Photographic film
Encyclopedia
- This article is mainly concerned with still photographyPhotographyPhotography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
film. For motion picture film, please see film stockFilm stockFilm stock is photographic film on which filmmaking of motion pictures are shot and reproduced. The equivalent in television production is video tape.-1889–1899:...
.
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
(polyester
Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
, PET
Polyethylene terephthalate
Polyethylene terephthalate , commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination...
, nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
or cellulose acetate
Cellulose acetate
Cellulose acetate , first prepared in 1865, is the acetate ester of cellulose. Cellulose acetate is used as a film base in photography, as a component in some adhesives, and as a frame material for eyeglasses; it is also used as a synthetic fiber and in the manufacture of cigarette filters and...
) coated with an emulsion
Photographic emulsion
Photographic emulsion is a light-sensitive colloid, such as gelatin, coated onto a substrate. In silver-gelatin photography, the emulsion consists of silver halide crystals suspended in gelatin, and the substrate may be glass, plastic film, paper or fabric....
containing light-sensitive silver halide
Silver halide
A silver halide is one of the compounds formed between silver and one of the halogens — silver bromide , chloride , iodide , and three forms of silver fluorides. As a group, they are often referred to as the silver halides, and are often given the pseudo-chemical notation AgX...
salts (bonded by gelatin
Gelatin
Gelatin is a translucent, colorless, brittle , flavorless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing. Substances containing gelatin or functioning in a similar...
) with variable crystal sizes that determine the sensitivity, contrast and resolution
Image resolution
Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....
of the film. When the emulsion is sufficiently exposed to light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
(or other forms of electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
such as X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s), it forms a latent
Latent image
A latent image on photographic film is an invisible image produced by the exposure of the film to light. When the film is developed, the area that was exposed darkens and forms a visible image...
(invisible) image. Chemical processes can then be applied to the film to create a visible image, in a process called film developing.
In black-and-white photographic film there is usually one layer of silver salts. When the exposed grains are developed, the silver salts are converted to metallic silver, which blocks light and appears as the black part of the film negative.
Color film uses at least three layers. Dyes, which adsorb
Adsorption
Adsorption is the adhesion of atoms, ions, biomolecules or molecules of gas, liquid, or dissolved solids to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. It differs from absorption, in which a fluid permeates or is dissolved by a liquid or solid...
to the surface of the silver salts, make the crystals sensitive to different colors. Typically the blue-sensitive layer is on top, followed by the green and red layers. During development, the exposed silver salts are converted to metallic silver, just as with black-and-white film. But in a color film, the by-products of the development reaction simultaneously combine with chemicals known as color couplers that are included either in the film itself or in the developer solution to form colored dyes. Because the by-products are created in direct proportion to the amount of exposure and development, the dye clouds formed are also in proportion to the exposure and development. Following development, the silver is converted back to silver salts in the bleach step. It is removed from the film in the fix step. This leaves behind only the formed color dyes, which combine to make up the colored visible image.
Newer color films, like Kodacolor II
Kodacolor (still photography)
In still photography, Kodak's Kodacolor brand has been associated with various color negative films since 1942. Kodak claims that Kodacolor print film was the world's first true color negative film...
, have as many as 12 emulsion layers, with upwards of 20 different chemicals in each layer.
Due to film photography's long history of widespread use, there are now around one trillion pictures on photographic film or photographic paper
Photographic paper
Photographic paper is paper coated with light-sensitive chemicals, used for making photographic prints.Photographic paper is exposed to light in a controlled manner, either by placing a negative in contact with the paper directly to produce a contact print, by using an enlarger in order to create a...
in the world, enough to cover an area of around ten thousand square kilometres (4000 square miles), about half the size of Wales.
Film basics
There are several types of photographic film, including:- Print film, when developed, turns into a negativeNegative (photography)In photography, a negative may refer to three different things, although they are all related.-A negative:Film for 35 mm cameras comes in long narrow strips of chemical-coated plastic or cellulose acetate. As each image is captured by the camera onto the film strip, the film strip advances so that...
with the colors (or black and white values, in black-and-white film) inverted. This type of film must be "printed"—that is either enlarged by projecting through a lens, or placed in direct contact as light shines through it—onto photographic paperPhotographic paperPhotographic paper is paper coated with light-sensitive chemicals, used for making photographic prints.Photographic paper is exposed to light in a controlled manner, either by placing a negative in contact with the paper directly to produce a contact print, by using an enlarger in order to create a...
(which in turn is itself developed) in order to be viewed as intended. Print films are available in both black-and-whiteBlack-and-whiteBlack-and-white, often abbreviated B/W or B&W, is a term referring to a number of monochrome forms in visual arts.Black-and-white as a description is also something of a misnomer, for in addition to black and white, most of these media included varying shades of gray...
and colorColor print filmColor print film is the most common type of photographic film in consumer use. Print film produces a negative image when it is developed, requiring it to be reversed again when it is printed on to photographic paper....
. Color print films use an orange color correction mask to correct for unwanted dye absorptions and improve color accuracy. Although color processing is more complex and temperature-sensitive than black-and-white processing, the great popularity of color and minimal use of black-and-white prompted the design of black-and-white film which is processed in exactly the same way as a standard color film. - Color reversal film after development is called a transparencyTransparency (photography)In photography, a reversal film is a type of photographic film that produces a positive image on a transparent base. Also known as dias or slide. The film is processed to produce transparencies or diapositives instead of negatives and prints...
and can be viewed directly using a loupeLoupeA loupe is a simple, small magnification device used to see small details more closely. Unlike a magnifying glass, a loupe does not have an attached handle, and its focusing lens are contained in an opaque cylinder or cone. Loupes are also called hand lenses .- Optics :Three basic types of loupes...
or projectorSlide projectorA slide projector is an opto-mechanical device to view photographic slides. Slide projectors were common in the 1950s to the 1970s as a form of entertainment; family members and friends would gather to view slide shows...
. Reversal film mounted with plastic or cardboard for projection is often called a slide. It is also often marketed as "slide" film. This type of film is often used to produce digital scansFilm scannerA film scanner is a device made for scanning photographic film directly into a computer without the use of any intermediate printmaking. It provides several benefits over using a flatbed scanner to scan in a print of any size: the photographer has direct control over cropping and aspect ratio from...
or color separations for mass-market printingPrintingPrinting is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
. Photographic prints can be produced from reversal film, but the process is expensive and not as simple as that for print film. - Black-and-white reversal film exists, but is uncommon. Conventional black-and-white negative stock can be reversal-processed, to give black & white slides, as by dr5 Chrome. Some kits were available to enable B&W reversal processing to be done by home-processors, but most are discontinued. B&W transparencies can be produced from almost all B&W films.
In order to produce a usable image, the film needs to be exposed
Exposure (photography)
In photography, exposure is the total amount of light allowed to fall on the photographic medium during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value and scene luminance over a specified area.In photographic jargon, an exposure...
properly. The amount of exposure variation that a given film can tolerate while still producing an acceptable level of quality is called its exposure latitude. Color print film generally has greater exposure latitude than other types of film. Additionally, because print film must be printed to be viewed, after-the-fact corrections for imperfect exposure are possible during the printing process.
The concentration of dyes or silver salts remaining on the film after development is referred to as optical density, or simply density; the optical density is proportional to the logarithm
Logarithm
The logarithm of a number is the exponent by which another fixed value, the base, has to be raised to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 1000 is 10 to the power 3: More generally, if x = by, then y is the logarithm of x to base b, and is written...
of the optical transmission coefficient
Transmission coefficient
The transmission coefficient is used in physics and electrical engineering when wave propagation in a medium containing discontinuities is considered...
of the developed film. A dark image on the negative is of higher density than a more transparent image.
Most films are affected by the physics of silver grain activation (which sets a minimum amount of light required to expose a single grain) and by the statistics
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
of random grain activation by photons. The film requires a minimum amount of light before it begins to expose, and then responds by progressive darkening over a wide dynamic range of exposure until all of the grains are exposed and the film achieves (after development) its maximum optical density.
Over the active dynamic range of most films, the density of the developed film is proportional to the logarithm of the total amount of light to which the film was exposed, so the transmission coefficient of the developed film is proportional to a power of the reciprocal of the brightness of the original exposure. This is due to the statistics of grain activation: as the film becomes progressively more exposed, each incident photon
Photon
In physics, a photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force...
is less likely to impact a still-unexposed grain, yielding the logarithmic behavior. A simple, idealized statistical model yields the equation , where light is proportional to the number of photons hitting a unit area of film, k is the probability of a single photon striking a grain (based on the size of the grains and how closely spaced they are), and density is the proportion of grains that where hit by at least one photon.
If parts of the image are exposed heavily enough to approach the maximum density possible for a print film, then they will begin losing the ability to show tonal variations in the final print. Usually those areas will be deemed to be overexposed and will appear as featureless white on the print. Some subject matter is tolerant of very heavy exposure; brilliant light sources like a bright light bulb, or the sun, included in the image generally appear best as a featureless white on the print.
Likewise, if part of an image receives less than the beginning threshold level of exposure, which depends upon the film's sensitivity to light—or speed—the film there will have no appreciable image density, and will appear on the print as a featureless black. Some photographers use their knowledge of these limits to determine the optimum exposure for a photograph; for one example, see the Zone System
Zone system
The Zone System is a photographic technique for determining optimal film exposure and development, formulated by Ansel Adams and Fred Archer. Adams described how the Zone System was developed: "I take this opportunity to restate that the Zone System is not an invention of mine; it is a codification...
. Most automatic camera
Camera
A camera is a device that records and stores images. These images may be still photographs or moving images such as videos or movies. The term camera comes from the camera obscura , an early mechanism for projecting images...
s instead try to achieve a particular average density.
Film speed
Hurter and DriffieldHurter and Driffield
Ferdinand Hurter and Vero Charles Driffield were nineteenth-century photographic scientists who brought quantitative scientific practice to photography through the methods of sensitometry and densitometry....
began pioneering work on the light sensitivity
Sensitometry
Sensitometry is the scientific study of light-sensitive materials, especially photographic film. The study has its origins in the work by Ferdinand Hurter and Vero Charles Driffield with early black-and-white emulsions...
of photographic emulsions in 1876. Their work enabled the first quantitative measure of film speed to be devised.
Film speed describes a film's threshold sensitivity to light. The international standard for rating film speed is the ISO scale which combines both the ASA speed and the DIN
Din
DIN or Din or din can have several meanings:* A din is a loud noise.* Dīn, an Arabic term meaning "religion" or "way of life".* Din is one of the ten aspects of the Ein Sof in Kabbalah ....
speed in the format ASA/DIN. Using ISO convention film with an ASA speed of 400 would be labeled 400/27°. A fourth naming standard is GOST
GOST
GOST refers to a set of technical standards maintained by the Euro-Asian Council for Standardization, Metrology and Certification , a regional standards organization operating under the auspices of the Commonwealth of Independent States .All sorts of regulated standards are included, with examples...
, developed by the Russian standards authority. See the film speed
Film speed
Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system....
article for a table of conversions between ASA, DIN, and GOST film speeds.
Common film speeds include ISO 25, 50, 64, 100, 160, 200, 400, 800, 1600, and 3200. Consumer print films are usually in the ISO 100 to ISO 800 range. Some films, like Kodak's Technical Pan
Technical Pan
Technical Pan was an almost panchromatic black-and-white film produced by Kodak. While it could reproduce the visible light spectrum, it leaned to the red, and so unfiltered outdoor shots would render blues, most notably the sky, with additional darkening and reds with some lightening. These unique...
, are not ISO rated and therefore careful examination of the film's properties must be made by the photographer before exposure and development. ISO 25 film is very "slow", as it requires much more exposure
Exposure (photography)
In photography, exposure is the total amount of light allowed to fall on the photographic medium during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value and scene luminance over a specified area.In photographic jargon, an exposure...
to produce a usable image than "fast" ISO 800 film. Films of ISO 800 and greater are thus better suited to low-light situations and action shots (where the short exposure time limits the total light received). The benefit of slower film is that it usually has finer grain and better color rendition than fast film. Professional photographers of static subjects such as portraits or landscapes usually seek these qualities, and therefore require a tripod
Tripod
A tripod is a portable three-legged frame, used as a platform for supporting the weight and maintaining the stability of some other object. The word comes from the Greek tripous, meaning "three feet". A tripod provides stability against downward forces, horizontal forces and moments about the...
to stabilize the camera for a longer exposure. Photographing subjects such as rapidly moving sports or in low-light conditions, a professional will choose a faster film. Grain size refers to the size of the silver crystals in the emulsion. The smaller the crystals, the finer the detail in the photo and the slower the film.
A film with a particular ISO rating can be pushed
Push processing
Push processing in photography, sometimes called uprating, refers to a film developing technique that increases the effective sensitivity of the film being processed. Push processing involves developing the film for more time, possibly in combination with a higher temperature, than the...
to behave like a film with a higher ISO. In order to do this, the film must be developed for a longer amount of time or at a higher temperature than usual. This procedure is usually only performed by photographers who do their own development or professional-level photofinishers. More rarely, a film can be pulled to behave like a "slower" film.
History of film
Early photography in the form of daguerreotypeDaguerreotype
The daguerreotype was the first commercially successful photographic process. The image is a direct positive made in the camera on a silvered copper plate....
s did not use film at all. The light-sensitive chemicals were formed on the surface of a silver-plated copper sheet. Beginning in the 1850s, thin glass plates coated with photographic emulsion
Photographic emulsion
Photographic emulsion is a light-sensitive colloid, such as gelatin, coated onto a substrate. In silver-gelatin photography, the emulsion consists of silver halide crystals suspended in gelatin, and the substrate may be glass, plastic film, paper or fabric....
became the standard medium. Although fragile and heavy, the glass used for photographic plates was of better optical quality than early transparent plastics, and in early years it was also less expensive, so the use of such plates persisted long after the introduction of film. Eastman Kodak
Eastman Kodak
Eastman Kodak Company is a multinational imaging and photographic equipment, materials and services company headquarted in Rochester, New York, United States. It was founded by George Eastman in 1892....
marketed the first flexible photographic roll film in 1885, but this original "film" was actually coated on paper. After exposure, as part of the processing, the image-bearing layer was stripped from the paper base and transferred to a glass support to facilitate printing from it. The first transparent plastic film was produced in 1889. It was made from highly flammable nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
(celluloid
Celluloid
Celluloid is the name of a class of compounds created from nitrocellulose and camphor, plus dyes and other agents. Generally regarded to be the first thermoplastic, it was first created as Parkesine in 1862 and as Xylonite in 1869, before being registered as Celluloid in 1870. Celluloid is...
), now commonly known as "nitrate film". Although cellulose acetate
Cellulose acetate
Cellulose acetate , first prepared in 1865, is the acetate ester of cellulose. Cellulose acetate is used as a film base in photography, as a component in some adhesives, and as a frame material for eyeglasses; it is also used as a synthetic fiber and in the manufacture of cigarette filters and...
or "safety film" had been introduced by Kodak in 1908, it was not until the 1920s that it began to significantly replace the hazardous nitrate film, which had the advantages of being considerably tougher, slightly more transparent, and cheaper. The changeover was not completed for X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
films until 1933, and although safety film was always used for 16mm and 8mm home movies, nitrate film remained standard for theatrical 35mm motion pictures until it was finally discontinued in 1951.
Spectral sensitivity
Early photographic plates and films were usefully sensitive only to blue, violet and ultraviolet lightLight
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
. In 1873, Hermann Wilhelm Vogel discovered that the spectral sensitivity
Spectral sensitivity
Spectral sensitivity is the relative efficiency of detection, of light or other signal, as a function of the frequency or wavelength of the signal....
could be extended by adding very small quantities of certain dyes to the emulsion. The instability of early sensitizing dyes and their tendency to rapidly cause fogging
Fogging (photography)
Fogging in photography is the deterioration in the quality of the image caused either by extraneous light or the effects of a processing chemical.-Taxonomy of fogging:...
initially confined their use to the laboratory, but in 1883 the first commercially dye-sensitized plates appeared on the market. These early products, described as isochromatic or orthochromatic
Orthochromatic
- Orthochromatic photography :Orthochromatic photography refers to a photographic emulsion that is sensitive to only blue and green light, and thus can be processed with a red safelight. The increased blue sensitivity causes blue objects to appear lighter and red ones darker...
depending on the manufacturer, were also significantly sensitive to green and yellow, making possible a more accurate rendering of colored subject matter into a black-and-white image. Because they were still disproportionately sensitive to blue, the use of a yellow filter and a consequently longer exposure time were required in order to make full use of their extended sensitivity. In 1894 the Lumière Brothers introduced their Lumière Panchromatic plate, which was made sensitive, although very unequally, to all colors including red. New and improved sensitizing dyes were developed, and by 1902 the much more evenly color-sensitive Perchromo panchromatic plate was being sold by the German manufacturer Perutz. However, all of these were glass-based plate products. Panchromatic
Panchromatic
Panchromatic film is a type of black-and-white photographic film that is sensitive to all wavelengths of visible light. A panchromatic film therefore produces a realistic reproduction of a scene as it appears to the human eye. Almost all modern photographic film is panchromatic, but some types are...
emulsions on a film base were not commercially available until the 1910s and did not come into general use until much later. In part, this was because many photographers who did their own darkroom work preferred to go without the seeming luxury of sensitivity to red—a rare color in nature and uncommon even in man-made objects—rather than be forced to abandon the traditional red darkroom
Darkroom
A darkroom is a room that can be made completely dark to allow the processing of light sensitive photographic materials, including photographic film and photographic paper. Darkrooms have been created and used since the inception of photography in the early 19th century...
safelight
Safelight
A safelight is a light source suitable for use in a photographic darkroom. It provides illumination only from parts of the visible spectrum to which the photographic material in use is nearly or completely insensitive.- Design :...
and process their exposed film in complete darkness. Kodak's popular Verichrome black-and-white snapshot film, introduced in 1931, remained a red-insensitive orthochromatic product until 1956, when it was replaced by Verichrome Pan. Amateur darkroom enthusiasts then had no option but to handle undeveloped film by the sense of touch alone.
Color
Experiments with color photographyColor photography
Color photography is photography that uses media capable of representing colors, which are traditionally produced chemically during the photographic processing phase...
began almost as early as photography itself, but the three-color principle underlying all practical processes was not set forth until 1855, not demonstrated until 1861, and not generally accepted as "real" color photography until it had become an undeniable commercial reality in the early 20th century. Although color photographs of good quality were being made by the 1890s, they required special equipment, long exposures, complex printing or display procedures and highly specialized skills, so they were then exceedingly rare. The first easily used and commercially successful color "film" was the Lumière Autochrome, a glass plate product introduced in 1907. It was expensive and not sensitive enough for hand-held "snapshot" use. Film-based versions were introduced in the early 1930s and sensitivity was improved, but "color film" in the modern sense was born with the introduction of Kodachrome
Kodachrome
Kodachrome is the trademarked brand name of a type of color reversal film that was manufactured by Eastman Kodak from 1935 to 2009.-Background:...
for home movies in 1935 and as lengths of 35mm film for still cameras in 1936. During the next several decades, color remained much more expensive than black-and-white and required much more light, factors which combined to delay its widespread adoption. Decreasing cost and increasing sensitivity gradually overcame these impediments. By the 1970s color film predominated and the use of black-and-white film was increasingly confined to low-light and "art" photography and other niche applications.
Effect on lens and equipment design
Photographic lenses and equipment are designed around the film to be used. Although the earliest photographic materials were sensitive only to the blue-violet end of the spectrumVisible spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm. In terms of...
, partially color-corrected achromatic lens
Achromatic lens
An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths into focus in the same plane....
es were normally used, so that when the photographer brought the visually brightest yellow rays to a sharp focus, the visually dimmest but photographically most active violet rays would be correctly focused, too. The introduction of orthochromatic emulsions required the whole range of colors from yellow to blue to be brought to an adequate focus. Most plates and films described as orthochromatic or isochromatic were practically insensitive to red, so the correct focus of red light was unimportant; a red window could be used to view the frame numbers on the paper backing of roll film, as any red light which leaked around the backing would not fog the film; and red lighting could be used in darkroom
Darkroom
A darkroom is a room that can be made completely dark to allow the processing of light sensitive photographic materials, including photographic film and photographic paper. Darkrooms have been created and used since the inception of photography in the early 19th century...
s. With the introduction of panchromatic film the whole visible spectrum needed to be brought to an acceptably sharp focus. In all cases a color cast in the lens glass or faint colored reflections in the image were of no consequence as they would merely change the contrast a little. This was no longer acceptable when using color film. More highly corrected lenses for newer emulsions could be used with older emulsion types, but the converse was not true.
The progression of lens design for later emulsions is of practical importance when considering the use of old lenses, still often used on large-format equipment; a lens designed for orthochromatic film may have visible defects with a color emulsion; a lens for panchromatic film will be better but not as good as later designs.
The filters
Photographic filter
In photography and videography, a filter is a camera accessory consisting of an optical filter that can be inserted in the optical path. The filter can be a square or oblong shape mounted in a holder accessory, or, more commonly, a glass or plastic disk with a metal or plastic ring frame, which...
used were different for the different film types.
Special films
Instant photography, as popularised by PolaroidPolaroid Corporation
Polaroid Corporation is an American-based international consumer electronics and eyewear company, originally founded in 1937 by Edwin H. Land. It is most famous for its instant film cameras, which reached the market in 1948, and continued to be the company's flagship product line until the February...
, uses a special type of camera and film that automates and integrates development, without the need of further equipment or chemicals. This process is carried out immediately after exposure, as opposed to regular film, which is developed afterwards and requires additional chemicals. See instant film
Instant film
Instant film is a type of photographic film first introduced by Polaroid that is designed to be used in an instant camera...
.
Films can be made to record non-visible ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
(UV) and infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
(IR) radiation
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
. These films generally require special equipment; for example, most photographic lens
Photographic lens
A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.While in principle a simple convex lens will suffice, in...
es are made of glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
and will therefore filter out most ultraviolet light. Instead, expensive lenses made of quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
must be used. Infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
films may be shot in standard cameras using an infrared band- or long-pass filter
Filter (optics)
Optical filters are devices which selectively transmit light of different wavelengths, usually implemented as plane glass or plastic devices in the optical path which are either dyed in the mass or have interference coatings....
, although the infrared focal point must be compensated for.
Exposure and focusing are difficult when using UV or IR film with a camera and lens designed for visible light. The ISO standard for film speed only applies to visible light, so visual-spectrum light meters are nearly useless. Film manufacturers can supply suggested equivalent film speeds under different conditions, and recommend heavy bracketing
Bracketing
In photography, bracketing is the general technique of taking several shots of the same subject using different or the same camera settings. Bracketing is useful and often recommended in situations that make it difficult to obtain a satisfactory image with a single shot, especially when a small...
. e.g. with a certain filter, assume ISO 25 under daylight and ISO 64 under tungsten lighting. This allows a light meter to be used to estimate an exposure. The focal point for IR is slightly farther away from the camera than visible light, and UV slightly closer; this must be compensated for when focusing. Apochromat
Apochromat
An apochromat, or apochromatic lens , is a photographic or other lens that has better correction of chromatic and spherical aberration than the much more common achromat lenses.-Explanation:...
ic lenses are sometimes recommended due to their improved focusing across the spectrum.
Film optimized for sensing X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
radiation is commonly used for medical imaging
Medical imaging
Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...
by placing the subject between the film and a source of X-rays, without a lens, as if a translucent object were imaged by being placed between a light source and standard film.
Film optimized for sensing X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s and for gamma rays is sometimes used for radiation dosimetry
Dosimetry
Radiation dosimetry is the measurement and calculation of the absorbed dose in matter and tissue resulting from the exposure to indirect and direct ionizing radiation...
and personal monitoring.
Film has a number of disadvantages as a scientific detector: it is difficult to calibrate for photometry
Photometry (optics)
Photometry is the science of the measurement of light, in terms of its perceived brightness to the human eye. It is distinct from radiometry, which is the science of measurement of radiant energy in terms of absolute power; rather, in photometry, the radiant power at each wavelength is weighted by...
, it is not re-usable, it requires careful handling (including temperature and humidity control) for best calibration, and the film must physically be returned to the laboratory and processed. Against this, photographic film can be made with a higher spatial resolution than any other type of imaging detector, and, because of its logarithmic response to light, has a wider dynamic range than most digital detectors. For example, Agfa 10E56 holographic film has a resolution of over 4,000 lines/mm—equivalent to a pixel size of 0.125 micrometres—and an active dynamic range of over five orders of magnitude in brightness, compared to typical scientific CCD
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
s that might have pixels of about 10 micrometres and a dynamic range of 3-4 orders of magnitude.
Special films are used for the long exposures required by astrophotography
Astrophotography
Astrophotography is a specialized type of photography that entails recording images of astronomical objects and large areas of the night sky. The first photographs of an astronomical object were taken in the 1840s, but it was not until the late 19th century that advances in technology allowed for...
.
Common sizes of film
- 135135 filmThe term 135 was introduced by Kodak in 1934 as a designation for cartridge film wide, specifically for still photography. It quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film format...
— "35 mm" - IX240Advanced Photo SystemAdvanced Photo System is a 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 AgfaPhoto under the name Futura and by Konica as Centuria.- Design :The film is 24 mm wide, and has three...
— APS (Advanced Photo System) or "Advantix" - 110110 film110 is a cartridge-based film format used in still photography. It was introduced by Kodak in 1972. 110 is a miniaturised version of Kodak's earlier 126 film format. Each frame is , with one registration hole....
- 126126 film126 is the number given to a cartridge-based film format used in still photography. It was introduced by Kodak in 1963, and is associated mainly with low-end point-and-shoot cameras, particularly Kodak's own Instamatic series of cameras....
- 127127 film127 is a film format for still photography. The image format is usually a square 4×4 cm, but rectangular 4×3 cm and 4×6 cm are also standard. Oddly, C. F. Foth & Co. used 36×24 mm for its first “Derby” model....
- 120120 film120 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...
/220 — for use in medium formatMedium formatMedium format has traditionally referred to a film format in still photography and the related cameras and equipment that use that film. Generally, the term applies to film and digital cameras that record images on media larger than 24 by 36 mm , but smaller than 4 by 5 inches .In digital...
photography - Sheet filmSheet filmSheet film is large format and medium format photographic film supplied on individual sheets of acetate or polyester film base rather than rolls. Sheet film was initially supplied as an alternative to glass plates...
— for use in large formatLarge formatLarge format refers to any imaging format of 4×5 inches or larger. Large format is larger than "medium format", the 6×6 cm or 6×9 cm size of Hasselblad, Rollei, Kowa, Pentax etc cameras , and much larger than the 24×36 mm frame of 35 mm format.The main advantage...
photography - Disc filmDisc filmthumb|Cartridge of disc filmDisc film was a still-photography film format aimed at the consumer market, and introduced by Kodak in 1982.The film was in the form of a flat disc, and was fully housed within a plastic cartridge...
— obsolete format used in disc system cameras - Motion picture filmsFilm stockFilm stock is photographic film on which filmmaking of motion pictures are shot and reproduced. The equivalent in television production is video tape.-1889–1899:...
— 8 mm, 16 mm, 35 mm and 70 mm
Companies
- * - discontinued, ** - bankruptcy, *** - retail existing stock, production limited, **** - reseller, no manufacturing plant
- AgfaPhotoAgfaPhotoAgfaPhoto GmbH is a European photographic company, formed in 2004 when Agfa-Gevaert sold their Consumer Imaging division. Agfa had for many years been well known as a producer of consumer-oriented photographic products including films, photographic papers and cameras...
** - Agfa-GevaertAgfa-GevaertAgfa-Gevaert N.V. is a European multinational corporation that develops, manufactures, and distributes analogue and digital imaging products and systems, as well as IT solutions. The company has three divisions. Agfa Graphics offers integrated prepress and industrial inkjet systems to the...
(Materials division) - BerggerBerggerThe Bergger company was begun over a century ago by French manufacturer Guilleminot. The company manufactures monochrome photographic film 35mm to 20"x24" as well as photographic paper and chemicals....
(European company composed of former Guilleminot employees.)**** - Dai Nippon Printing
- EfkeEfkeEfke is the brand name of photographic films, papers, and chemicals manufactured by Fotokemika d.d., a company located in Samobor, Croatia.-Products description:...
- FomaFomaFoma may refer to:* FOMA , a Japanese mobile telecommunications service* Sergei Fomenko, nicknamed "Foma", Ukrainian musician...
- Forte**
- FerraniaFerraniaFerrania S.p.A. is a manufacturing company located in Ferrania , Italy.The original firm was started in 1923 as a maker of photographic films, papers, and equipment. The company was purchased in 1964 by the 3M company, who spun it off to their Imation Division. The firm was acquired by Schroder...
- FujifilmFujifilmis a multinational photography and imaging company headquartered in Tokyo, Japan.Fujifilm's principal activities are the development, production, sale and servicing of color photographic film, digital cameras, photofinishing equipment, color paper, photofinishing chemicals, medical imaging...
- IlfordIlford PhotoIlford Photo is a manufacturer of photographic materials known worldwide for its black-and-white film and papers and chemicals, as well as its range of Ilfochrome and Ilfocolor colour printing materials. Ilfochrome was formerly called Cibachrome, developed in partnership with the Swiss company...
- ImationImationImation is a US based multi-national technology corporation that designs, manufactures and sells recordable data storage media, consumer electronics products and accessories.The company is a 1996 spin off of 3M and is headquartered in Oakdale, Minnesota...
(film division purchased by Ferrania) - KodakEastman KodakEastman Kodak Company is a multinational imaging and photographic equipment, materials and services company headquarted in Rochester, New York, United States. It was founded by George Eastman in 1892....
- Konica MinoltaKonica Minoltais a Japanese manufacturer of office equipment, medical imaging, graphic imaging, optical devices, and measuring instruments. It is headquartered in the Marunouchi Center Building in Marunouchi, Chiyoda, Tokyo, with a Kansai office in Nishi-ku, Osaka, Osaka Prefecture...
* - LuckyChina Lucky FilmChina Lucky Film Corporation is the largest photosensitive materials and magnetic recording media manufacturer in Baoding, Hebei province, China.-History:...
- MacoMaco (film company)Maco is a Germany based supplier of photographic films including old 127 size film....
**** - MitsubishiMitsubishiThe Mitsubishi Group , Mitsubishi Group of Companies, or Mitsubishi Companies is a Japanese multinational conglomerate company that consists of a range of autonomous businesses which share the Mitsubishi brand, trademark and legacy...
- ORWOORWOORWO was an East German manufacturer of photographic film and magnetic tape. The basis for ORWO was the Agfa Wolfen plant, where the first modern colour film with incorporated colour couplers, Agfacolor, was developed in 1936....
- Perutz*
- PolaroidPolaroid CorporationPolaroid Corporation is an American-based international consumer electronics and eyewear company, originally founded in 1937 by Edwin H. Land. It is most famous for its instant film cameras, which reached the market in 1948, and continued to be the company's flagship product line until the February...
*** - ProClick
- Rollei
- Shanghai (SMPIC Photosensitive Materials Factory)
- Solaris (owned by Ferrania)
- SvemaSvemaSvema is a registered trade mark and former name of the Shostka Chemical Plant, located in Shostka, Sumy Oblast, Ukraine. It was founded in 1931 in then Ukrainian SSR....
* - Tasma*
- Tura**
Film manufacturers commonly make film that is branded by other companies. Modern films have bar codes (DX code
DX encoding
DX encoding is an ANSI and I3A standard, originally introduced by Kodak in March 1983, for marking 135 and APS photographic film and film cartridges...
s) on the edge of the film which can be read by a bar code reader. This is because film is sometimes processed differently according to specifications of the film, determined by its manufacturer; the bar code is entered into the computer printer before the film is printed.
To establish the OEM
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
, read the bar code printed on the cassette. Divide the long number by 16 and record the number before the decimal, then multiply the number after the decimal by 16, this could give you a result such as 18 and 2.
The first number is known as the PRODUCT (film manufacturer) and the second number as the MULTIPLIER (speed of the film ISO). In the previous example, 18 identifies 3M as the manufacturer and 2 means it is 200 ISO:
- 3M = 18
- Agfa = 17 or 49
- Kodak = 80, 81, 82 or 88
See also
- APUGAPUGAPUG is the Analog Photography Users Group,a website and internet forum for an international group of photographers who use analog photography. The website was founded in September 2002, and has attracted approximately 50,000 members, including paying subscribers...
- List of photographic equipment makers
- List of photographic films
- SensitometrySensitometrySensitometry is the scientific study of light-sensitive materials, especially photographic film. The study has its origins in the work by Ferdinand Hurter and Vero Charles Driffield with early black-and-white emulsions...
External links
- APUG (traditional photography 'analog' forums)
- British Journal of Photography