TheInfoList

Photographic film is a strip or sheet of transparent
film baseA film base is a transparent substrate which acts as a support medium for the photosensitive emulsion An emulsion is a mixture of two or more liquids that are normally Miscibility, immiscible (unmixable or unblendable) owing to liquid-liquid pha ...
coated on one side with a
gelatin Gelatin or gelatine (from la, gelatus meaning "stiff" or "frozen") is a translucent, colorless, flavorless food ingredient, commonly derived from collagen upright=1.5, Tropocollagen molecule: three left-handed procollagens (red, green, blue) j ...
emulsion An emulsion is a mixture of two or more liquids that are normally Miscibility, immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloid ...
containing microscopically small light-sensitive
silver halide A silver halide (or silver salt) is one of the chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entity, molecular entities) composed of atoms from more than one chemical element, e ...
crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and
resolution Resolution(s) may refer to: Common meanings * Resolution (debate), the statement which is debated in policy debate * Resolution (law), a written motion adopted by a deliberative body * New Year's resolution, a commitment that an individual make ...
of the film. The emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a very short exposure to the image formed by a
camera A camera is an optical Optics is the branch of physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and t ...

lens is used to produce only a very slight chemical change, proportional to the amount of light absorbed by each crystal. This creates an invisible
latent image {{citations needed, date=November 2015 A latent image is an invisible image produced by the exposure to light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be visual perception ...

in the emulsion, which can be chemically
developed Development or developing may refer to: Arts *Development hell, when a project is stuck in development *Filmmaking#Development, Filmmaking, development phase, including finance and budgeting *Development (music), the process thematic material i ...

into a visible
photograph A photograph (also known as a photo) is an image An SAR radar image acquired by the SIR-C/X-SAR radar on board the Space Shuttle Endeavour shows the Teide volcano. The city of Santa Cruz de Tenerife is visible as the purple and white ...
. In addition to visible light, all films are sensitive to
ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that stud ...

light,
X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 Picometre, picometers to 10 Nanometre, nanometers, corresponding to frequency ...

s and
gamma ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, it ...
s, and high-energy particles. Unmodified silver halide crystals are sensitive only to the blue part of the visible spectrum, producing unnatural-looking renditions of some colored subjects. This problem was resolved with the discovery that certain dyes, called sensitizing dyes, when
adsorbed of multilayer adsorption is a random distribution of molecules on the material surface. Adsorption is the adhesion of atoms An atom is the smallest unit of ordinary matter that forms a chemical element Image:Simple Periodic Table Char ...
onto the silver halide crystals made them respond to other colors as well. First
orthochromatic In chemistry, orthochromasia is the property of a staining, dye or stain to not change color on binding to a target, as opposed to Metachromasia, metachromatic stains, which change color. The word is derived from the Greek ''wikt:ortho-, orthos'' ( ...
(sensitive to blue and green) and finally
panchromatic Panchromatic emulsion is a type of black-and-white photographic emulsion that is sensitive to all wavelengths of visible light. Description A panchromatic emulsion produces a realistic reproduction of a scene as it appears to the human eye, alt ...
(sensitive to all visible colors) films were developed.
Panchromatic Panchromatic emulsion is a type of black-and-white photographic emulsion that is sensitive to all wavelengths of visible light. Description A panchromatic emulsion produces a realistic reproduction of a scene as it appears to the human eye, alt ...
film renders all colors in shades of gray approximately matching their subjective brightness. By similar techniques, special-purpose films can be made sensitive to the
infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...

(IR) region of the
spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a Continuum (theory), continuum. The word was first used scientifically in optics to describe the ...

. In black-and-white photographic film, there is usually one layer of silver halide crystals. When the exposed silver halide grains are developed, the silver halide crystals are converted to metallic silver, which blocks light and appears as the black part of the film negative. Color film has at least three sensitive layers, incorporating different combinations of sensitizing dyes. Typically the blue-sensitive layer is on top, followed by a yellow filter layer to stop any remaining blue light from affecting the layers below. Next comes a green-and-blue sensitive layer, and a red-and-blue sensitive layer, which record the green and red images respectively. During development, the exposed silver halide crystals 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 A dye is a color Color (American English) or colour (Commonwealth English) is the visual perception, visual perceptual Physical property, property corresponding in humans to the categories called ''blue'', ''green'', ''red'', etc. Colo ...
clouds formed are also in proportion to the exposure and development. Following development, the silver is converted back to silver halide crystals in the ''bleach step''. It is removed from the film during the process of ''fixing'' the image on the film with a solution of ammonium thiosulfate or sodium thiosulfate (hypo or fixer). Fixing leaves behind only the formed color dyes, which combine to make up the colored visible image. Later color films, like Kodacolor II, have as many as 12 emulsion layers, with upwards of 20 different chemicals in each layer. Photographic film and
film stock Film stock is an that is used for recording or . It is recorded on by a , , , and projected onto a screen using a . It is a strip or sheet of transparent coated on one side with a containing microscopically small light-sensitive cry ...
tend to be similar in composition and speed, but often not in other parameters such as frame size and length. Silver halide
photographic paper Photographic paper is a coated paper, paper coated with a light-sensitive chemical formula, like photographic film, used for making photographic prints. When photographic paper is exposed to light, it captures a latent image that is then Film devel ...
is also similar to photographic film.

# Characteristics of film

## Film basics

There are several types of photographic film, including: *Print film, when developed, yields transparent negatives with the light and dark areas and colors (if color film is used) inverted to their respective
complementary colors Complementary colors are pairs of color Color ( American English), or colour ( Commonwealth English), is the characteristic of visual perception described through color ''categories'', with names such as red, orange (colour), orange, ...
. This type of film is designed to be printed onto
photographic paper Photographic paper is a coated paper, paper coated with a light-sensitive chemical formula, like photographic film, used for making photographic prints. When photographic paper is exposed to light, it captures a latent image that is then Film devel ...
, usually by means of an
enlarger An enlarger is a specialized transparency projector image:IFA 2012 IMG 5767.JPG, 200px, Acer inc., Acer projector, 2012 A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a proj ...
but in some cases by
contact print A contact print is a photographic image produced from Photographic film, film; sometimes from a film negative (photography), negative, and sometimes from a film positive or paper negative. In a darkroom an exposed and developed piece of film or p ...

ing. The paper is then itself developed. The second inversion that results restores light, shade and color to their normal appearance. Color negatives incorporate an orange color correction mask that compensates for unwanted dye absorptions and improves color accuracy in the prints. Although color processing is more complex and temperature-sensitive than black-and-white processing, the wide availability of commercial color processing and scarcity of service for black-and-white prompted the design of some black-and-white films which are processed in exactly the same way as standard color film. * Color reversal film produces positive
transparencies Image:OHP-sch.JPG, 300px, Overhead projector in operation, with a transparency being flashed A transparency, also known variously as a viewfoil, foil, or viewgraph, is a thin sheet of transparency (optics), transparent flexible material, typically ...
, also known as diapositives. Transparencies can be reviewed with the aid of a magnifying
loupe A loupe ( ) is a simple, small magnification Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a calculated number also called "magnification". When this number is l ...

and a
lightbox A lightbox is a translucent surface illuminated from behind, used for situations where a shape laid upon the surface needs to be seen with high contrast. Types File:Louisa lawson suffragette light box memorial greenway.JPG, Lightbox used as a M ...

. If mounted in small metal, plastic or cardboard frames for use in a
slide projector A slide projector is an opto-mechanical device for showing photographic slides. 35 mm slide projectors, direct descendants of the larger-format magic lantern The magic lantern, also known by its Latin name ''laterna magica'', is a ...

or slide viewer they are commonly called slides. Reversal film is often marketed as "slide film". color reversal
sheet film Sheet film is large format Large format refers to any imaging format of 9×12 cm (3-1/2x4-3/4 inch) or larger. Large format is larger than "medium format", the 6×6 cm (2¼×2¼ inch) or 6×9 cm (2¼×3½ inch) size of Hassel ...
is used by some professional photographers, typically to originate very-high-resolution imagery for digital scanning into
color separation Color printing or colour printing is the reproduction of an image or text in color (as opposed to simpler black and white or monochrome during the 1889 Exposition Universelle rendered with a monochrome palette of a limited number of sha ...
s for mass
photomechanical reproduction Halftone is the reprographic technique that simulates continuous tone, continuous-tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect.Campbell, Alastair. The Designer's Lexicon. ©2000 ...
. Photographic prints can be produced from reversal film transparencies, but positive-to-positive print materials for doing this directly (e.g. Ektachrome paper, Cibachrome/Ilfochrome) have all been discontinued, so it now requires the use of an internegative to convert the positive transparency image into a negative transparency, which is then printed as a positive print. *Black-and-white reversal film exists but is very uncommon. Conventional black-and-white negative film can be reversal-processed to produce black-and-white slides, as by
dr5 Chrome dr5, or dr5 Chrome, is a reversal black and white Black-and-white (B/W or B&W) images combine black and white in a continuous spectrum In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), kn ...
. Although kits of chemicals for black-and-white reversal processing may no longer be available to amateur darkroom enthusiasts, an acid bleaching solution, the only unusual component which is essential, is easily prepared from scratch. Black-and-white transparencies may also be produced by printing negatives onto special positive print film, still available from some specialty photographic supply dealers. In order to produce a usable image, the film needs to be exposed 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 halide crystals remaining on the film after development is referred to as
optical density In optics Optics is the branch of physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (physic ...
, or simply
density The density (more precisely, the volumetric mass density; also known as specific mass), of a substance is its per unit . The symbol most often used for density is ''ρ'' (the lower case Greek letter ), although the Latin letter ''D'' can also ...

; the optical density is proportional to the
logarithm In mathematics Mathematics (from Greek: ) includes the study of such topics as numbers ( and ), formulas and related structures (), shapes and spaces in which they are contained (), and quantities and their changes ( and ). There is no ...

of the optical
transmission coefficient The transmission coefficient is used in physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and time, and the re ...
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 is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data Data (; ) are individual facts, statistics, or items of information, often numeric. In a more technical sens ...

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 Dynamic range (abbreviated DR, DNR, or DYR) is the ratio In mathematics, a ratio indicates how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemon ...
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 Power most often refers to: * Power (physics) In physics, power is the amount of energy In , energy is the that must be to a or to perform on the body, or to it. Energy is a ; the law of states that energy can be in form, bu ...
of the
reciprocal Reciprocal may refer to: In mathematics * Multiplicative inverse, in mathematics, the number 1/''x'', which multiplied by ''x'' gives the product 1, also known as a ''reciprocal'' * Reciprocal polynomial, a polynomial obtained from another poly ...
of the brightness of the original exposure. The plot of the density of the film image against the log of the exposure is known as an H&D curve. This effect is due to the statistics of grain activation: as the film becomes progressively more exposed, each incident
photon The photon ( el, φῶς, phōs, light) is a type of elementary particle In , an elementary particle or fundamental particle is a that is not composed of other particles. Particles currently thought to be elementary include the fundamental s ...

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 have been hit by at least one photon. The relationship between density and log exposure is linear for photographic films except at the extreme ranges of maximum exposure (D-max) and minimum exposure (D-min) on an H&D curve, so the curve is characteristically S-shaped (as opposed to digital camera sensors which have a linear response through the effective exposure range). The sensitivity (i.e., the ISO speed) of a film can be affected by changing the length or temperature of development, which would move the H&D curve to the left or right (''see figure''). 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 considered overexposed and will appear as featureless white on the print. Some subject matter is tolerant of very heavy exposure. For example, sources of brilliant light, such as a light bulb or the sun, 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. Most automatic cameras instead try to achieve a particular average density. Color films can have many layers. The film base can have an antihalation layer applied to it or be dyed. This layer prevents light from reflecting from within the film, increasing image quality. If applied to the back of the film, it also serves to prevent scratching, as an antistatic measure due to its conductive carbon content, and as a lubricant to help transport the film through mechanisms. The antistatic property is necessary to prevent the film from getting fogged under low humidity, and mechanisms to avoid static are present in most if not all films. If applied on the back it is removed during film processing. If applied it may be on the back of the film base in triacetate film bases or in the front in PET film bases, below the emulsion stack. An anticurl layer and a separate antistatic layer may be present in thin high resolution films that have the antihalation layer below the emulsion. PET film bases are often dyed, specially because PET can serve as a light pipe; black and white film bases tend to have a higher level of dying applied to them. The film base needs to be transparent but with some density, perfectly flat, insensitive to light, chemically stable, resistant to tearing and strong enough to be handled manually and by camera mechanisms and film processing equipment, while being chemically resistant to moisture and the chemicals used during processing without losing strength, flexibility or changing in size. The subbing layer is essentially an adhesive that allows the subsequent layers to stick to the film base. The film base was initially made of highly flammable cellulose nitrate, which was replaced by
cellulose acetate film Cellulose acetate film, or safety film, is used in 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 ligh ...
s, often cellulose triacetate film (safety film), which in turn was replaced in many films (such as all print films, most duplication films and some other specialty films) by a PET (polyethylene terephthalate) plastic film base. Films with a triacetate base can suffer from vinegar syndrome, a decomposition process accelerated by warm and humid conditions, that releases acetic acid which is the characteristic component of vinegar, imparting the film a strong vinegar smell and possibly even damaging surrounding metal and films. Films are usually spliced using a special adhesive tape; those with PET layers can be ultrasonically spliced or their ends melted and then spliced. The emulsion layers of films are made by dissolving pure silver in nitric acid to form silver nitrate crystals, which are mixed with other chemicals to form silver halide grains, which are then suspended in gelatin and applied to the film base. The size and hence the light sensitivity of these grains determines the speed of the film; since films contain real silver (as silver halide), faster films with larger crystals are more expensive and potentially subject to variations in the price of silver metal. Also, faster films have more grain, since the grains (crystals) are larger. Each crystal is often 0.2 to 2 microns in size; in color films, the dye clouds that form around the silver halide crystals are often 25 microns across. The crystals can be shaped as cubes, flat rectangles, tetradecadedra, flat hexagons or be flat and resemble a triangle with or without clipped edges; this type of crystal is known as a T-grain crystal. Films using T-grains are more sensitive to light without using more silver halide since they increase the surface area exposed to light by making the crystals flatter and larger in footprint instead of simply increasing their volume.https://www.kodak.com/uploadedfiles/motion/US_plugins_acrobat_en_motion_education_kodak_color_films.pdf The exact silver halide used is either
silver bromide Silver bromide (AgBr) is a soft, pale-yellow, water-insoluble salt well known (along with other silver halides) for its unusual photosensitive, sensitivity to light. This property has allowed silver halides to become the basis of modern photograph ...
or silver bromochloroiodide, or a combination of silver bromide, chloride and iodide. In color films, each emulsion layer has a different color dye forming coupler: in the blue sensitive layer, the coupler forms a yellow dye; in the green sensitive layer the coupler forms a magenta dye, and in the red sensitive layer the coupler forms a cyan dye. Color films often have an UV blocking layer. Each emulsion layer in a color film may itself have three layers: a slow, medium and fast layer, to allow the film to capture higher contrast images. The color
dye coupler Dye coupler is present in chromogenic film A film, also called a movie, motion picture or moving picture, is a work of visual art used to simulate experiences that communicate ideas, stories, perceptions, feelings, beauty, or atmosphere ...
s are inside oil droplets dispersed in the emulsion around silver halide crystals, forming a silver halide grain. Here the oil droplets act as a
surfactant Surfactants are compounds that lower the surface tension Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than wate ...

, also protecting the couplers from chemical reactions with the silver halide and from the surrounding gelatin. During development, oxidized developer diffuses into the oil droplets and combines with the dye couplers to form dye clouds; the dye clouds only form around unexposed silver halide crystals. The fixer then removes the silver halide crystals leaving only the dye clouds: this means that developed color films may not contain silver while undeveloped films do contain silver; this also means that the fixer can start to contain silver which can then be removed through electrolysis. Color films also contain light filters to filter out certain colors as the light passes through the film: often there is a blue light filter between the blue and green sensitive layers and a yellow filter before the red sensitive layer; in this way each layer is made sensitive to only a certain color of light. The color couplers may be colorless and be
chromogenic The term chromogen is applied in chemistry to a colourless (or weakly coloured) chemical compound that can be converted by chemical reaction into a compound which can be described as "coloured". There is no universally agreed definition of the term ...
or be colored. Colored couplers are used to improve the color reproduction of film. The first coupler which is used in the blue layer remains colorless to allow all light to pass through, but the coupler used in the green layer is colored yellow, and the coupler used in the red layer is light pink. Yellow was chosen to block any remaining blue light from exposing the underlying green and red layers (since yellow can be made from green and red). Each layer should only be sensitive to a single color of light and allow all others to pass through. Because of these colored couplers, the developed film appears orange. Colored couplers mean that corrections through color filters need to be applied to the image before printing. Printing can be carried out by using an optical enlarger, or by scanning the image, correcting it using software and printing it using a digital printer. Kodachrome films have no couplers; the dyes are instead formed by a long sequence of steps, limiting adoption among smaller film processing companies. Black and white films are very simple by comparison, only consisting of silver halide crystals suspended in a gelatin emulsion which sits on a film base with an antihalation back. Many films contain a top supercoat layer to protect the emulsion layers from damage. Some manufacturers manufacture their films with daylight, tungsten (named after the tungsten filament of incandescent and halogen lamps) or fluorescent lighting in mind, recommending the use of lens filters, light meters and test shots in some situations to maintain color balance, or by recommending the division of the ISO value of the film by the distance of the subject from the camera to get an appropriate f-number value to be set in the lens. Examples of Color films are
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 f ...
, often processed using the
K-14 process K-14 was the most recent version of the developing process for Kodak's Kodachrome transparency film before its discontinuation (the last revision having been designated Process K-14M). It superseded previous versions of the Kodachrome process used ...
, Kodacolor,
Ektachrome Ektachrome is a brand name owned 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 headquarte ...
, which is often processed using the
E-6 process The E-6 process (often abbreviated to E-6) is a chromogenic The term chromogen is applied in chemistry to a colourless (or weakly coloured) chemical compound that can be converted by chemical reaction into a compound which can be described as "col ...
and Fujifilm Superia, which is processed using the
C-41 process C-41 is a chromogenic The term chromogen is applied in chemistry Chemistry is the scientific discipline involved with Chemical element, elements and chemical compound, compounds composed of atoms, molecules and ions: their composition, struct ...
. The chemicals and the color dye couplers on the film may vary depending on the process used to develop the film.

## Film speed

Film speed describes a film's threshold sensitivity to light. The international standard for rating film speed is the ISO#ISO scale, which combines both the ASA speed and the DIN 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 (russian: ГОСТ) refers to a set of technical standards Standard may refer to: Flags * Colours, standards and guidons * Standard (flag), a type of flag used for personal identification Norm, convention or requirement * Standard (met ...
, developed by the Russian standards authority. See the
film speed Film speed is the measure of a photographic film Photographic film is a strip or sheet of transparent coated on one side with a containing microscopically small light-sensitive crystals. The sizes and other characteristics of the cryst ...
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, 3200, and 6400. Consumer print films are usually in the ISO 100 to ISO 800 range. Some films, like Kodak's
Technical Pan File:Kodak Technical Pan.jpg, An unused roll of Kodak Technical Pan 35 mm film. Technical Pan is an almost panchromatic black-and-white film that was produced by Kodak. While it can reproduce the visible light spectrum, it leans to the red, and s ...
, 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 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 A grain is a small, hard, dry seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double albu ...
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 A tripod is a portable three-legged frame or stand, used as a platform for supporting the weight In science Science () is a systematic enterprise that Scientific method, builds and organizes knowledge in the form of Testability, test ...
to stabilize the camera for a longer exposure. A professional photographing subjects such as rapidly moving sports or in low-light conditions will inevitably choose a faster film. A film with a particular ISO rating can be push-processed, or "pushed", to behave like a film with a higher ISO, by developing for a longer amount of time or at a higher temperature than usual. More rarely, a film can be "pulled" to behave like a "slower" film. Pushing generally coarsens grain and increases contrast, reducing dynamic range, to the detriment of overall quality. Nevertheless, it can be a useful tradeoff in difficult shooting environments, if the alternative is no usable shot at all.

## Special films

Instant photography, as popularized by Polaroid, 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 film. Instant film is a type 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 c ...
. Films can be made to record non-
visible Visibility is in meteorology, a measure of the distance at which an object or light can be seen. Visibility may also refer to: * Visual perception ** Naked-eye visibility * A measure of turbidity in water quality control * Interferometric visibili ...
ultraviolet (UV) and infrared (IR) radiation. These films generally require special equipment; for example, most
photographic lens A camera lens (also known as photographic lens or photographic objective) is an optical Optics is the branch of physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion ...
glass Glass is a non- crystalline, often transparency and translucency, transparent amorphous solid, that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by ...

and will therefore filter out most ultraviolet light. Instead, expensive lenses made of
quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, ...

must be used. Infrared films may be shot in standard cameras using an infrared band- or long-pass
filters Filter, filtering or filters may refer to: Science and technology Device * Filter (chemistry), a device which separates solids from fluids (liquids or gases) by adding a medium through which only the fluid can pass ** Filter (aquarium), critical ...

, 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 In photography Photography is the art Art is a diverse range of (products of) human activities Humans (''Homo sapiens'') are the most populous and widespread species of primates, characterized by bipedality, opposable thumbs, hai ...
(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 An apochromat, or apochromatic lens (apo), is a Photographic lens, photographic or other Lens (optics), lens that has better correction of chromatic aberration, chromatic and spherical aberration than the much more common achromat lenses. Explana ...

ic lenses are sometimes recommended due to their improved focusing across the spectrum. Film optimized for detecting X-ray radiation is commonly used for
medical radiography Medicine is the art, science Science (from the Latin word ''scientia'', meaning "knowledge") is a systematic enterprise that Scientific method, builds and Taxonomy (general), organizes knowledge in the form of Testability, testable explana ...
and
industrial radiography Industrial radiography is a modality of non-destructive testing that uses ionizing radiation to inspect materials and components with the objective of locating and quantifying defects and degradation in material properties that would lead to the f ...
by placing the subject between the film and a source of X-rays or gamma rays, without a lens, as if a translucent object were imaged by being placed between a light source and standard film. Unlike other types of film, X-ray film has a sensitive emulsion on both sides of the carrier material. This reduces the X-ray exposure for an acceptable image – a desirable feature in medical radiography. The film is usually placed in close contact with
phosphor A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or ...

screen(s) and/or thin lead-foil screen(s), the combination having a higher sensitivity to X-rays. Because film is sensitive to x-rays, its contents may be wiped by airport baggage scanners if the film has a speed higher than 800 ISO. This property is exploited in Film badge dosimeters. Film optimized for detecting X-rays and gamma rays is sometimes used for radiation
dosimetryRadiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by an object, usually the human body. This applies both internally, due to ingested or ...
. Film has a number of disadvantages as a scientific detector: it is difficult to calibrate for
photometryPhotometry can refer to: * Photometry (optics), the science of measurement of visible light in terms of its perceived brightness to human vision * Photometry (astronomy), the measurement of the flux or intensity of an astronomical object's electroma ...
, 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, 10E56 holographic film has a resolution of over 4,000 lines/mm—equivalent to a pixel size of 0.125 micrometers—and an active dynamic range of over five orders of magnitude in brightness, compared to typical scientific CCDs that might have pixels of about 10 micrometers and a dynamic range of 3–4 orders of magnitude. Special films are used for the long exposures required by astrophotography.

Some film cameras have the ability to read
metadata Metadata is "data Data (; ) are individual facts, statistics, or items of information, often numeric. In a more technical sense, data are a set of values of qualitative property, qualitative or quantity, quantitative variable (research), v ...

from the film canister or encode metadata on film negatives.

### Negative imprinting

Negative imprinting is a feature of some film cameras, in which the date,
shutter speed In photography Photography is the art Art is a diverse range of (products of) human activities Humans (''Homo sapiens'') are the most populous and widespread species of primates, characterized by bipedality, opposable thumbs ...

and
aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of ray (optics), rays that come to a focus (optics), focus ...

setting are recorded on the negative directly as the film is exposed. The first known version of this process was patented in the United States in 1975, using to direct the readout of a digital clock and mix it with the light rays coming through the main camera lens. Modern SLR cameras use an imprinter fixed to the back of the camera on the film backing plate. It uses a small
LED An LED An LED A light-emitting diode (LED) is a semiconductor A semiconductor material has an Electrical resistivity and conductivity, electrical conductivity value falling between that of a Electrical conductor, conductor, such as m ...
display for illumination and optics to focus the light onto a specific part of the film. The LED display is exposed on the negative at the same time the picture is taken.
Digital camera A digital camera is a camera A camera is an optical Optics is the branch of physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behav ...

s can often encode all the information in the image file itself. The
Exif Exchangeable image file format (officially Exif, according to JEIDA/JEITA/CIPA specifications) is a standard that specifies the formats for image An image (from la, imago) is an artifact that depicts visual perception Visual pe ...
format is the most commonly used format.

### DX codes

In the 1980s, Kodak developed DX Encoding (from Digital indeX), or
DX coding DX (Digital indeX) encoding is an American National Standards Institute, ANSI and I3A standard, originally introduced by Kodak in March 1983, for marking 135 film, 135 and Advanced Photo System, APS photographic film and film cartridges. It consis ...
, a feature that was eventually adapted by all camera and film manufacturers. DX encoding provides information on both the film cassette and on the film regarding the type of film, number of exposures, speed (ISO/ASA rating) of the film. It consists of three types of identification. First is a
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 and spacings of parallel lines. These barcodes, now commonly referred to as linear or one-dime ...

near the film opening of the cassette, identifying the manufacturer, film type and processing method (''see image below left''). This is used by photofinishing equipment during film processing. The second part is a barcode on the edge of the film (''see image below right''), used also during processing, which indicates the image film type, manufacturer, frame number and synchronizes the position of the frame. The third part of DX coding, known as the DX Camera Auto Sensing (CAS) code, consists of a series of 12 metal contacts on the film cassette, which beginning with cameras manufactured after 1985 could detect the type of film, number of exposures and ISO of the film, and use that information to automatically adjust the camera settings for the speed of the film.

Source:

# History of film

The earliest practical photographic process was the
daguerreotype Daguerreotype (; french: daguerréotype) was the first publicly available photographic Photography is the art, application, and practice of creating durable image An SAR radar imaging, radar image acquired by the SIR-C/X-SAR radar on ...
; it was introduced in 1839 and did not use film. The light-sensitive chemicals were formed on the surface of a silver-plated copper sheet. The
calotype Calotype or talbotype is an early photographic process introduced in 1841 by William Fox Talbot, William Henry Fox Talbot, using paper coated with silver iodide. The term ''calotype'' comes from the Greek language, Greek ' (kalos), "beautiful", ...
process produced paper negatives. Beginning in the 1850s, thin glass plates coated with photographic emulsion became the standard material for use in the camera. Although fragile and relatively heavy, the glass used for
photographic plates photographic plates, 1880 Image:Femme-au-chien neg.jpg, Negative plate Photographic plates preceded photographic film as a capture medium in photography, and were still used in some communities up until the late 20th century. The light-sensitive ...
was of better optical quality than early transparent plastics and was, at first, less expensive. Glass plates continued to be used long after the introduction of film, and were used for
astrophotography Astrophotography, also known as astronomical imaging, is of s, s, and areas of the . The first photograph of an astronomical object (the ) was taken in 1840, but it was not until the late 19th century that advances in technology allowed for deta ...

and
electron micrograph A micrograph or photomicrograph is a photograph 396x396px, '' View from the Window at Le Gras'' (1826 or 1827), by Nicéphore Niépce, the earliest known surviving photograph of a real-world scene, made with a camera obscura A cam ...
y until the early 2000s, when they were supplanted by digital recording methods. Ilford continues to manufacture glass plates for special scientific applications. The first flexible photographic roll film was sold by
George Eastman George may refer to: People * George (given name) George (, ) is a masculine given name derived from the Greek language, Greek Georgios, Geōrgios (; , ). The name gained popularity due to its association with the Christian martyrs, Christian ...
in 1885, but this original "film" was actually a coating on a paper base. As part of the processing, the image-bearing layer was stripped from the paper and attached to a sheet of hardened clear gelatin. The first transparent plastic roll film followed in 1889. It was made from highly flammable . Although
cellulose acetate Cellulose acetate refers to any acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetal image:Simple Periodic Table Chart-en.svg, upright=1.75, Nonmetals (and metalloids ...

or "
safety film Cellulose acetate film, or safety film, is used in photography Photography is the art Art is a diverse range of (products of) human activities Humans (''Homo sapiens'') are the most populous and widespread species of primates, ch ...
" had been introduced by Kodak in 1908, at first it found only a few special applications as an alternative to the hazardous nitrate film, which had the advantages of being considerably tougher, slightly more transparent, and cheaper. The changeover was completed for X-ray films in 1933, but although safety film was always used for 16 mm and 8 mm home movies, nitrate film remained standard for theatrical 35 mm films until it was finally discontinued in 1951.
Hurter and Driffield Ferdinand Hurter Ferdinand Hurter (15 March 1844 – 12 March 1898) was a Swiss (people), Swiss industrial chemist who settled in England. He also carried out research into photography. Early life Ferdinand Hurter was born in Schaffhausen, ...
began pioneering work on the
light sensitivityPhotosensitivity is the amount to which an object reacts upon receiving photons, especially visible light. In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicity. ...
of photographic emulsions in 1876. Their work enabled the first quantitative measure of film speed to be devised. They developed H&D curves, which are specific for each film and paper. These curves plot the photographic density against the log of the exposure, to determine sensitivity or speed of the emulsion and enabling correct exposure.

## Spectral sensitivity

Early photographic plates and films were usefully sensitive only to blue, violet and ultraviolet
light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that is visual perception, perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nan ...

. As a result, the relative tonal values in a scene registered roughly as they would appear if viewed through a piece of deep blue glass. Blue skies with interesting cloud formations photographed as a white blank. Any detail visible in masses of green foliage was due mainly to the colorless surface gloss. Bright yellows and reds appeared nearly black. Most skin tones came out unnaturally dark, and uneven or freckled complexions were exaggerated. Photographers sometimes compensated by adding in skies from separate negatives that had been exposed and processed to optimize the visibility of the clouds, by manually retouching their negatives to adjust problematic tonal values, and by heavily powdering the faces of their portrait sitters. In 1873,
Hermann Wilhelm Vogel Hermann Wilhelm Vogel (26 March 1834 – 17 December 1898) was a Germany, German photochemistry, photochemist and photographer who discovered dye sensitization, which is of great importance to photography. Academic career After finishing schoo ...
discovered that the
spectral sensitivity Spectral sensitivity is the relative efficiency of detection, of light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be visual perception, perceived by the human eye. Visible ...
could be extended to green and yellow light by adding very small quantities of certain dyes to the emulsion. The instability of early sensitizing dyes and their tendency to rapidly cause 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'' depending on the manufacturer, made 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 to take full advantage of their extended sensitivity. In 1894, the
Lumière Brothers Lumière is French for 'light'. Lumiere, Lumière or Lumieres may refer to: *Lumières, the philosophical movement in the Age of Enlightenment People *Auguste and Louis Lumière, French pioneers in film-making Film and TV * Institut Lumière, a F ...
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 in 1902 the much more evenly color-sensitive Perchromo panchromatic plate was being sold by the German manufacturer . The commercial availability of highly panchromatic black-and-white emulsions also accelerated the progress of practical color photography, which requires good sensitivity to all the colors of the
spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum Continuum may refer to: * Continuum (measurement) Continuum theories or models expla ...
for the red, green and blue channels of color information to all be captured with reasonable exposure times. However, all of these were glass-based plate products. Panchromatic emulsions on a film base were not commercially available until the 1910s and did not come into general use until much later. 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 A darkroom is used to process , to make and to carry out other associated tasks. It is a room that can be made completely dark to allow the processing of the -sensitive photographic materials, including film and . Various equipment is used in ...

safelight A safelight is a light source Light or visible light is electromagnetic radiation In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , i ...
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 to handle the undeveloped film by the sense of touch alone.

## Introduction to color

Experiments with
color photography Color photography is photography Photography is the art Art is a diverse range of (products of) human activities Humans (''Homo sapiens'') are the most populous and widespread species of primates, characterized by b ...
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, separate and long exposures through three color filters, complex printing or display procedures, and highly specialized skills, so they were then exceedingly rare. The first practical 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 the sensitivity was later improved. These were "mosaic screen"
additive color Additive color or additive mixing is a property of a color model that predicts the appearance of color Color (American English) or colour (Commonwealth English) is the visual perception, visual perceptual Physical property, property c ...

products, which used a simple layer of black-and-white emulsion in combination with a layer of microscopically small color filter elements. The resulting transparencies or "slides" were very dark because the color filter mosaic layer absorbed most of the light passing through. The last films of this type were discontinued in the 1950s, but Polachrome "instant" slide film, introduced in 1983, temporarily revived the technology. "Color film" in the modern sense of a
subtractive color Subtractive color or subtractive color mixing predicts the spectral power distribution In radiometry, photometry (optics), photometry, and color science, a spectral power distribution (SPD) measurement describes the Power (physics), power per ...
product with a multi-layered emulsion was born with the introduction of
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 f ...
for home movies in 1935 and as lengths of 35 mm film for still cameras in 1936; however, it required a complex development process, with multiple dyeing steps as each color layer was processed separately. 1936 also saw the launch of Agfa Color Neu, the first subtractive three-color reversal film for movie and still camera use to incorporate color dye couplers, which could be processed at the same time by a single color developer. The film had some 278 patents. The incorporation of color couplers formed the basis of subsequent color film design, with the Agfa process initially adopted by Ferrania, Fuji and Konica and lasting until the late 70s/early 1980s in the West and 1990s in Eastern Europe. The process used dye-forming chemicals that terminated with sulfonic acid groups and had to be coated one layer at a time. It was a further innovation by Kodak, using dye-forming chemicals which terminated in 'fatty' tails which permitted multiple layers to coated at the same time in a single pass, reducing production time and cost that later became universally adopted along with the Kodak C-41 process. Despite greater availability of color film after WWII during the next several decades, it remained much more expensive than black-and-white and required much more light, factors which combined the greater cost of processing and printing delayed its widespread adoption. Decreasing cost, increasing sensitivity and standardized processing gradually overcame these impediments. By the 1970s, color film predominated in the consumer market, while the use of black-and-white film was increasingly confined to
photojournalism Photojournalism is journalism that uses images to tell a news story. It usually only refers to still images, but can also refer to video used in broadcast journalism. Photojournalism is distinguished from other close branches of photography (such ...
and
fine art In European academic traditions, fine art is developed primarily for aesthetics Aesthetics, or esthetics (), is a branch of philosophy Philosophy (from , ) is the study of general and fundamental questions, such as those about M ...

photography.

## 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 spectrum, partially color-corrected
achromatic lens An achromatic lens or achromat is a lens (optics), lens that is designed to limit the effects of chromatic aberration, chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into foc ...

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 darkrooms. 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 Filter, filtering or filters may refer to: Science and technology Device * Filter (chemistry), a device which separates solids from fluids (liquids or gases) by adding a medium through which only the fluid can pass ** Filter (aquarium), critical ...
used were different for the different film types.

## Decline

Film remained the dominant form of photography until the early 21st century, when advances in digital photography drew consumers to digital formats. The first consumer electronic camera, the
Sony Mavica Mavica (''Magnetic Video Camera'') is a discontinued brand of Sony cameras which use removable disks as the main recording medium. On August 25th 1981, Sony unveiled a prototype of the Sony Mavica as the world's first electronic still camera. ...

was released in 1981, the first digital camera, the Fuji DS-X released in 1989, coupled with advances in software such as
Adobe Photoshop Adobe Photoshop is a raster graphics editor A screenshot from the GIMP raster graphics editor. A raster graphics editor is a computer program A computer program is a collection of instructions that can be executed by a computer to perfo ...

## Renewed interest in recent years

Despite the fact that digital cameras are by far the most commonly-used photographic tool and that the selection of available photographic films is much smaller than it once was, sales of photographic film have been on a steady upward trend. Kodak (which was under bankruptcy protection from January 2012 to September 2013) and other companies have noticed this upward trend: Dennis Olbrich, President of the Imaging Paper, Photo Chemicals and Film division at Kodak Alaris, has stated that sales of their photographic films have been growing over the past 3 or 4 years. UK-based Ilford have confirmed this trend and conducted extensive research on this subject matter, their research showing that 60% of current film users had only started using film in the past five years and that 30% of current film users were under 35 years old. Annual film sales which were estimated to reach a low point of 5m rolls in 2009 have since doubled to around 10m rolls in 2019. A key challenge for the industry is that production relies on the remaining coating facilities that were built for the peak years of demand, but as demand has grown capacity constraints in some of the other process steps which have been downscaled, such as converting film, have caused production bottlenecks for companies such as Kodak. In 2013
Ferrania FILM Ferrania s.r.l. is a modern photographic film Photographic film is a strip or sheet of transparent film baseA film base is a transparent substrate which acts as a support medium for the photosensitive emulsion An emulsion is a mix ...
, an Italy-based film manufacturer which ceased production of photographic films between the years 2009 and 2010, was acquired by the new Film Ferrania S.R.L taking over a small part of the old company's manufacturing facilities using its former research facility, and re-employed some workers who had been laid off 3 years earlier when the company stopped production of film. In November of the same year, the company started a crowdfunding campaign with the goal of raising $250,000 to buy tooling and machines from the old factory, with the intention of putting some of the films that had been discontinued back into production, the campaign succeeded and in October 2014 was ended with over$320,000 being raised. In February 2017, Film Ferrania unveiled their "P30" 80 ASA, Panchromatic black and white film, in 35mm format. Kodak announced on January 5, 2017, that
Ektachrome Ektachrome is a brand name owned 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 headquarte ...
, one of Kodak's most well known transparency films that had been discontinued between 2012 and 2013, would be reformulated and manufactured once again, in 35 mm still and Super 8 motion picture film formats. Following the success of the release, Kodak expanded Ektachrome's format availability by also releasing the film in 120 and 4x5 formats. Japan-based Fujifilm's instant film "Instax" cameras and paper have also proven to be very successful, and have replaced traditional photographic films as Fujifilm's main film products, while they continue to offer traditional photographic films in various formats and types.

# Image gallery

File:Minox film packages.JPG, 9.5mm film File:Mycro film.jpg, Mycro 17.5mm film File:16mm film.jpg, Kodak Agfa 16 mm film File:120 film.jpg, 120 film File:35mm film.jpg, 35mm film

*
Fogging (photography) Fogging in 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 ...
*
List of photographic equipment makers This list of photographic equipment makers lists companies that manufacture (or license manufacture from other companies) equipment for photography Photography is the art, application, and practice of creating durable images by recording light ...
*
List of photographic films This is a list of currently available 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 hali ...
* Oversampled binary image sensor * Photrio (formerly APUG)

*