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75-478: Snowflakes nucleate around mineral or organic particles in moisture-saturated, subfreezing air masses. They grow by net accretion to the incipient crystals in hexagonal formations. The cohesive forces are primarily electrostatic. In warmer clouds, an aerosol particle or "ice nucleus" must be present in (or in contact with) the droplet to act as a nucleus. The particles that make ice nuclei are very rare compared to nuclei upon which liquid cloud droplets form; however, it

150-456: A microscope from 1885 onward by Wilson Alwyn Bentley found the wide variety of snowflakes we know about today. Ukichiro Nakaya developed a crystal morphology diagram, relating crystal shape to the temperature and moisture conditions under which they formed, which is summarized in the following table: below saturation above saturation Dendrites Hollow prisms Needles Solid plates Dendrites Solid plates Prisms The shape of

225-491: A complex processing procedure. Agfa's similarly structured Agfacolor Neu was introduced in 1936. Unlike Kodachrome, the color couplers in Agfacolor Neu were incorporated into the emulsion layers during manufacture, which greatly simplified the processing. Currently, available color films still employ a multi-layer emulsion and the same principles, most closely resembling Agfa's product. Instant color film , used in

300-451: A degree of image post-processing that is comparatively difficult in film-based photography and permits different communicative potentials and applications. Digital photography dominates the 21st century. More than 99% of photographs taken around the world are through digital cameras, increasingly through smartphones. A large variety of photographic techniques and media are used in the process of capturing images for photography. These include

375-546: A monochrome image from one shot in color. Color photography was explored beginning in the 1840s. Early experiments in color required extremely long exposures (hours or days for camera images) and could not "fix" the photograph to prevent the color from quickly fading when exposed to white light. The first permanent color photograph was taken in 1861 using the three-color-separation principle first published by Scottish physicist James Clerk Maxwell in 1855. The foundation of virtually all practical color processes, Maxwell's idea

450-448: A snowflake is determined primarily by the temperature and humidity at which it is formed. Freezing air down to −3 °C (27 °F) promotes planar crystals (thin and flat). In colder air down to −8 °C (18 °F), the crystals form as hollow columns, prisms or needles. In air as cold as −22 °C (−8 °F), shapes become plate-like again, often with branched or dendritic features. At temperatures below −22 °C (−8 °F),

525-474: A snowflake on the mountain symbol. A stylized snowflake has been part of the emblem of the 1968 Winter Olympics , 1972 Winter Olympics , 1984 Winter Olympics , 1988 Winter Olympics , 1998 Winter Olympics and 2002 Winter Olympics . A six pointed stylized hexagonal snowflake used for the Order of Canada (a national honor system) has come to symbolize Canadians ' northern heritage and diversity. In heraldry,

600-441: A special camera which yielded a unique finished color print only a minute or two after the exposure, was introduced by Polaroid in 1963. Color photography may form images as positive transparencies, which can be used in a slide projector , or as color negatives intended for use in creating positive color enlargements on specially coated paper. The latter is now the most common form of film (non-digital) color photography owing to

675-406: A type of camera obscura in his experiments. The Arab physicist Ibn al-Haytham (Alhazen) (965–1040) also invented a camera obscura as well as the first true pinhole camera . The invention of the camera has been traced back to the work of Ibn al-Haytham. While the effects of a single light passing through a pinhole had been described earlier, Ibn al-Haytham gave the first correct analysis of

750-424: A water droplet has frozen as an ice nucleus, it grows in a supersaturated environment—wherein liquid moisture coexists with ice beyond its equilibrium point at temperatures below freezing. The droplet then grows by deposition of water molecules in the air (vapor) onto the ice crystal surface where they are collected. Because water droplets are so much more numerous than the ice crystals due to their sheer abundance,

825-401: Is a box with a small hole in one side, which allows specific light rays to enter, projecting an inverted image onto a viewing screen or paper. The birth of photography was then concerned with inventing means to capture and keep the image produced by the camera obscura. Albertus Magnus (1193–1280) discovered silver nitrate , and Georg Fabricius (1516–1571) discovered silver chloride , and

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900-542: Is an accepted version of this page Photography is the art , application, and practice of creating images by recording light , either electronically by means of an image sensor , or chemically by means of a light-sensitive material such as photographic film . It is employed in many fields of science, manufacturing (e.g., photolithography ), and business, as well as its more direct uses for art, film and video production , recreational purposes, hobby, and mass communication . A person who captures or takes photographs

975-421: Is an invisible latent image , which is later chemically "developed" into a visible image, either negative or positive , depending on the purpose of the photographic material and the method of processing . A negative image on film is traditionally used to photographically create a positive image on a paper base, known as a print , either by using an enlarger or by contact printing . The word "photography"

1050-443: Is called a photographer . Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure . With an electronic image sensor, this produces an electrical charge at each pixel , which is electronically processed and stored in a digital image file for subsequent display or processing. The result with photographic emulsion

1125-437: Is exploited in silver-based photography . Silver iodide is also used as an antiseptic and in cloud seeding . The structure adopted by silver iodide is temperature dependent: Silver iodide is prepared by reaction of an iodide solution (e.g., potassium iodide ) with a solution of silver ions (e.g., silver nitrate ). A yellowish solid quickly precipitates . The solid is a mixture of the two principal phases. Dissolution of

1200-399: Is kept dark while the object to be photographed is in another room where it is properly illuminated. This was common for reproduction photography of flat copy when large film negatives were used (see Process camera ). As soon as photographic materials became "fast" (sensitive) enough for taking candid or surreptitious pictures, small "detective" cameras were made, some actually disguised as

1275-417: Is not understood what makes them efficient. Clays, desert dust, and biological particles may be effective, although to what extent is unclear. Artificial nuclei include particles of silver iodide and dry ice , and these are used to stimulate precipitation in cloud seeding . Experiments show that "homogeneous" nucleation of cloud droplets only occurs at temperatures lower than −35 °C (−31 °F). Once

1350-459: Is quite popular to make paper snowflakes by folding a piece of paper several times, cutting out a pattern with scissors and then unfolding it. The Book of Isaiah refers to the atonement of sins causing them to appear "white as snow" before God (cf. Isaiah 1:18 ); Snowflakes are also often used as symbols representing winter or cold conditions. For example, snow tires which enhance traction during harsh winter driving conditions are labelled with

1425-419: Is similar to that of ice , allowing it to induce freezing by the process known as heterogeneous nucleation . Approximately 50,000 kg are used for cloud seeding annually, each seeding experiment consuming 10–50 grams. (see also Project Stormfury , Operation Popeye ). Extreme exposure can lead to argyria , characterized by localized discolouration of body tissue. Photography This

1500-399: Is stored electronically, but can be reproduced on a paper. The camera (or ' camera obscura ') is a dark room or chamber from which, as far as possible, all light is excluded except the light that forms the image. It was discovered and used in the 16th century by painters. The subject being photographed, however, must be illuminated. Cameras can range from small to very large, a whole room that

1575-531: Is the earliest known occurrence of the word in public print. It was signed "J.M.", believed to have been Berlin astronomer Johann von Maedler . The astronomer John Herschel is also credited with coining the word, independent of Talbot, in 1839. The inventors Nicéphore Niépce , Talbot, and Louis Daguerre seem not to have known or used the word "photography", but referred to their processes as "Heliography" (Niépce), "Photogenic Drawing"/"Talbotype"/"Calotype" (Talbot), and "Daguerreotype" (Daguerre). Photography

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1650-490: Is the result of combining several technical discoveries, relating to seeing an image and capturing the image. The discovery of the camera obscura ("dark chamber" in Latin ) that provides an image of a scene dates back to ancient China . Greek mathematicians Aristotle and Euclid independently described a camera obscura in the 5th and 4th centuries BCE. In the 6th century CE, Byzantine mathematician Anthemius of Tralles used

1725-613: The Christmas season , especially in Europe and North America. As a Christian celebration, Christmas celebrates the incarnation of Jesus , who according to Christian belief atones for the sins of humanity; so, in European and North American Christmas traditions, snowflakes symbolize purity. Snowflakes are also traditionally associated with the " White Christmas " weather that often occurs during Christmastide. During this period, it

1800-642: The Frauenkirche and other buildings in Munich, then taking another picture of the negative to get a positive , the actual black and white reproduction of a view on the object. The pictures produced were round with a diameter of 4 cm, the method was later named the "Steinheil method". In France, Hippolyte Bayard invented his own process for producing direct positive paper prints and claimed to have invented photography earlier than Daguerre or Talbot. British chemist John Herschel made many contributions to

1875-703: The snowflake is a stylized charge . Three different snowflake symbols are encoded in Unicode : "snowflake" at U+2744 (❄); "tight trifoliate snowflake" at U+2745 (❅); and "heavy chevron snowflake" at U+2746 (❆). In the Tang Dynasty, snowflakes in poetry sometimes served as a symbol of the cosmic energy of the Tao and the Milky Way galaxy . A selection of photographs taken by Wilson Bentley (1865–1931): Comprehensive photographic studies of fresh snowflakes show

1950-403: The 21st century. Hurter and Driffield began pioneering work on the light sensitivity of photographic emulsions in 1876. Their work enabled the first quantitative measure of film speed to be devised. The first flexible photographic roll film was marketed by George Eastman , founder of Kodak in 1885, but this original "film" was actually a coating on a paper base. As part of the processing,

2025-478: The AgI in hydroiodic acid , followed by dilution with water, precipitates β-AgI. Alternatively, dissolution of AgI in a solution of concentrated silver nitrate followed by dilution affords α-AgI. Unless the preparation is conducted in dark conditions, the solid darkens rapidly, the light causing the reduction of ionic silver to metallic. The photosensitivity varies with sample purity. The crystalline structure of β-AgI

2100-694: The French inventor Nicéphore Niépce , but it was destroyed in a later attempt to make prints from it. Niépce was successful again in 1825. In 1826 he made the View from the Window at Le Gras , the earliest surviving photograph from nature (i.e., of the image of a real-world scene, as formed in a camera obscura by a lens ). Because Niépce's camera photographs required an extremely long exposure (at least eight hours and probably several days), he sought to greatly improve his bitumen process or replace it with one that

2175-516: The Nobel Prize in Physics in 1908. Glass plates were the medium for most original camera photography from the late 1850s until the general introduction of flexible plastic films during the 1890s. Although the convenience of the film greatly popularized amateur photography, early films were somewhat more expensive and of markedly lower optical quality than their glass plate equivalents, and until

2250-403: The advantages of being considerably tougher, slightly more transparent, and cheaper. The changeover was not completed for X-ray films until 1933, and although safety film was always used for 16 mm and 8 mm home movies, nitrate film remained standard for theatrical 35 mm motion pictures until it was finally discontinued in 1951. Films remained the dominant form of photography until

2325-474: The atmosphere due to their mass, and may collide and stick together in clusters, or aggregates. These aggregates are usually the type of ice particle that falls to the ground. Guinness World Records lists the world's largest aggregated snowflakes as those of January 1887 at Fort Keogh , Montana , which were claimed to be 15 inches (38 cm) wide—well outside the normally documented range of aggregated flakes of three or four inches in width. Single crystals

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2400-458: The camera and lens to "expose" the light recording material to the required amount of light to form a " latent image " (on plate or film) or RAW file (in digital cameras) which, after appropriate processing, is converted to a usable image. Digital cameras use an electronic image sensor based on light-sensitive electronics such as charge-coupled device (CCD) or complementary metal–oxide–semiconductor (CMOS) technology. The resulting digital image

2475-405: The camera obscura, including the first geometrical and quantitative descriptions of the phenomenon, and was the first to use a screen in a dark room so that an image from one side of a hole in the surface could be projected onto a screen on the other side. He also first understood the relationship between the focal point and the pinhole, and performed early experiments with afterimages , laying

2550-416: The camera, but in 1840 he created the calotype process, which used the chemical development of a latent image to greatly reduce the exposure needed and compete with the daguerreotype. In both its original and calotype forms, Talbot's process, unlike Daguerre's, created a translucent negative which could be used to print multiple positive copies; this is the basis of most modern chemical photography up to

2625-418: The camera; dualphotography; full-spectrum, ultraviolet and infrared media; light field photography; and other imaging techniques. The camera is the image-forming device, and a photographic plate , photographic film or a silicon electronic image sensor is the capture medium. The respective recording medium can be the plate or film itself, or a digital magnetic or electronic memory. Photographers control

2700-451: The changing temperature and humidity within the atmosphere that the snowflake falls through on its way to the ground. Snowflakes that look identical, but may vary at the molecular level, have been grown under controlled conditions. Although snowflakes are never perfectly symmetrical, the growth of a non-aggregated snowflake often approximates six-fold radial symmetry , arising from the hexagonal crystalline structure of ice. At that stage,

2775-406: The conditions and ice nuclei. If a crystal has started forming in a column growth regime, at around −5 °C (23 °F), and then falls into the warmer plate-like regime, then plate or dendritic crystals sprout at the end of the column, producing so called "capped columns". Magono and Lee devised a classification of freshly formed snow crystals that includes 80 distinct shapes. They are listed in

2850-479: The crystals are able to grow to hundreds of micrometers or millimeters in size at the expense of the water droplets. This process is known as the Wegener–Bergeron–Findeisen process . The corresponding depletion of water vapor causes the droplets to evaporate, meaning that the ice crystals grow at the droplets' expense. These large crystals are an efficient source of precipitation, since they fall through

2925-465: The crystals become plate-like or columnar, depending on the degree of saturation. As Nakaya discovered, shape is also a function of whether the prevalent moisture is above or below saturation. Forms below the saturation line trend more towards solid and compact. Crystals formed in supersaturated air trend more towards lacy, delicate and ornate. Many more complex growth patterns also form such as side-planes, bullet-rosettes and also planar types depending on

3000-692: The earliest surviving photographic self-portrait. In Brazil, Hercules Florence had apparently started working out a silver-salt-based paper process in 1832, later naming it Photographie . Meanwhile, a British inventor, William Fox Talbot , had succeeded in making crude but reasonably light-fast silver images on paper as early as 1834 but had kept his work secret. After reading about Daguerre's invention in January 1839, Talbot published his hitherto secret method and set about improving on it. At first, like other pre-daguerreotype processes, Talbot's paper-based photography typically required hours-long exposures in

3075-590: The early 21st century when advances in digital photography drew consumers to digital formats. Although modern photography is dominated by digital users, film continues to be used by enthusiasts and professional photographers. The distinctive "look" of film based photographs compared to digital images is likely due to a combination of factors, including (1) differences in spectral and tonal sensitivity (S-shaped density-to-exposure (H&D curve) with film vs. linear response curve for digital CCD sensors), (2) resolution, and (3) continuity of tone. Originally, all photography

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3150-487: The experiments toward the light-sensitive silver halides , which Niépce had abandoned many years earlier because of his inability to make the images he captured with them light-fast and permanent. Daguerre's efforts culminated in what would later be named the daguerreotype process. The essential elements—a silver-plated surface sensitized by iodine vapor, developed by mercury vapor, and "fixed" with hot saturated salt water—were in place in 1837. The required exposure time

3225-601: The first glass negative in late 1839. In the March 1851 issue of The Chemist , Frederick Scott Archer published his wet plate collodion process . It became the most widely used photographic medium until the gelatin dry plate, introduced in the 1870s, eventually replaced it. There are three subsets to the collodion process; the Ambrotype (a positive image on glass), the Ferrotype or Tintype (a positive image on metal) and

3300-547: The first modern "integral tripack" (or "monopack") color film, was introduced by Kodak in 1935. It captured the three color components in a multi-layer emulsion . One layer was sensitized to record the red-dominated part of the spectrum , another layer recorded only the green part and a third recorded only the blue. Without special film processing , the result would simply be three superimposed black-and-white images, but complementary cyan, magenta, and yellow dye images were created in those layers by adding color couplers during

3375-496: The following main categories (with symbol): They documented each with micrographs. The International Classification for Seasonal Snow on the Ground describes snow crystal classification, once it is deposited on the ground, that include grain shape and grain size. The system also characterizes the snowpack, as the individual crystals metamorphize and coalesce. The snowflake is often a traditional seasonal image or motif used around

3450-445: The foundations for the invention of photography in the 19th century. Leonardo da Vinci mentions natural camerae obscurae that are formed by dark caves on the edge of a sunlit valley. A hole in the cave wall will act as a pinhole camera and project a laterally reversed, upside down image on a piece of paper. Renaissance painters used the camera obscura which, in fact, gives the optical rendering in color that dominates Western Art. It

3525-440: The glass negative, which was used to make positive prints on albumen or salted paper. Many advances in photographic glass plates and printing were made during the rest of the 19th century. In 1891, Gabriel Lippmann introduced a process for making natural-color photographs based on the optical phenomenon of the interference of light waves. His scientifically elegant and important but ultimately impractical invention earned him

3600-436: The ideal six-fold symmetric shape. Very occasionally twelve branched snowflakes are observed; they maintain the six-fold symmetry. Snowflakes form in a wide variety of intricate shapes, leading to the notion that "no two are alike". Although nearly-identical snowflakes have been made in laboratory, they are very unlikely to be found in nature. Initial attempts to find identical snowflakes by photographing thousands of them with

3675-428: The image-bearing layer was stripped from the paper and transferred to a hardened gelatin support. The first transparent plastic roll film followed in 1889. It was made from highly flammable nitrocellulose known as nitrate film. Although cellulose acetate or " safety film " 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

3750-403: The introduction of automated photo printing equipment. After a transition period centered around 1995–2005, color film was relegated to a niche market by inexpensive multi-megapixel digital cameras. Film continues to be the preference of some photographers because of its distinctive "look". In 1981, Sony unveiled the first consumer camera to use a charge-coupled device for imaging, eliminating

3825-436: The inventor of photography. The fiction book Giphantie , published in 1760, by French author Tiphaigne de la Roche , described what can be interpreted as photography. In June 1802, British inventor Thomas Wedgwood made the first known attempt to capture the image in a camera obscura by means of a light-sensitive substance. He used paper or white leather treated with silver nitrate . Although he succeeded in capturing

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3900-404: The late 1910s they were not available in the large formats preferred by most professional photographers, so the new medium did not immediately or completely replace the old. Because of the superior dimensional stability of glass, the use of plates for some scientific applications, such as astrophotography , continued into the 1990s, and in the niche field of laser holography , it has persisted into

3975-741: The need for film: the Sony Mavica . While the Mavica saved images to disk, the images were displayed on television, and the camera was not fully digital. The first digital camera to both record and save images in a digital format was the Fujix DS-1P created by Fujifilm in 1988. In 1991, Kodak unveiled the DCS 100 , the first commercially available digital single-lens reflex camera. Although its high cost precluded uses other than photojournalism and professional photography, commercial digital photography

4050-415: The new field. He invented the cyanotype process, later familiar as the "blueprint". He was the first to use the terms "photography", "negative" and "positive". He had discovered in 1819 that sodium thiosulphate was a solvent of silver halides, and in 1839 he informed Talbot (and, indirectly, Daguerre) that it could be used to "fix" silver-halide-based photographs and make them completely light-fast. He made

4125-560: The overall sensitivity of emulsions steadily reduced the once-prohibitive long exposure times required for color, bringing it ever closer to commercial viability. Autochrome , the first commercially successful color process, was introduced by the Lumière brothers in 1907. Autochrome plates incorporated a mosaic color filter layer made of dyed grains of potato starch , which allowed the three color components to be recorded as adjacent microscopic image fragments. After an Autochrome plate

4200-545: The present day, as daguerreotypes could only be replicated by rephotographing them with a camera. Talbot's famous tiny paper negative of the Oriel window in Lacock Abbey , one of a number of camera photographs he made in the summer of 1835, may be the oldest camera negative in existence. In March 1837, Steinheil, along with Franz von Kobell , used silver chloride and a cardboard camera to make pictures in negative of

4275-1087: The process. The cyanotype process, for example, produces an image composed of blue tones. The albumen print process, publicly revealed in 1847, produces brownish tones. Many photographers continue to produce some monochrome images, sometimes because of the established archival permanence of well-processed silver-halide-based materials. Some full-color digital images are processed using a variety of techniques to create black-and-white results, and some manufacturers produce digital cameras that exclusively shoot monochrome. Monochrome printing or electronic display can be used to salvage certain photographs taken in color which are unsatisfactory in their original form; sometimes when presented as black-and-white or single-color-toned images they are found to be more effective. Although color photography has long predominated, monochrome images are still produced, mostly for artistic reasons. Almost all digital cameras have an option to shoot in monochrome, and almost all image editing software can combine or selectively discard RGB color channels to produce

4350-514: The scene, appeared as brightly colored ghosts in the resulting projected or printed images. Implementation of color photography was hindered by the limited sensitivity of early photographic materials, which were mostly sensitive to blue, only slightly sensitive to green, and virtually insensitive to red. The discovery of dye sensitization by photochemist Hermann Vogel in 1873 suddenly made it possible to add sensitivity to green, yellow and even red. Improved color sensitizers and ongoing improvements in

4425-410: The shadows of objects placed on the surface in direct sunlight, and even made shadow copies of paintings on glass, it was reported in 1802 that "the images formed by means of a camera obscura have been found too faint to produce, in any moderate time, an effect upon the nitrate of silver." The shadow images eventually darkened all over. The first permanent photoetching was an image produced in 1822 by

4500-464: The simple symmetry represented in Bentley's photographs to be rare. Silver iodide Silver iodide is an inorganic compound with the formula Ag I . The compound is a bright yellow solid, but samples almost always contain impurities of metallic silver that give a grey colouration. The silver contamination arises because some samples of AgI can be highly photosensitive . This property

4575-414: The size of a dime (17.91 mm in diameter) have been observed. Snowflakes encapsulated in rime form balls known as graupel . Although ice by itself is clear, snow usually appears white in color due to diffuse reflection of the whole spectrum of light by the scattering of light by the small crystal facets of the snowflakes of which it is comprised. The shape of the snowflake is determined broadly by

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4650-417: The snowflake has the shape of a minute hexagon. The six "arms" of the snowflake, or dendrites, then grow independently from each of the corners of the hexagon, while either side of each arm grows independently. The microenvironment in which the snowflake grows changes dynamically as the snowflake falls through the cloud and tiny changes in temperature and humidity affect the way in which water molecules attach to

4725-466: The snowflake. Since the micro-environment (and its changes) are very nearly identical around the snowflake, each arm tends to grow in nearly the same way. However, being in the same micro-environment does not guarantee that each arm grows the same; indeed, for some crystal forms it does not because the underlying crystal growth mechanism also affects how fast each surface region of a crystal grows. Empirical studies suggest less than 0.1% of snowflakes exhibit

4800-536: The techniques described in Ibn al-Haytham 's Book of Optics are capable of producing primitive photographs using medieval materials. Daniele Barbaro described a diaphragm in 1566. Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694. Around 1717, Johann Heinrich Schulze used a light-sensitive slurry to capture images of cut-out letters on a bottle and on that basis many German sources and some international ones credit Schulze as

4875-478: The temperature and humidity at which it is formed. Rarely, at a temperature of around −2 °C (28 °F), snowflakes can form in threefold symmetry — triangular snowflakes. Most snow particles are irregular in form, despite their common depiction as symmetrical. It is unlikely that any two snowflakes are alike due to the estimated 10 (10 quintillion) water molecules which make up a typical snowflake, which grow at different rates and in different patterns depending on

4950-518: The three images made in their complementary colors , a subtractive method of color reproduction pioneered by Louis Ducos du Hauron in the late 1860s. Russian photographer Sergei Mikhailovich Prokudin-Gorskii made extensive use of this color separation technique, employing a special camera which successively exposed the three color-filtered images on different parts of an oblong plate . Because his exposures were not simultaneous, unsteady subjects exhibited color "fringes" or, if rapidly moving through

5025-537: The word, photographie , in private notes which a Brazilian historian believes were written in 1834. This claim is widely reported but is not yet largely recognized internationally. The first use of the word by Florence became widely known after the research of Boris Kossoy in 1980. The German newspaper Vossische Zeitung of 25 February 1839 contained an article entitled Photographie , discussing several priority claims – especially Henry Fox Talbot 's – regarding Daguerre's claim of invention. The article

5100-486: Was monochrome , or black-and-white . Even after color film was readily available, black-and-white photography continued to dominate for decades, due to its lower cost, chemical stability, and its "classic" photographic look. The tones and contrast between light and dark areas define black-and-white photography. Monochromatic pictures are not necessarily composed of pure blacks, whites, and intermediate shades of gray but can involve shades of one particular hue depending on

5175-407: Was reversal processed to produce a positive transparency , the starch grains served to illuminate each fragment with the correct color and the tiny colored points blended together in the eye, synthesizing the color of the subject by the additive method . Autochrome plates were one of several varieties of additive color screen plates and films marketed between the 1890s and the 1950s. Kodachrome ,

5250-409: Was born. Digital imaging uses an electronic image sensor to record the image as a set of electronic data rather than as chemical changes on film. An important difference between digital and chemical photography is that chemical photography resists photo manipulation because it involves film and photographic paper , while digital imaging is a highly manipulative medium. This difference allows for

5325-516: Was created from the Greek roots φωτός ( phōtós ), genitive of φῶς ( phōs ), "light" and γραφή ( graphé ) "representation by means of lines" or "drawing", together meaning "drawing with light". Several people may have coined the same new term from these roots independently. Hércules Florence , a French painter and inventor living in Campinas, Brazil , used the French form of

5400-405: Was measured in minutes instead of hours. Daguerre took the earliest confirmed photograph of a person in 1838 while capturing a view of a Paris street: unlike the other pedestrian and horse-drawn traffic on the busy boulevard, which appears deserted, one man having his boots polished stood sufficiently still throughout the several-minutes-long exposure to be visible. The existence of Daguerre's process

5475-399: Was more practical. In partnership with Louis Daguerre , he worked out post-exposure processing methods that produced visually superior results and replaced the bitumen with a more light-sensitive resin, but hours of exposure in the camera were still required. With an eye to eventual commercial exploitation, the partners opted for total secrecy. Niépce died in 1833 and Daguerre then redirected

5550-403: Was publicly announced, without details, on 7 January 1839. The news created an international sensation. France soon agreed to pay Daguerre a pension in exchange for the right to present his invention to the world as the gift of France, which occurred when complete working instructions were unveiled on 19 August 1839. In that same year, American photographer Robert Cornelius is credited with taking

5625-438: Was to take three separate black-and-white photographs through red, green and blue filters . This provides the photographer with the three basic channels required to recreate a color image. Transparent prints of the images could be projected through similar color filters and superimposed on the projection screen, an additive method of color reproduction. A color print on paper could be produced by superimposing carbon prints of

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