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Latent Image
A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer. In more physical terms, a latent image is a small cluster of metallic silver atoms formed in or on a silver halide crystal due to reduction of interstitial silver ions by photoelectrons (a photolytic silver cluster). If intense exposure continues, such photolytic silver clusters grow to visible sizes. This is called ''printing out'' the image. On the other hand, the formation of a visible image by the action of photographic developer is called ''developing out'' the image. The size of a silver cluster in the latent ima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light
Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequency, frequencies of 750–420 terahertz (unit), terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively ''optical radiation''. In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity (physics), intensity, propagation direction, frequency or wavelength spectrum, and polarization (waves), polarization. Its speed of light, speed in vacuum, , is one of the fundamental physi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latent Image
A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer. In more physical terms, a latent image is a small cluster of metallic silver atoms formed in or on a silver halide crystal due to reduction of interstitial silver ions by photoelectrons (a photolytic silver cluster). If intense exposure continues, such photolytic silver clusters grow to visible sizes. This is called ''printing out'' the image. On the other hand, the formation of a visible image by the action of photographic developer is called ''developing out'' the image. The size of a silver cluster in the latent ima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nils Strindberg
Nils Strindberg (4 September 1872 – October 1897) was a Swedish photographer and scientist. He was one of the three members of S. A. Andrée's ill-fated Arctic balloon expedition of 1897. Biography Nils Strindberg was born in Stockholm, Sweden. He was the son of wholesaler Johan Oscar Strindberg and Aurora Helena Rosalie Lundgren. His younger brother, Tore Strindberg (1882-1968), was a noted sculptor. His father's cousin was playwright and novelist August Strindberg (1849–1912). Strindberg graduated from Norra Real in Stockholm during 1890. He received his Bachelor of Arts (''fil.kand.'') at Uppsala University in 1893. In 1895, received a post as lector at the Stockholm University. In the spring of 1896 he traveled to Paris to study gas balloon flight. Strindberg was invited to the Arctic balloon expedition of 1897 to create a photographic aerial record of the arctic. Before perishing on Kvitøya (White Island) with Andrée and Knut Frænkel, Strindberg recorded on film ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fogging (photography)
Fogging in photography is the deterioration in the quality of the image or the negative caused either by extraneous light, other electromagnetic radiation, radioactivity or the effects of a processing chemical. It is seen either as deposition of silver or dyes across all or part of the image unrelated to the original exposure. It can be confused with chemical staining that can be produced from poorly compounded developer, contamination of processing baths or poor washing after processing. Light Light fogging is where unintended light reaches the photographic material prior to processing is seen as dark areas in the negative which tend to occur over the full width of the film including the margins. This can occur to the film in the camera because of a defect in the manufacture or use of the camera and is seen as dark areas in the negative which tend to occur over the full width of the film including the margins. In 35mm film shadowing from the sprocket holes may be seen on the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver Chloride
Silver chloride is an inorganic chemical compound with the chemical formula Ag Cl. This white crystalline solid is well known for its low solubility in water and its sensitivity to light. Upon illumination or heating, silver chloride converts to silver (and chlorine), which is signaled by grey to black or purplish coloration in some samples. AgCl occurs naturally as the mineral chlorargyrite. It is produced by a metathesis reaction for use in photography and in pH meters as electrodes. Preparation Silver chloride is unusual in that, unlike most chloride salts, it has very low solubility. It is easily synthesized by metathesis: combining an aqueous solution of silver nitrate (which is soluble) with a soluble chloride salt, such as sodium chloride (which is used industrially as a method of producing AgCl), or cobalt(II) chloride. The silver chloride that forms will precipitate immediately. : : It can also be produced by the reaction of silver metal and aqua regia; howev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Hole
In physics, chemistry, and electronic engineering, an electron hole (often simply called a hole) is a quasiparticle denoting the lack of an electron at a position where one could exist in an atom or crystal structure, atomic lattice. Since in a normal atom or crystal lattice the negative charge of the electrons is balanced by the positive charge of the atomic nucleus, atomic nuclei, the absence of an electron leaves a net positive charge at the hole's location. Holes in a metal or semiconductor crystal lattice can move through the lattice as electrons can, and act similarly to electric charge, positively-charged particles. They play an important role in the operation of semiconductor devices such as transistors, diodes (including light-emitting diodes) and integrated circuits. If an electron is excited into a higher state it leaves a hole in its old state. This meaning is used in Auger electron spectroscopy (and other x-ray techniques), in computational chemistry, and to explai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up quark, up and down quark, down quarks. Electrons are extremely lightweight particles that orbit the positively charged atomic nucleus, nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall electric charge#Charge neutrality, neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electron, valence electrons are the least tightly bound and are responsible for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that can move no faster than the speed of light measured in vacuum. The photon belongs to the class of boson particles. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While Planck was trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, he proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explain the pho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevill Francis Mott
Sir Nevill Francis Mott (30 September 1905 – 8 August 1996) was a British physicist who won the Nobel Prize for Physics in 1977 for his work on the electronic structure of magnetic and disordered systems, especially amorphous semiconductors. The award was shared with Philip W. Anderson and J. H. Van Vleck. The three had conducted loosely related research. Mott and Anderson clarified the reasons why magnetic or amorphous materials can sometimes be metallic and sometimes insulating. Education and early life Mott was born in Leeds to Charles Francis Mott and Lilian Mary Reynolds, a granddaughter of Sir John Richardson, and great granddaughter of Sir John Henry Pelly, 1st Baronet. Miss Reynolds was a Cambridge Mathematics Tripos graduate and at Cambridge was the best woman mathematician of her year. His parents met in the Cavendish Laboratory, when both were engaged in physics research under J.J. Thomson. Nevill grew up first in the village of Giggleswick, in the West ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ronald Wilfred Gurney
Ronald Wilfred (or Wilfrid) Gurney (1898– 14 April 1953) was a British theoretical physicist and research pupil of William Lawrence Bragg at the Victoria University of Manchester during the 1920s and 1930s, Bristol University during the 1930s and later in the US, where he died in New York City. He was born in Cheltenham in 1898. Radioactive decay processes Whilst at the Palmer Physical Laboratory at Princeton University from 1926 to 1928, he discovered alpha decay via quantum tunnelling, together with Edward Condon and independently of George Gamow. In the early 1900s, radioactive materials were known to have characteristic exponential decay rates or half lives. At the same time, radiation emissions were known to have certain characteristic energies. By 1928, Gamow had solved the theory of the alpha decay of a nucleus via quantum tunnelling and the problem was also solved independently by Gurney and Condon. Books *''Elementary quantum mechanics'', Cambridge ng.The University P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and image resolution, resolution of the film. Film is typically segmented in ''frames'', that give rise to separate photographs. 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 (photography), exposure to the image formed by a camera 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 in the emulsion, which can be chemically photographic processing, developed into a visible photograph. In addition to visible light, all films are sensitive to ultraviolet light, X-rays, gamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
