35mm Format
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135 film, more popularly referred to as 35 mm film or 35 mm, is a
format Format may refer to: Printing and visual media * Text formatting, the typesetting of text elements * Paper formats, or paper size standards * Newspaper format, the size of the paper page Computing * File format, particular way that informatio ...
of
photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of th ...
used for still
photography Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed ...
. It is a film with a
film gauge Film gauge is a physical property of photographic or motion picture film stock which defines its width. Traditionally, the major movie film gauges are 8 mm, 16 mm, 35 mm, and 65/70 mm (in this case 65 mm for the negative and 70 mm f ...
of loaded into a standardized type of magazine – also referred to as a cassette or cartridge – for use in 135 film
camera A camera is an Optics, optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), ...
s. The engineering standard for this film is controlled by
ISO ISO is the most common abbreviation for the International Organization for Standardization. ISO or Iso may also refer to: Business and finance * Iso (supermarket), a chain of Danish supermarkets incorporated into the SuperBest chain in 2007 * Iso ...
1007 titled '135-size film and magazine'. The term 135 was introduced by
Kodak The Eastman Kodak Company (referred to simply as Kodak ) is an American public company that produces various products related to its historic basis in analogue photography. The company is headquartered in Rochester, New York, and is incorpor ...
in 1934 as a designation for 35 mm film specifically for still photography, perforated with Kodak Standard perforations. It quickly grew in popularity, surpassing
120 film 120 is a film format for still photography introduced by Kodak for their '' Brownie No. 2'' in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film. 120 film survives to this day as the only ...
by the late 1960s to become the most popular photographic film size. Despite competition from formats such as
828 __NOTOC__ Year 828 ( DCCCXXVIII) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire * Siege of Syracuse: The Muslims under Asad ibn al-Furat defeat ...
, 126,
110 110 may refer to: *110 (number), natural number *AD 110, a year *110 BC, a year *110 film, a cartridge-based film format used in still photography *110 (MBTA bus), Massachusetts Bay Transportation Authority bus route *110 (song), 2019 song by Capi ...
, and APS, it remains the most popular film size today. The size of the 135 film frame with its aspect ratio of 1:1.50 has been adopted by many high-end
digital single-lens reflex A digital single-lens reflex camera (digital SLR or DSLR) is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor. The reflex design scheme is the primary difference between ...
and digital mirrorless cameras, commonly referred to as " full frame". Even though the format is much smaller than historical
medium format Medium format has traditionally referred to a film format in 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 the used in 35&nbs ...
and
large format Large format refers to any imaging format of or larger. Large format is larger than "medium format", the or size of Hasselblad, Mamiya, Rollei, Kowa, and Pentax cameras (using 120- and 220-roll film), and much larger than the frame ...
film, being historically referred to as miniature format or small format, it is much larger than
image sensor An image sensor or imager is a sensor that detects and conveys information used to make an image. It does so by converting the variable attenuation of light waves (as they pass through or reflect off objects) into signals, small bursts of c ...
s in most compact cameras and smart phone cameras.


Characteristics


Cassette

Individual rolls of 135 film are enclosed in single-spool, light-tight, metal cassettes to allow cameras to be loaded in daylight. The film is clipped or taped to a spool and exits via a slot lined with flocking. The end of the film is cut on one side to form a leader. It has the same dimensions and perforation pitch as 35 mm movie print film (also called "long pitch", KS-1870, whereas 35 mm professional motion picture camera films are always "short pitch", BH-1866). Most cameras require the film to be rewound before the camera is opened. Some motorized cameras unwind the film fully upon loading and then expose the images in reverse order, returning the film to the cassette; this protects all images except the last one or two, should the camera back be accidentally opened.
Disposable camera A disposable or single-use camera is a simple box camera meant to be used once. Most use fixed-focus lenses. Some are equipped with an integrated flash unit, and there are even waterproof versions for underwater photography. Internally, the camera ...
s use the same technique so that the user does not have to rewind. Since the 1980s, film cassettes have been marked with a
DX encoding DX (Digital indeX) encoding is an ANSI and I3A standard, originally introduced by Kodak in March 1983, for marking 135 and APS photographic film and film cartridges. It consists of several parts, a latent image DX film edge barcode on the film ...
six-digit
barcode A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly referred to as linear or o ...
pattern, which identifies the manufacturer and film type (and thus processing method), and the number of exposures, for the use of photofinishing laboratories. The cassettes are also manufactured with a Camera Auto Sensing code constructed as two rows of six rectangular areas on the metal cassette surface which are either conductive or insulating, representing 32 possible film speeds, eight possible film lengths, and four possible values of exposure tolerance or latitude. Conforming cameras detect at least some of these areas; only three contacts are needed to set a light meter for the four most popular film speeds.


Film type and speed

The 135 film has been made in several emulsion types and sensitivities (film speeds) described by
ISO ISO is the most common abbreviation for the International Organization for Standardization. ISO or Iso may also refer to: Business and finance * Iso (supermarket), a chain of Danish supermarkets incorporated into the SuperBest chain in 2007 * Iso ...
standards. Since the introduction of digital cameras the most usual films have colour emulsions of ISO 100/21° to ISO 800/30°. Films of lower sensitivity (and better picture quality) and higher sensitivity (for low light) are for more specialist purposes. There are colour and monochrome films, negative and positive. Monochrome film is usually panchromatic; orthochromatic has fallen out of use. Film designed to be sensitive to infrared radiation can be obtained, both monochrome and with false-colour (or pseudocolour) rendition. More exotic emulsions have been available in 135 than other roll-film sizes.


Image format

The term 135 format usually refers to a 24×36 mm
film format A film format is a technical definition of a set of standard characteristics regarding image capture on photographic film for still images or film stock for filmmaking. It can also apply to projected film, either slides or movies. The primary ...
, commonly known as 35 mm format. The 24×36 mm format is common to digital
image sensor An image sensor or imager is a sensor that detects and conveys information used to make an image. It does so by converting the variable attenuation of light waves (as they pass through or reflect off objects) into signals, small bursts of c ...
s, where it is typically referred to as full frame format. On 135 film, the longer dimension of the 24×36 mm frame runs parallel to the length of the film. The perforation size and pitch are according to the standard specification KS-1870. For each frame, the film advances 8 perforations. This is specified as 38.00 mm. This allows for 2 mm gaps between frames. Camera models typically have different locations for the sprocket which advances the film. Therefore, each camera model's frame may vary in position relative to the perforations. The film is approximately 0.14 mm thick. Other image formats have been applied to 135 film, such as the
half-frame A half-frame camera is a camera using a film format at half the usual exposure format. A common variety is the 18×24 mm format on regular 135 film. It is the normal exposure format on 35mm movie cameras. For still cameras using the 35mm fi ...
format of 18×24 mm which earned some popularity in the 1960s, and the 24×24 mm of the Robot cameras. The successful range of
Olympus Pen F The Olympus Pen F, Pen FT and Pen FV are very similar half-frame 35 mm single-lens reflex (SLR) cameras with interchangeable lenses produced by Olympus of Japan between 1963-1966 (Pen F), 1966-1972 (Pen FT) and 1967-1970 (Pen FV). The ori ...
cameras utilized the smaller half-frame size, allowing the design of a very compact SLR camera. Unusual formats include the 24×32 mm and 24×34 mm on the early Nikon
rangefinders A rangefinder (also rangefinding telemeter, depending on the context) is a device used to measure distances to remote objects. Originally optical devices used in surveying, they soon found applications in other fields, such as photography an ...
, and 24×23 mm for use with some
stereo camera A stereo camera is a type of camera with two or more lenses with a separate image sensor or film frame for each lens. This allows the camera to simulate human binocular vision, and therefore gives it the ability to capture three-dimensional ...
s. In 1967, the Soviet KMZ factory introduced a 24×58 mm panoramic format with its Horizont camera (descendants of which are called, in the Roman alphabet,
Horizon The horizon is the apparent line that separates the surface of a celestial body from its sky when viewed from the perspective of an observer on or near the surface of the relevant body. This line divides all viewing directions based on whether i ...
). In 1998,
Hasselblad Victor Hasselblad AB is a Swedish manufacturer of medium format cameras, photographic equipment and image scanners based in Gothenburg, Sweden. The company originally became known for its classic analog medium-format cameras that used a waist ...
and
Fuji Fuji may refer to: Places China * Fuji, Xiangcheng City (付集镇), town in Xiangcheng City, Henan Japan * Mount Fuji, the tallest mountain in Japan * Fuji River * Fuji, Saga, town in Saga Prefecture * Fuji, Shizuoka, city in Shizuoka Prefec ...
introduced a 24×65 mm panoramic format with their XPan/TX-1 camera. There is also a 21×14 mm format used by Tessina subminiature camera.


Length

The film is available in lengths for varying numbers of exposures. The standard full-length roll has always been 36 exposures (assuming a standard 24×36 frame size). Through about 1980, 20 exposure rolls were the only shorter length with widespread availability. Since then, 20 exposure rolls have been largely discontinued in favour of 24 and 12 exposure rolls. The length of film provided includes the length required for the indicated number of exposures plus sufficient additional length for the film spoiled by being exposed to ambient light when it is drawn out of the canister, across the back of the camera, and securely engaged with the film advancing spool, before the camera back is closed. A camera that uses less than the maximum distance between the spools may be able to make one additional exposure. Self-loading cameras that load the film after being closed don’t spoil the additional length provided for conventional loading and can make that additional length available for two or three additional exposures. The same length can be available for exposures in any camera if it is loaded without exposing the film to light, e.g. in a darkroom or a dark bag. A 27-exposure disposable camera uses a standard 24-exposure cassette loaded in the dark. Other, mostly shorter lengths have been manufactured. There have been some 6, 8, 10, and 15 exposure rolls given away as samples, sometimes in disposable cameras, or used by insurance adjusters to document damage claims. Twelve-exposure rolls have been used widely in the daily press. Photographers who load their own cassettes can use any length of film – with thinner film base up to 45 exposures will fit. Ilford at one time made HP5 black-and-white film on a thin polyester base, which allowed 72 exposures in a single cassette. They produced special reels and tanks to allow this to be processed.


History


35 mm still cameras

The 135 film size is derived from earlier still cameras using lengths of 35 mm cine film, the same size as, but with different perforations than, 135 film. The 35 mm film standard for motion picture film was established in
Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventio ...
's lab by
William Kennedy Laurie Dickson William Kennedy Laurie Dickson (3 August 1860 – 28 September 1935) was a British inventor who devised an early motion picture camera under the employment of Thomas Edison. Early life William Kennedy Dickson was born on 3 August 1860 in ...
. Dickson took 70 mm film stock supplied by
George Eastman George Eastman (July 12, 1854March 14, 1932) was an American entrepreneur who founded the Eastman Kodak Company and helped to bring the photographic use of roll film into the mainstream. He was a major philanthropist, establishing the Eastman ...
's Eastman Kodak Company. The 70 mm film was cut lengthwise into two equal width (35 mm) strips, spliced together end to end, and then perforated along both edges. The original picture size was 18×24 mm (half the full frame size later used in still photography). There were four perforations on each side of a motion picture frame. While the
Leica camera Leica Camera AG () is a German company that manufactures cameras, optical lenses, photographic lenses, binoculars, Telescopic sight, rifle scopes and microscopes. The company was founded by Ernst Leitz in 1869 (Ernst Leitz Wetzlar), in Wetz ...
popularized the format, several 35 mm still cameras used perforated movie film before the Leica was introduced in the 1920s. The first patent for one was issued to Leo, Audobard and Baradat in England in 1908. The first full-scale production camera was the Homeos, a stereo camera, produced by Jules Richard in 1913, and was sold until 1920. It took 18x24 mm stereo pairs, using two Tessar lenses. In 1909, the French designed a device for small-format photography, the "", which used the 35 mm perforated film to take consecutive hundred views in 18×24 mm. He manufactured, won the gold medal in the
Concours Lépine Concours may refer to: * Concours d'Elegance, a competition among car owners on the appearance of their cars * EU Concours, a selection process for staff of the EU institutions * A competitive examination * Cadillac Concours, an automobile model * ...
, and in 1910 sold at a small scale and without much success. The first big-selling 35 mm still camera was the American Tourist Multiple, which also appeared in 1913, at a cost of $175 (at today's prices, the same cost as a modern $3000 Leica.) The first camera to take full-frame 24×36 mm exposures seems to be the Simplex, introduced in the U.S. in 1914. It took either 800 half-frame or 400 full-frame shots on 50 ft (15.2 m) rolls. The Minigraph, by Levy-Roth of Berlin, another half-frame small camera was sold in Germany in 1915. The patent for the Debrie Sept camera, a combination 35 mm still and movie camera was issued in 1918; the camera sold from 1922. The Furet camera made and sold in France in 1923 took full-frame 24x36 mm negatives, and was the first cheap small 35 mm camera of similar appearance to more modern models.


Leica

The
Leica camera Leica Camera AG () is a German company that manufactures cameras, optical lenses, photographic lenses, binoculars, Telescopic sight, rifle scopes and microscopes. The company was founded by Ernst Leitz in 1869 (Ernst Leitz Wetzlar), in Wetz ...
designed by
Oskar Barnack Oskar Barnack (Nuthe-Urstromtal, Brandenburg, 1 November 1879 – Bad Nauheim, Hesse, 16 January 1936) was a German inventor and photographer who built, in 1913, what would later become the first commercially successful 35mm still-camera, sub ...
used 35 mm film, and proved that a format as small as 24 mm × 36 mm was suitable for professional photography. Although Barnack designed his prototype camera around 1913, the first experimental production run of ur-Leicas (Serial No. 100 to 130) did not take place until 1923. Full-scale production of the Leica did not begin until 1925. While by that time there were at least a dozen other 35 mm cameras available, the Leica was a success, and came to be associated with the format. Mostly because of this 35 mm popularity, as well as the entire company legacy, early Leica cameras are considered as highly collectible items. The original Leica prototype holds the record as being the world's most expensive camera, selling for €2.16 million in 2012.


Pre-loaded cassettes and Kodak Retina cameras

In the earliest days, the photographer had to load the film into reusable cassettes and, at least for some cameras, cut the film leader. In 1934, Kodak introduced a ''135'' daylight-loading single-use cassette. This cassette was engineered so that it could be used in both Leica and
Zeiss Ikon Carl Zeiss AG (), branded as ZEISS, is a German manufacturer of optical systems and optoelectronics, founded in Jena, Germany in 1846 by optician Carl Zeiss. Together with Ernst Abbe (joined 1866) and Otto Schott (joined 1884) he laid the ...
Contax cameras along with the camera for which it was invented, namely the
Kodak Retina Retina was the brand-name of a long-running series of German-built Kodak 35mm cameras, produced from 1934 until 1969. Kodak Retina cameras were manufactured in Stuttgart-Wangen by the Kodak AG Dr. Nagel Werk which Kodak had acquired in Dece ...
camera. The Retina camera and this daylight loading cassette were the invention of Dr. August Nagel of the ''Kodak AG Dr. Nagel Werk'' in Stuttgart. Kodak bought Dr. August Nagel's company in December, 1931, and began marketing the ''Kodak Retina'' in the summer of 1934. The first Kodak Retina camera was a Typ 117. The 35 mm Kodak Retina camera line remained in production until 1969. Kodak also introduced a line of American made cameras that were simpler and more economical than the Retina. Argus, too, made a long-lived range of 35 mm cameras; notably the
Argus C3 The Argus C3 was a low-priced rangefinder camera mass-produced from 1939 to 1966 by Argus in Ann Arbor, Michigan, United States. The camersold over 2.2 million units making it one of the most popular American cameras in history. Due to its shape ...
. Kodak launched 135-format
Kodachrome Kodachrome is the brand name for a color reversal film introduced by Eastman Kodak in 1935. It was one of the first successful color materials and was used for both cinematography and still photography. For many years Kodachrome was widely used ...
color film in 1936. AGFA followed with the introduction of ''Agfacolor Neu'' later in the same year. The designations 235 and 435 refer to 35 mm film in daylight-loading spools, that could be loaded into Contax or Leica style reusable cassettes, respectively, without need of a darkroom. The 335 was a daylight loading spool for the 24 × 23 mm stereo format.


The reflex camera

Reflex viewfinders, both twin-and single-lens, had been used with earlier cameras using plates and rollfilm. The first 35 mm single-lens reflex (SLR) was the
Kine Exakta The Kine Exakta was the first 35mm single-lens reflex (SLR) still camera in regular production. It was presented by Ihagee Kamerawerk Steenbergen GmbH, Dresden at the Leipziger Frühjahrsmesse in March 1936. The Exakta name had already been use ...
, introduced in 1936.
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
interrupted development of the type. After the war, Exakta resumed development and the Contax S model with the now familiar
pentaprism A pentaprism is a five-sided reflecting prism used to deviate a beam of light by a constant 90°, even if the entry beam is not at 90° to the prism. The beam reflects inside the prism ''twice'', allowing the transmission of an image through a r ...
viewing feature was introduced in 1949. In the 1950s, the SLR also began to be produced in Japan by such companies as
Asahi Asahi (朝日, 旭, or あさひ) means "morning sun" in Japanese and may refer to: Cities * Asahi, Chiba (旭市; ''Asahi-shi'') Wards * Asahi-ku, Osaka (旭区; ''Asahi-ku'') * Asahi-ku, Yokohama (旭; ''Asahi-ku'') Towns * Asahi, Aichi (旭 ...
and Miranda. Asahi's Pentax introduced the instant-return mirror, important for the popularity of SLRs; until then, the viewfinder on an SLR camera blanked as the mirror sprang out of the optical path just before taking the picture, returning when the film was wound on.
Nikon (, ; ), also known just as Nikon, is a Japanese multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging products. The companies held by Nikon form the Nikon Group. Nikon's products include cameras, camera ...
's F model, introduced in March 1959, was a
system camera A system camera or camera body is a camera with interchangeable components that constitutes the core of a system. Early representatives include Leica I Schraubgewinde (1930), Exakta (1936) and the Nikon F (1959). System cameras are often sin ...
that greatly improved the quality and utility of 35 mm format cameras, encouraging professionals (especially photojournalists) to switch from larger format cameras to the versatile, rugged, and fast SLR design. Numerous other film formats waxed and waned in popularity, but by the 1970s, interchangeable-lens SLR cameras and smaller rangefinders, from expensive Leicas to "point-and-shoot" pocket cameras, were all using 35 mm film, and manufacturers had proliferated. Colour films improved, both for print negatives and reversal slides, while black-and-white films offered smoother grain and faster speeds than previously available. Since 35 mm was preferred by both amateur and professional photographers, makers of film stock have long offered the widest range of different film speeds and types in the format. The DX film-speed encoding system was introduced in the 1980s, as were single-use cameras pre-loaded with 35 mm film and using plastic lenses of reasonable enough quality to produce acceptable snapshots. Automated all-in-one processing and printing machines made 35 mm developing easier and less expensive, so that quality colour prints became available not only from photographic specialty stores, but also from supermarkets, drugstores, and big box retailers, often in less than an hour.


From 1996

In 1996, a smaller format called
Advanced Photo System Advanced Photo System (APS) is a discontinued film format for still photography first produced in 1996. It was marketed by Eastman Kodak under the brand name Advantix, by FujiFilm under the name Nexia, by Agfa under the name Futura and by Ko ...
(APS) was introduced by a consortium of photographic companies in an attempt to supersede 135 film. Due in part to its small negative size, APS was not taken seriously as a professional format, despite the production of APS SLRs. In the point-and-shoot markets at which the format was primarily aimed, it enjoyed moderate initial success, but still never rivalled the market penetration of 135. Within five years of its launch, cheap digital compact cameras started becoming widely available, and APS sales plummeted. While they have shifted the vast majority of their product lines to digital, major camera manufacturers such as Canon and Nikon continue to make expensive professional-grade 35 mm film SLRs (such as the Canon EOS-1v and the
Nikon F6 The Nikon F6 is a 35 mm film single-lens reflex camera body manufactured by Nikon between 2004 and 2020. It is the sixth top-of-the-line professional film camera in Nikon's line. The Nikon F6 is designed by Nikon and was manufactured at their S ...
). Introductory 35 mm SLRs, compact film point-and-shoot cameras, and single-use cameras continue to be built and sold by a number of makers. Leica finally introduced the digital
Leica M8 The Leica M8 is the first digital camera in the rangefinder M series introduced by Leica Camera AG on 14 September 2006. It uses an APS-H 10.3-megapixel Kodak KAF-10500 CCD image sensor. As of 15 November 2014, the most recent firmware version ...
rangefinder in 2007, but continues to make its M series rangefinder film cameras and lenses. A
digital camera back A digital camera back is a device that attaches to the back of a camera in place of the traditional negative film holder and contains an electronic image sensor. This lets cameras that were designed to use film take digital photographs. Thes ...
for the
Leica R9 The Leica R8 & R9 are manual focus 35 mm single-lens reflex cameras produced by the German firm Leica as the final models of their R series. Development of the R8 began in 1990: the camera was introduced at the 1996 photokina trade show, ...
SLR camera was discontinued in 2007. On March 25, 2009, Leica discontinued the R9 SLR and R-series lenses.


Use in digital cameras

Digital sensors are available in various sizes. Professional DSLR cameras usually use
digital image sensor An image sensor or imager is a sensor that detects and conveys information used to make an image. It does so by converting the variable attenuation of light waves (as they refraction, pass through or reflection (physics), reflect off objects) in ...
s which approximate the dimensions of the 35 mm format, sometimes differing by fractions of a millimeter on one or both dimensions. Since 2007, Nikon has referred to their 35 mm format by the
trade mark A trademark (also written trade mark or trade-mark) is a type of intellectual property consisting of a recognizable sign, design, or expression that identifies products or services from a particular source and distinguishes them from oth ...
FX. Other makers of 35 mm format digital cameras, including Leica,
Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
, and
Canon Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base * Literary canon, an accepted body of works considered as high culture ** Western ca ...
, refer to their 35 mm sensors simply as full frame. Most consumer DSLR cameras use smaller sensors, with the most popular size being APS-C which measures around 23mm x 15mm (giving it a
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 ca ...
of 1.6). Compact cameras have smaller sensors with a crop factor of around 3 to 6.


Lenses

A true
normal lens In photography and cinematography, a normal lens is a lens that reproduces a field of view that appears "natural" to a human observer. In contrast, depth compression and expansion with shorter or longer focal lengths introduces noticeable, and som ...
for 35 mm format would have a focal length of 43 mm, the diagonal measurement of the format. However, lenses of 43 mm to 60 mm are commonly considered ''normal'' lenses for the format, in mass production and popular use. Common focal lengths of lenses made for the format include 24, 28, 35, 50, 85, 105, and 135 mm. Most commonly, a 50 mm lens is the one considered ''normal''; any lens shorter than this is considered a ''wide angle'' lens and anything above is considered a ''telephoto'' lens. Even then, wide angles shorter than 24 mm is called an ''extreme wide angle''. Lenses above 50 mm but up to about 100 mm are called short telephoto or sometimes, as ''portrait telephotos'', from 100 mm to about 200 mm are called ''medium'' telephotos, and above 300 mm are called ''long'' telephotos. With many smaller formats now common (such as APS-C), lenses are often advertised or marked with their "35 mm equivalent" or "full-frame equivalent" focal length as a mnemonic, due to the historic prevalence of the 35 mm format. This 'equivalent' is computed by multiplying (a) the true focal length of the lens by (b) the ratio of the diagonal measurement of the native format to that of the 35 mm format. As a result, a lens for an APS-C (18×24 mm) format camera body with a focal length of 40 mm, might be described as "60 mm (35 mm equivalent)." Although its true focal length remains 40 mm, its angle of view is equivalent to that of a 60 mm lens on a 35 mm format (24×36 mm) camera. Another example is the lens of the 2/3 inch format Fujifilm X10, which is marked with its true zoom range "7.1–28.4 mm" but has a 35 mm-equivalent zoom range of "28-112 mm".


See also

*
List of color film systems This is a list of color film processes known to have been created for photographing and exhibiting motion pictures in color since the first attempts were made in the late 1890s. It is limited to "natural color" processes, meaning processes in which ...


References


External links

* {{DEFAULTSORT:135 Film Film formats Film 135 Kodak photographic films fr:Format 35 mm#Utilisation en photographie