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Platinum Prints
Platinum prints, also called ''platinotypes'', are photographic prints made by a monochrome printing process involving platinum. Platinum tones range from warm black, to reddish brown, to expanded mid-tone grays that are unobtainable in silver prints. Unlike the silver print process, platinum lies on the paper surface, while silver lies in a gelatin or albumen emulsion that coats the paper. As a result, since no gelatin emulsion is used, the final platinum image is absolutely matte with a deposit of platinum (and/or palladium, its sister element which is also used in most platinum photographs) absorbed slightly into the paper. Platinum prints are the most durable of all photographic processes. The platinum group metals are very stable against chemical reactions that might degrade the print—even more stable than gold. It is estimated that a platinum image, properly made, can last thousands of years. Some of the desirable characteristics of a platinum print include: * The r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coming Home From The Marshes, Peter Henry Emerson, 1886
Come may refer to: *Comè, a city and commune in Benin *Come (Tenos), an ancient town on Tenos island, Greece Music *Come (American band), an American indie rock band formed in 1990 *Come (UK band), a British noise project founded in 1979 **Come Organisation, its record label * ''Come'' (album), a 1994 album by Prince * "Come", a song by Fleetwood Mac from '' Say You Will'' * "Come" (Jain song), 2015 * "Come" (Jenny Berggren song), 2015 Other *COMe, COM Express, a single-board computer type *A possible outcome which may be bet on in craps, whence the general gambling expression See also *Cum (other) Cum may refer to: * a Latin preposition meaning "with" * Antonio José de Sucre Airport, Venezuela, IATA airport code CUM * Culham railway station, Oxfordshire, England, CUM, station code CUM * "Cum", a song by Mykki Blanco from the 2012 EP ... * Saint-Côme (other) {{Disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Tetrachloropalladate
Sodium tetrachloropalladate is an inorganic compound with the chemical formula Na2PdCl4. This salt, and the analogous alkali metal salts of the form M2PdCl4, may be prepared simply by reacting palladium(II) chloride with the appropriate alkali metal chloride in aqueous solution. Palladium(II) chloride is insoluble in water, whereas the product dissolves: : PdCl2 + 2 MCl → M2PdCl4 The compound crystallizes from water as trihydrate (Na2PdCl4·3H2O, reddish-brown powder with molar mass 348.22), which is the commercially available form. This compound may further react with phosphines to give phosphine complexes of palladium. An alternative method of preparing such phosphine complexes is to break up the coordination polymer of palladium(II) chloride into reactive, monomeric acetonitrile or benzonitrile complexes, followed by reaction with phosphine Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnicto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt Print
The salt print was the dominant paper-based photographic process for producing positive prints (from negatives) from 1839 until approximately 1860. The salted paper technique was created in the mid-1830s by English scientist and inventor Henry Fox Talbot. He made what he called "sensitive paper" for "photogenic drawing" by wetting a sheet of writing paper with a weak solution of ordinary table salt ( sodium chloride), blotting and drying it, then brushing one side with a strong solution of silver nitrate. This produced a tenacious coating of silver chloride an especially light-sensitive chemical condition. The paper darkened where it was exposed to light. When the darkening was judged to be sufficient, the exposure was ended and the result was stabilized by applying a ''strong'' solution of salt, which altered the chemical balance and made the paper only slightly sensitive to additional exposure. In 1839, washing with a solution of sodium thiosulfate ("hypo") was found to be th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive (photography)
Positive has multiple meanings in the world of photography. The two main definitions of positive photography include positive space and positive film. Positive space Positive space is the idea that any part of a photo that includes the subject, stands out from the rest of the photo. It is key component in most photographs that helps convey emotions towards an audience. The technique can illustrate emotions ranging from crowdedness, to power, to chaos, or even to movement in a photo. Positive photos often busy and active so that most of the focus is drawn towards the subject. It is important to note that positive space in photography is usually balanced with negative space to make an appealing composition. For example, if a photo is over-crowded and it is hard to distinguish what is and is not the subject of the photo (meaning there is a lack of definition or negative space, or there's too much negative space), then the photo may not be compositionally well thought out or perhaps fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative (photography)
In photography, a negative is an image, usually on a strip or sheet of transparent plastic film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest. This reversed order occurs because the extremely light-sensitive chemicals a camera film must use to capture an image quickly enough for ordinary picture-taking are darkened, rather than bleached, by exposure to light and subsequent photographic processing. In the case of color negatives, the colors are also reversed into their respective complementary colors. Typical color negatives have an overall dull orange tint due to an automatic color-masking feature that ultimately results in improved color reproduction. Negatives are normally used to make positive prints on photographic paper by projecting the negative onto the paper with a photographic enlarger or making a contact print. The paper is also darkened in proportion to its exposure to light, so a second reversal r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Printing
Photographic printing is the process of producing a final image on paper for viewing, using chemically sensitized paper. The paper is exposed to a photographic negative, a positive transparency (or ''slide''), or a digital image file projected using an enlarger or digital exposure unit such as a LightJet or Minilab printer. Alternatively, the negative or transparency may be placed atop the paper and directly exposed, creating a contact print. Digital photographs are commonly printed on plain paper, for example by a color printer, but this is not considered "photographic printing". Following exposure, the paper is processed to reveal and make permanent the latent image. Printing on black-and-white paper The process consists of four major steps, performed in a photographic darkroom or within an automated photo printing machine. These steps are: *Exposure of the image onto the sensitized paper using a contact printer or enlarger; * Processing of the latent image using t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Hunt (scientist)
Robert Hunt (6 September 1807 – 17 October 1887) was a British mineralogist, as well as an antiquarian, an amateur poet, and an early pioneer of photography. He was born at Devonport, Plymouth and died in London on 17 October 1887. Life and work Early life Hunt's father, a naval officer, drowned while Robert was a youth. Robert began to study in London for the medical profession, but ill-health caused him to return to settle in Cornwall. In 1829, he published ''The Mount’s Bay; a descriptive poem ... and other pieces'' but received little critical or financial success.Alan Pearson, 'Hunt, Robert (1807–1887)’, Oxford Dictionary of National Biography, Oxford University Press, 200 Retrieved 16 Jan 2011/ref> In 1840, Hunt became secretary to the Royal Cornwall Polytechnic Society at Falmouth. Here he met Robert Were Fox, and carried on some physical and chemical investigations with him. Career He was appointed Professor of Mechanical Science, Government School o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical work. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus – the seventh planet, discovered by his father Sir William Herschel. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays. His ''Preliminary Discourse'' (1831), which advocated an inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science. Early life and work on astronomy Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and astronomer William Herschel. He was the nephew of astronomer Caroline Herschel. He studied shortly at Eton Colle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Wolfgang Döbereiner
Johann Wolfgang Döbereiner (13 December 1780 – 24 March 1849) was a German chemist who is best known for work that foreshadowed the periodic law for the chemical elements, and for inventing the first lighter, which was known as the Döbereiner's lamp. He became a professor of chemistry and pharmacy at the University of Jena. Life and work As a coachman's son, Döbereiner had little opportunity for formal schooling. Thus, he was apprenticed to an apothecary, and began to read widely and to attend science lectures. He eventually became a professor at the University of Jena in 1810 and also studied chemistry at Strasbourg. In work published in 1829, Döbereiner reported trends in certain properties of selected groups of elements. For example, the average of the atomic masses of lithium and potassium was close to the atomic mass of sodium. A similar pattern was found with calcium, strontium, and barium; with sulfur, selenium, tellurium; and with chlorine, bromine, and iodine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferdinand Gehlen
Ferdinand is a Germanic name composed of the elements "protection", "peace" (PIE "to love, to make peace") or alternatively "journey, travel", Proto-Germanic , abstract noun from root "to fare, travel" (PIE , "to lead, pass over"), and "courage" or "ready, prepared" related to Old High German "to risk, venture." The name was adopted in Romance languages from its use in the Visigothic Kingdom. It is reconstructed as either Gothic or . It became popular in German-speaking Europe only from the 16th century, with Habsburg rule over Spain. Variants of the name include , , , and in Spanish, in Catalan, and and in Portuguese. The French forms are , '' Fernand'', and , and it is '' Ferdinando'' and in Italian. In Hungarian both and are used equally. The Dutch forms are and '' Ferry''. There are numerous short forms in many languages, such as the Finnish . There is a feminine Spanish, Portuguese and Italian form, . Royalty Aragón/León/Castile/Spain *Ferdi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Film Grain
Film grain or granularity is the random optical texture of processed photographic film due to the presence of small particles of a metallic silver, or dye clouds, developed from silver halide that have received enough photons. While film grain is a function of such particles (or dye clouds) it is not the same thing as such. It is an optical effect, the magnitude of which (amount of grain) depends on both the film stock and the definition at which it is observed. It can be objectionably noticeable in an over-enlarged film photograph. RMS granularity Granularity, or RMS granularity, is a numerical quantification of density non-uniformity, equal to the root-mean-square (rms) fluctuations in optical density, measured with a microdensitometer with a 0.048 mm (48-micrometre) diameter circular aperture, on a film area that has been exposed and normally developed to a mean density of 1.0 D (that is, it transmits 10% of light incident on it). Granularity is sometimes quoted as "dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
