with a particular sensor. Because the image sensors in many digital cameras are smaller than the 24 mm × 36 mm image area of full-frame 35-mm cameras, a lens of a given focal length gives a narrower field of view in such cameras.
Sensor size is often expressed as optical format in inches. Other measures are also used; see table of sensor formats and sizes below.
Lenses produced for 35-mm film cameras may mount well on the digital bodies, but the larger image circle of the 35-mm system lens allows unwanted light into the camera body, and the smaller size of the image sensor compared to 35-mm film format results in cropping of the image. This latter effect is known as field of view crop. The format size ratio (relative to the 35-mm film format) is known as the field of view crop factor, crop factor, lens factor, focal length conversion factor, focal length multiplier or lens multiplier.Kodak DCS 400 series
The Kodak DCS 400 series was a series of Nikon based digital SLR cameras with sensor and added electronics produced by Eastman Kodak.
The cameras in this series include the 1.5-megapixel DCS 420 (introduced in August 1994), the 1.5-mpx DCS 410 (introduced in 1996), and the 6.2-mpx DCS 460 (introduced in March 1995). In addition, Kodak sold a version of the back from the DCS 460 adapted for medium format bodies as the DCS 465. Kodak also made a camera especially for Associated Press. It was called NC2000 (based on the Nikon N90/F90), later upgraded to NC2000e (based on the Nikon N90s/F90x) using many of the same components as were used for the DCS 400 series. Kodak also used the imaging component and electronics of the DCS 420 to produce a digital version of the Nikonos underwater camera, which was produced in limited numbers for military and scientific applications as the Kodak DCS 425.
In addition to the standard colour version, Kodak made monochrome and infrared versions of the DCS 420, which were made to order as the 420m and 420IR respectively. There were also monochrome versions of the DCS 460 and DCS 465, with the same nomenclature. The non-colour versions are very rare and tend to collect high prices at auctions and second-hand brokers.
The DCS 400-series were based on the Nikon N90s 35 mm film camera (called F90x in Europe). The DCS 410 and some early versions of the DCS 420 and 460 were based on the Nikon N90/F90 body. After the Nikon N90s/F90x was introduced in late 1994, Kodak started using that model as basis for the DCS 400-series. The camera body could be converted back to a film camera by removing the digital component, and replacing the digital back with a standard back.
All cameras in the series used a 12 bit/channel CCD. The 1.5 Mpx sensor used in the DCS 410 and DCS 420 measures 9.2x13.8 mm (2.6x crop factor compared to the 35 mm film format). The 6.2 Mpx sensor used in the DCS 460 and DCS 465 measures 18.4x27.6mm (1.3x crop). The 1.3 Mpx sensor used in the NC2000 and NC2000e measures 16.4x20.5mm (1.6x crop) with an unusual aspect ratio (5:4).
In 1995, the DCS 460 was the highest resolution digital camera available and its list price was US$35,600. When it closed out in November 2000, the price had dropped to US$2,500.Medium format (film)
Medium format has traditionally referred to a film format in still photography and the related cameras and equipment that use film. Nowadays, the term applies to film and digital cameras that record images on media larger than 24 mm × 36 mm (0.94 in × 1.42 in) (full-frame) (used in 35 mm (1.4 in) photography), but smaller than 4 in × 5 in (100 mm × 130 mm) (which is considered to be large-format photography).
In digital photography, medium format refers either to cameras adapted from medium-format film photography uses or to cameras making use of sensors larger than that of a 35 mm film frame. Often, medium-format film cameras can be retrofitted with digital camera backs, converting them to digital cameras, but some of these digital backs, especially early models, use sensors smaller than a 35 mm film frame. As of 2013, medium-format digital photography sensors were available in sizes of up to 40.3 by 53.7 mm, with 60 million pixels for use with commonly available professional medium-format cameras. Sensors used in special applications such as spy satellites can be even larger but are not necessarily described as medium-format equipment.In the film world, medium format has moved from being the most widely used film size (the 1900s through 1950s) to a niche used by professionals and some amateur enthusiasts, but one which is still substantially more popular than large format. In digital photography, medium format has been a very expensive option, with lower-cost options such as the Fujifilm GFX 50R still retailing for $4,500.While at one time a variety of medium-format film sizes were produced, today the vast majority of the medium-format film is produced in the 6 cm 120 and 220 sizes. Other sizes are mainly produced for use in antique cameras, and many people assume 120/220 film is being referred to when the term medium format is used.
The general rule with consumer cameras—as opposed to specialized industrial, scientific, and military equipment—is the more cameras sold, the more sophisticated the automation features available. Medium-format cameras made since the 1950s are generally less automated than smaller cameras made at the same time, having high image quality as their primary advantage. For example, autofocus became available in consumer 35 mm cameras in 1977, but did not reach medium format until the late 1990s, and has never been available in a consumer large format camera.Nemesis (Stargate SG-1)
"Nemesis" is the last episode from season 3 of the science fiction television series Stargate SG-1. Written by Robert C. Cooper and directed by Martin Wood, the episode first aired in the United Kingdom on Sky One on February 11, 2000, and had its American premiere on Showtime on March 8, 2000. The episode sets up the Replicators as a new major enemy, ending in a cliffhanger that is resumed in the season 4 premiere "Small Victories".
"Nemesis" was the first SG-1 episode to be filmed entirely on 35 mm film before the series switched from 16 mm film to 35 mm film for all purposes in season 4. A visual effects milestone for the series, the episode was nominated for an Emmy Award in the "Outstanding Special Visual Effects for a Series" category, and won a Leo Award for "Best Overall Sound in a Dramatic Series".Sony Dynamic Digital Sound
Sony Dynamic Digital Sound (Japanese: ソニーダイナミックデジタルサウンド, Hepburn: Sonī Dainamikku Dejitaru Saundo, SDDS) is a cinema sound system developed by Sony, from which compressed digital sound information is recorded on both outer edges of the 35 mm film release print. The system supports up to eight independent channels of sound: five front channels, two surround channels and a single sub-bass channel. The eight channel arrangement is similar to large format film magnetic sound formats like Cinerama and Cinemiracle. The five front channels are useful for very large cinema auditoriums where the angular distance between center and left/right channels may be considerable. SDDS decoders provide the ability to downmix to fewer channels if required.Super 35
Super 35 (originally known as Superscope 235) is a motion picture film format that uses exactly the same film stock as standard 35 mm film, but puts a larger image frame on that stock by using the negative space normally reserved for the optical analog sound track.Techniscope
Techniscope or 2-perf is a 35 mm motion picture camera film format introduced by Technicolor Italia in 1960. The Techniscope format uses a two film-perforation negative pulldown per frame, instead of the standard four-perforation frame usually exposed in 35 mm film photography. Techniscope's 2.33:1 aspect ratio is easily cropped to the 2.39:1 widescreen ratio, because it uses half the amount of 35 mm film stock and standard spherical lenses. Thus, Techniscope release prints are made by anamorphosizing and enlarging each frame by a factor of two.