- This article is mainly concerned with still photography film. Photography (fә'tɒgrәfi or fә'tɑːgrәfi (from Greek φωτο and γραφία is the process and Art of recording pictures by means of capturing For motion picture film, please see film stock. This focuses on Motion picture film For Still photography film see Photographic film.
Photographic film is a sheet of plastic (polyester, nitrocellulose or cellulose acetate) coated with an emulsion containing light-sensitive silver halide salts (bonded by gelatin) with variable crystal sizes that determine the sensitivity, contrast and resolution of the film. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products Polyester is a category of Polymers which contain the Ester Functional group in their main chain Nitrocellulose (also cellulose nitrate, flash paper) is a highly flammable compound formed by Nitrating Cellulose through exposure to Cellulose acetate, first prepared in 1865 is the Acetate Ester of Cellulose. An emulsion ( IPA: /ɪˈmʌlʃən/ is a mixture of two Immiscible (unblendable liquids A silver halide is one of the compounds formed between Silver and one of the Halogens &mdash Silver bromide (AgBr chloride Gelatin (also gelatine, from French gélatine) is a translucent colourless brittle nearly tasteless solid substance, extracted from the Image resolution describes the detail an Image holds The term applies equally to Digital images film images and other types of images When the emulsion is sufficiently exposed to light (or other forms of electromagnetic radiation such as X-rays), it forms a latent (invisible) image. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. A latent image on Photographic film is an invisible image produced by the exposure of the film to Light. Chemical processes can then be applied to the film to create a visible image, in a process called film developing. Photographic processing is the Industrial process by which conventional Photographic film is treated after Photographic exposure in order to produce the
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 block light and appear as the black part of the film negative.
Color film uses at least three layers. Dyes, which adsorb to the surface of the silver salts, make the crystals sensitive to different colors. Adsorption is a process that occurs when a gas or liquid Solute accumulates on the surface of a solid or a liquid (adsorbent forming a film of molecules or atoms (the 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, have as many as 12 emulsion layers, with upwards of 20 different chemicals in each layer. For other uses of the "Kodacolor" brand see Kodacolor.
Because photographic film is widespread in the production of motion pictures, or movies, these are also known as films.
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Film basics
There are two primary types of photographic film:
- Print film, when developed, turns into a negative with the colors (or black and white values, in black and white film) inverted. In photography a negative may refer to three different things although they are all related This type of film must be "printed" — either projected through a lens or placed in contact — to photographic paper in order to be viewed as intended. Photographic paper is paper coated with Light -sensitive chemicals used for making Photographic prints Photographic paper differs from photo papers Print films are available in both black-and-white and color. Black-and-white is a number of Monochrome forms in Visual arts. Color print film is the most common type of Photographic film in consumer use
- Color reversal film after development is called a transparency and can be viewed directly using a loupe or projector. In Photography, a reversal film is a still positive image created on a transparent base using photochemical means In Photography, a reversal film is a still positive image created on a transparent base using photochemical means A loupe (pronounced loop) is a type of Magnification device used to see things one is looking at more closely A slide projector is an opto-mechanical device to view photographic slides. 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 scans or color separations for mass-market printing. A film scanner is a device made for Scanning Photographic film directly into a computer without the use of any intermediate printmaking Printing is a process for reproducing text and image typically with ink on Paper using a printing press 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—one of the reasons reversal films are popular among professional photographers is the fact that they are generally superior to print films with regards to color reproduction. In Photography, a reversal film is a still positive image created on a transparent base using photochemical means (Conventional black and white negative stock can be reversal-processed, to give "black & white slides", and kits are available to enable this to be done by home-processors. As indicated by Grant Haist's published book Modern Photographic Processing, B&W transparencies can be produced from most all B&W films. )
In order to produce a usable image, the film needs to be exposed properly. In Photography, exposure is the total amount of Light allowed to fall on the photographic medium ( Photographic film or Image sensor) during the 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 of the optical transmission coefficient of the developed film. In Optics, density is a unitless measure of the Transmittance of an optical element for a given length at a given Wavelength λ: In Mathematics, the logarithm of a number to a given base is the power or Exponent to which the base must be raised in order to produce See also Reflection coefficient The transmission coefficient is used in physics and electrical engineering when Wave propagation in a medium containing 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 of random grain activation by photons. Statistics is a mathematical science pertaining to the collection analysis interpretation or explanation and presentation of Data. 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. In Mathematics, a multiplicative inverse for a number x, denoted by 1&frasl x or x &minus1 is a number which This is due to the statistics of grain activation: as the film becomes progressively more exposed, each incident photon is less likely to impact a still-unexposed grain, yielding the logarithmic behavior. In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena A simple, idealized statistical model yields the equation density = 1 - ( 1 - k ) ^ light, 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 lightbulb, 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. The Zone System is a photographic technique for determining optimal film exposure and development, formulated by Ansel Adams and Most automatic cameras instead try to achieve a particular average density. A camera is a device used to capture images either as still Photographs or as sequences of moving images ( Movies or Videos.
Film speed
Film speed describes a film's threshold sensitivity to light. Film speed is the measure of a photographic film's sensitivity to Light. The international standard for rating film speed is the ISO scale which combines both the ASA speed and the DIN speed in the format ASA/DIN. Deutsches Institut für Normung eV ( DIN; in English, the German Institute for Standardization) is the German national organization for Using ISO convention film with an ASA speed of 400 would be labeled 400/27°. A fourth naming standard is GOST, developed by the Russian standards authority. GOST refers to a set of technical standards maintained by the Euro-Asian Council for Standardization Metrology and Certification (EASC a regional Standards organization See the film speed article for a table of conversions between ASA, DIN, and GOST film speeds. Film speed is the measure of a photographic film's sensitivity to Light.
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, are not ISO rated and therefore careful examination of the film's properties must be made by the photographer before exposure and development. Technical Pan was a Panchromatic Black and white film produced by Kodak with unique characteristics that have not been replicated ISO 25 film is very "slow", as it requires much more exposure to produce a usable image than "fast" ISO 800 film. In Photography, exposure is the total amount of Light allowed to fall on the photographic medium ( Photographic film or Image sensor) during the 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 films is that it usually has finer grain and better color rendition than fast film. Professional photography with static subjects such as portraits or landscapes usually seek these qualities, and therefore require a tripod 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 to behave like a film with a higher ISO. Push processing is a term from Photography, referring to a development technique that increases the speed of the film being processed 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
- See also: Nitrocellulose#Nitrate film
Hurter & Driffield began pioneering work on the light sensitivity of film in 1876 onwards. Nitrocellulose (also cellulose nitrate, flash paper) is a highly flammable compound formed by Nitrating Cellulose through exposure to Sensitometry is the scientific study of light-sensitive materials especially Photographic film. Their work enabled the first quantitative measure of film speed to be devised.
Early photography in the form of daguerreotypes did not use film at all. The daguerreotype (original French daguerréotype) is an early type of Photograph, developed by Louis Daguerre, in which the image is exposed directly Eastman Kodak developed the first flexible photographic film in 1885. Eastman Kodak Company ( is an American multinational Public company which produces imaging and photographic materials and equipment Year 1885 ( MDCCCLXXXV) was a Common year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Common This original "film" was coated on paper. The first transparent plastic film was produced in 1889. Before this, glass photographic plates were used, which were far more expensive and cumbersome, albeit also of better quality. Photographic plates preceded Photographic film as a mean of photography The first photographic film was made from highly flammable nitrocellulose with camphor as a plasticizer (celluloid). Nitrocellulose (also cellulose nitrate, flash paper) is a highly flammable compound formed by Nitrating Cellulose through exposure to } Camphor is a waxy white or transparent solid with a strong aromatic odor Plasticizers are additives that increase the Plasticity or Fluidity of the material to which they are added these include plastics cement concrete wallboard and Celluloid is the name of a class of compounds created from Nitrocellulose and Camphor, plus dyes and other agents Beginning in the 1920s, nitrate film was replaced with cellulose acetate or "safety film". The 1920s is sometimes referred to as the " Jazz Age " or the " Roaring Twenties " when speaking about the United States and Canada Cellulose acetate, first prepared in 1865 is the Acetate Ester of Cellulose. Because of the highly flammable nature of cellulose Nitrate film, by the beginning of the 20th century manufacturers had begun to introduce Cellulose acetate as a safe alternative This changeover was not completed until 1933 for X-ray films (where its flammability hazard was most acute) and for motion picture film until 1951. Year 1933 ( MCMXXXIII) was a Common year starting on Sunday (link will display full calendar of the Gregorian calendar. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Year 1951 ( MCMLI) was a Common year starting on Monday. Events of 1951 January
Spectral sensitivity
The first films were sensitive to blue light only. Orthochromatic film sensitive to the spectral range from green to blue was introduced in 1879 and was dominant until the mid-1920s, when panchromatic film sensitive to the entire visual spectrum, became standard. Orthochromatic refers to any spectrum of light that is devoid of red light Panchromatic film is a type of Black-and-white Photographic film that is sensitive to all Wavelengths of Visible light. All of these films were used to produce black and white images, regardless of spectral sensitivity. Black-and-white is a number of Monochrome forms in Visual arts.
Experiments with color photography were first made in 1861, but generally usable emulsions only became available in the 1930s. "Color film" redirects here For the motion picture equivalent see Color motion picture film. After World War II much progress was made, and color became used for the overwhelming majority of photographs. World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including
Effect on lens and equipment design
Photographic lenses and equipment are designed around the film to be used. The earliest lenses needed to focus blue light only. The introduction of orthochromatic film required the spectrum from green to blue to be brought to the same focus. A red window could be used to view frame numbers of rollfilm; any red light which leaked beyond the film backing would not fog the film; and red lighting could be used in darkrooms. A darkroom is a workspace usually a separate area in a building or a vehicle made dark to allow Photographers to use Light -sensitive materials to develop film With the introduction of panchromatic film the whole visual spectrum needed to be brought to the same 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 with the introduction of color film. More highly corrected lenses for newer emulsions could be used with older emulsion types, but the converse was not true.
The filters used were different for the different film types. In Photography, a filter is a Camera accessory consisting of an optical filter that can be inserted in the optical path
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.
While color processing is more complex and temperature-sensitive than for monochromatic film, the great popularity of color and almost disappearance of monochrome prompted the design of monochromatic film which is processed in exactly the same way as a standard color film.
Special films
Instant photography, as popularised by Polaroid, uses a special type of camera and film that automates and integrates development, without the need of further equipment or chemicals. Polaroid Corporation was founded in 1937 by Edwin H Land. It is most famous for its Instant film Cameras which reached the market in 1948 and 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 is a Photographic film that is designed to be used in an Instant camera (and with accessory hardware with many professional film cameras
Films can be made to record non-visible ultraviolet (UV) and infrared (IR) radiation. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies These films generally require special equipment; for example, most photographic lenses are made of glass and will therefore filter out most ultraviolet light. A photographic lens (also known as objective lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many Instead, expensive lenses made of quartz must be used. Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Infrared films may be shot in standard cameras using an infrared band- or long-pass filter, although the infrared focal point must be compensated for. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of An optical filter is a device which selectively transmits light having certain properties (often a particular range of Wavelengths that is range of Colours
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, bracketing is the general technique of taking several shots of the same subject using different or the same camera settings 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 father away from the camera than visible light, and UV slightly closer; this must be compensated for when focussing. Apochromatic lenses are sometimes recommended due to their improved focusing across the spectrum.
Film optimized for sensing X-ray radiation is commonly used for medical imaging 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. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Medical imaging refers to the techniques and processes used to create Images of the human body (or parts thereof for clinical purposes ( Medical procedures seeking to
Film optimized for sensing X-rays and for gamma rays is sometimes used for radiation dosimetry and personal monitoring. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions Radiation dosimetry is the calculation of the Absorbed dose in matter and tissue resulting from the exposure to Ionizing radiation.
Film has a number of disadvantages as a scientific detector: it is difficult to calibrate for photometry, 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 CCDs that might have pixels of about 10 micrometres and a dynamic range of 3-4 orders of magnitude. A charge-coupled device ( CCD) is an analog Shift register, that enables the transportation of analog signals (electric charges through successive stages (capacitors
Special films are used for the long exposures required by astrophotography. Astrophotography is a specialized type of Photography that entails making photographs of astronomical objects in the sky such as the Moon, Sun, Planets
Common sizes of film
- See also: Film format
- 135 (popularly known as "35 mm")
- APS (Advanced Photo System)
- 110
- 126
- 127
- 120/220 (for use in medium format photography)
- Sheet film (for use in large format photography)
- Disc film Obsolete format used in disc system cameras
- Motion picture films: 8 mm, 16 mm, 35 mm and 70 mm
Companies that manufacture photographic film
- *:discontinued,**:bankruptcy
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Film manufacturers commonly make film that is branded by other companies. ( established in 1876 is a Japanese printing company It is involved in a wide variety of printing processes ranging from magazines through to Shadow masks for the production of Efke is the brand name of Photographic films papers, and chemicals manufactured by Fotokemika d Ferrania SpA is a manufacturer of photographic materials located in Ferrania Italy. is a Japanese company known for its Photographic film and Cameras Fujifilm is the world’s largest photographic and imaging company. Ilford Photo is a maker of Photographic films paper, and chemicals Imation is a US based multi-national Corporation that designs manufactures sources or markets a wide range of recordable data storage media and consumer electronics products 3M Company ( formerly Minnesota Mining and Manufacturing Company until 2002 is an American multinational conglomerate corporation with a worldwide Eastman Kodak Company ( is an American multinational Public company which produces imaging and photographic materials and equipment is a Japanese manufacturer of office equipment Medical imaging, Graphic imaging, Optical devices and Measuring instruments The company China Lucky Film corporation is the largest photosensitive materials and magnetic recording media manufacturer in China. Maco is a Germany based supplier of Photographic films including old 127 size film The, Mitsubishi Group of Companies, or Mitsubishi Companies is a Japanese conglomerate consisting of a range of autonomous businesses which share the Mitsubishi ORWO was a manufacturer of Photographic film and Magnetic tape. Polaroid Corporation was founded in 1937 by Edwin H Land. It is most famous for its Instant film Cameras which reached the market in 1948 and Svema (Свема is a registered Trade mark and former name ("NPO "Svema" of the Shostka Chemical Plant located in Shostka, Sumy Oblast Modern films have bar codes 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, read the bar code printed on the cassette. An original equipment manufacturer, or OEM is typically a company that uses a component made by a second company in its own product or sells the product of the second company 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
Notable films
- Kodak Kodachrome is one of the oldest slide films still being produced and is known for its long archive stability. Kodachrome is the trademarked name of a brand of color reversal film sold by Eastman Kodak. In Photography, a reversal film is a still positive image created on a transparent base using photochemical means
- Fuji Velvia, also a slide film, is known for its high contrast and hyper-saturated colors. Velvia is a brand of daylight-balanced color reversal film produced by the Japanese company Fujifilm. It is popular with landscape and nature photographers.
- Both Kodak T-max p3200 and Ilford Delta 3200 are B&W films with very wide exposure latitude. Delta is a tabular-grain Black-and-white film from Ilford Photo. They are rated at roughly ISO 1000, but can be pushed to ISO 3200 or higher. Push processing is a term from Photography, referring to a development technique that increases the speed of the film being processed Rated speeds of as high as ISO 25,000 have been obtained.
- Kodak Technical Pan, which has now been discontinued, is a widely acclaimed slow black and white film. Technical Pan was a Panchromatic Black and white film produced by Kodak with unique characteristics that have not been replicated With a speed of ISO 25, it gave clear, incredibly fine-grained results. It has now become somewhat of a commodity item among photographers as it is very limited, and very little if any stock remains at photographic suppliers.
See also
- Camera
- Film base
- Film stock for cinematography
- List of film formats
- List of photographic equipment makers
- List of photographic films
- Sensitometry
- APUG
- Timeline of photography technology
References
- Modern Photographic Processing: Grant Haist
- APUG (traditional photography 'analog' forums)
- dr5. A camera is a device used to capture images either as still Photographs or as sequences of moving images ( Movies or Videos. A film base is a transparent substrate which acts as a support medium for the Photosensitive Emulsion that lies atop it This focuses on Motion picture film For Still photography film see Photographic film. See also Filmmaking Cinematography (from Greek: kinesis κινησις (movement and grapho γραφω (to record is the discipline This list of Film formats catalogues formats developed for shooting or viewing Motion pictures, ranging from the Chronophotographe format from 1888 to mid-20th century This list of photographic equipment makers lists companies that manufacture (or license manufacture from other companies equipment for Photography. Fujifilm Velvia 50 Type Color Reversal Speed ISO 50/18° Available formats 35 mm 120 220 4x5" Sensitometry is the scientific study of light-sensitive materials especially Photographic film. APUG is the A nalog P hotography U sers G roupan International group of photographers dedicated to film based analog Photography Timeline of Photography Technology 1826 - Nicéphore Niépce takes the first permanent Photograph, a landscape com (B&W reversal)
- British Journal of Photography
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