photographic film

A photographic lens (or more correctly, objective) is an optical lens used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically. While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct the many optical aberrations that arise. There is no difference in principle between a lens used for a camera, a telescope, a microscope, or other apparatus, ...

Including:

• Photographic lens - Special purpose photographic lenses

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The cassette was a great step forward in convenience from reel-to-reel audio tape recording, though because of the limitations of the cassette's size and speed, it initially compared poorly in quality. Unlike the open reel format, the two stereo tracks lie adjacent to each other rather than a 1/3 and 2/4 arrangement. This permitted monaural cassette players to play stereo recordings "summed" as mono tracks and permitted stereo players to play mono recordings through both speakers. The tape is 3.18 mm wide (nominally 1⁄8See also:

Compact audio cassette, Compact audio cassette - Features of the cassette, Compact audio cassette - Cassette types, Compact audio cassette - Noise reduction and fidelity, Compact audio cassette - Playback length, Compact audio cassette - Write-protection, Compact audio cassette - Applications, Compact audio cassette - Audio, Compact audio cassette - Home studio, Compact audio cassette - Home dubbing, Compact audio cassette - Data recording, Compact audio cassette - Cassette equipment, Compact audio cassette - Successors to the cassette, Compact audio cassette - Present and future of the compact cassette, Compact audio cassette - Cassette in other languages

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A camera is a device used to take pictures (usually photographs), either singly or in sequence, with or without sound recording, such as with video cameras. A camera that takes pictures singly is sometimes called a photo camera to distinguish it from a video camera. The name is derived from camera obscura, Latin for "dark chamber", an early mechanism for projecting images in which an entire room functioned much as the internal workings of a modern photographic camera, except there was no way at this time to record the im ...

Including:

• Camera - Description
• Camera - History
• Camera - Camera brands

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The word grain has several meanings, most being descriptive of a small piece or particle. Grain - Particle-related. The primary definition is the agricultural one, with the others derived from it. In agriculture, a grain is the seed of a grass, a simple dry fruit technically called a caryopsis. Such crops are often called cereals. Grain can also refer to other types of small seeds, though this is technically less correct. In units of measurement, the grain is a un ...

Including:

• Grain - Particle-related
• Grain - Others

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Photography is the process of making pictures by means of the action of light. It involves recording light patterns, as reflected from objects, onto a sensitive medium through a timed exposure. The process is done through mechanical, chemical or digital devices commonly known as cameras. The word comes from the Greek words φως phos ("light"), and γραφις graphis ("stylus", "paintbrush") or γραφη graphê, together meaning "drawing with light" or "representation by means of lines" or "drawing."Including:

• Photography - Photographic image forming devices
• Photography - Uses of photography
• Photography - History of photography
• Photography - Invention
• Photography - Social history
• Photography - Economic history
• Photography - Color photography
• Photography - Digital photography
• Photography - Digital versus Film
• Photography - Commercial photography
• Photography - Terminology
• Photography - Photography as an art form
• Photography - Aesthetic realism and photography
• Photography - Reference
• Photography - Additional reading
• Photography - Basic topics in photography
• Photography - Photographers
• Photography - Photographs
• Photography - Historical
• Photography - Techniques
• Photography - Photographic products
• Photography - Other

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This article is about the American company, for the Russian company involved in a pyramid scheme, see MMM (pyramid) 3M Company NYSE: MMM (formerly Minnesota Mining and Manufacturing Company until 2002) is an American corporation with a worldwide presence that produces over 55,000 products, including adhesives, abrasives, laminates, electronic circuits and displays, and pharmaceuticals. The company was established in Two Harbors, Minnesota in 1902, then moved to Duluth, Minnesota, and finally moved to ...

Including:

• 3M - Corporate Governance
• 3M - Current Board of Directors:
• 3M - President of 3M
• 3M - Chief executive officer of 3M
• 3M - Chairman of the Board of 3M
• 3M - Alternative meanings

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The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness. The brighter the object appears the lower its value. The scale upon which magnitude is measured has its origin in the Hellenistic practice of dividing those stars visible to the naked eye into six magnitudes. The brightest stars were said to be of first magnitude (m = 1), while the faintest were of sixth magnitude (m = 6), the limit of human visual perception (without the aid of a teles ...

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Celluloid is the name of a class of compounds created from nitrocellulose and camphor, plus dyes and other agents, generally regarded to be the first thermoplastic. Easily molded and shaped, there are suggestions that celluloid was first made as an ivory replacement. Celluloid is highly flammable and also easily decomposes, and is no longer widely used. Celluloid - Nitrocellulose. Nitrocellulose-based plastics slightly predate celluloid: collodion, invented in 1848 and used as a wound dressing and emulsion ...

Including:

• Celluloid - Nitrocellulose
• Celluloid - Alexander Parkes
• Celluloid - Daniel Spill
• Celluloid - John Wesley and Isaiah Hyatt
• Celluloid - Trademark
• Celluloid - Photography
• Celluloid - Discontinuation
• Celluloid - Formulation

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Photosensitivity is the amount to which an object reacts upon receiving photons of light. Photosensitivity - Interpretation in medicine. People that are photosensitive experience discomfort or get easily sunburned when exposed to UV light, which may come from sunlight or other sources including sunbeds. This is often caused by an allergy or a medication. Heliotropism, Photosensitivity in animals Photosensitivity - Interpretation in chemistry. ...

Including:

• Photosensitivity - Interpretation in medicine
• Photosensitivity - Interpretation in chemistry

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Acetic acid, also known as ethanoic acid, is an organic chemical compound best recognized for giving vinegar its sour taste and pungent smell. Pure water-free acetic acid is a colourless hygroscopic liquid (that is, it readily absorbs water) that freezes below 16.7 °C (62 °F) to a colourless crystalline solid. Acetic acid is corrosive, and its vapour is irritating to eyes and nose, although it is a weak acid based ...

Including:

• Acetic acid - Nomenclature
• Acetic acid - History
• Acetic acid - Chemical properties
• Acetic acid - Biochemistry
• Acetic acid - Production
• Acetic acid - Methanol carbonylation
• Acetic acid - Acetaldehyde oxidation
• Acetic acid - Ethylene oxidation
• Acetic acid - Fermentation
• Acetic acid - Applications
• Acetic acid - Vinyl acetate monomer
• Acetic acid - Acetic anhydride
• Acetic acid - Ester production
• Acetic acid - Vinegar
• Acetic acid - Use as solvent
• Acetic acid - Other applications
• Acetic acid - Safety

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The compact audio cassette medium for audio storage was introduced by Philips in 1963 under the name Compact Cassette. Although there were other magnetic tape cartridge systems at the time, the Compact Cassette became dominant as a result of Philips' decision (in the face of pressure from Sony) to license the format free of charge. It went on to become a popular (and re-recordable) alternative to the vinyl record deck during the 1970s. During the 1980s, ...

Including:

• Compact audio cassette - Features of the cassette
• Compact audio cassette - Cassette types
• Compact audio cassette - Noise reduction and fidelity
• Compact audio cassette - Playback length
• Compact audio cassette - Write-protection
• Compact audio cassette - Applications
• Compact audio cassette - Audio
• Compact audio cassette - Home studio
• Compact audio cassette - Home dubbing
• Compact audio cassette - Data recording
• Compact audio cassette - Cassette equipment
• Compact audio cassette - Successors to the cassette
• Compact audio cassette - Present and future of the compact cassette
• Compact audio cassette - Cassette in other languages

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A photograph (often shortened to photo) is an image (or a representation of that on e.g. paper) created by collecting and focusing reflected electromagnetic radiation. The most common photographs are those created of reflected visible wavelengths, producing permanent records of what the human eye can see. Most photographs are made with a camera, which focuses the light onto either photographic film or a CCD or CMOS image sensor. Photographs can also be made by placing objects on photosensitive paper and exposing it to light (the result is often called a photogram) or by placing objects on the plat ...

Including:

• Photograph - History and special effects

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Plate generally refers to a thin, flat sheet, commonly of metal. There are several derivative meanings: A plate electrode in a vacuum tube. In geology, a tectonic plate is a piece of the Earth's crust; see also Plate tectonics. A plate is an item of dishware. Plate is also a mainly British, mainly antiquated term for silver-plated cutlery. In British heraldry, a plate is a roundel argent. Home plate is a piece of equipment in bas

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The anticonvulsant properties of potassium bromide were first noted by Sir Charles Locock at a meeting of the Royal Medical and Chirurgical Society in 1857. It can be regarded as the first effective medication for epilepsy. At the time, it was commonly thought that epilepsy was caused by masturbation. Locock noted that bromide calmed sexual excitement and thought this was responsible for his success in treating seizures. There would not be a better drug ...

See also:

Potassium bromide, Potassium bromide - Chemical properties, Potassium bromide - Preparation, Potassium bromide - Uses, Potassium bromide - Precautions, Potassium bromide - External Resources

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Collodion dry plates had been available use since 1855, but it was not until the invention of the gelatine dry plate in 1871 by Richard Leach Maddox that they rivaled wet plates in speed and quality. The advantages of the dry plate were obvious: photographers could use commercial dry plates off the shelf instead of having to prepare their own emulsions in a mobile darkroom. Also, for the first time, cameras could be made small enough to be hand-held, or even concealed. There was a proliferation of various designs, from single- and twin-lens reflexes to large and bulky field cameras, handheld cameras, and even cameras ...

See also:

History of the camera, History of the camera - Origins of the camera, History of the camera - Daguerreotypes and calotypes, History of the camera - Wet plates, History of the camera - Dry plates, History of the camera - Kodak and the birth of film

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Mechanisms for producing artificialy created, two-dimensional images in motion were demonstrated as early as the 1860's, including the zoetrope and the praxinoscope. These machines were outgrowths of simple optical devices (such as magic lanterns), and would display sequences of still pictures at sufficient speed for the images on the pictures to appear to be moving. Naturally, the images needed to be carefully designed to achieve the desire ...

See also:

Film, Film - History of film, Film - Origins of motion picture arts and sciences, Film - Protean developments, Film - The silent era, Film - The Sound Era & The Golden Age of Hollywood, Film - The 1940s: the war and post-war years, Film - The 1950s: Widescreen 70mm Stereo and even 3D, Film - The 1960s, Film - The 1970s, Film - The '80s: sequels blockbusters and videotape, Film - The Digital Age, Film - The '90s and new Millenium: technical advances, Film - Film theory, Film - History, Film - Specific theories styles and movements in film, Film - Film criticism, Film - The motion picture industry, Film - Stages of filmmaking, Film - Development, Film - Preproduction, Film - Production, Film - Post-production, Film - Distribution, Film - Film crew, Film - Production Team, Film - Primary Production Artists, Film - Camera and lighting, Film - Production sound, Film - Postproduction picture, Film - Postproduction sound, Film - Independent filmmaking, Film - Animation, Film - Film venues, Film - Development of film technology, Film - Endurance of films, Film - Wikibooks, Film - Basic types of film, Film - Lists, Film - Other

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The key instrument of nearly all modern observational astronomy is the telescope. This serves the dual purposes of gathering more light so that very faint objects can be observed, and magnifying the image so that small and distant objects can be observed. The optics used in a telescope have very exacting requirements which require great precision in their construction. Typical requirements for grinding and polishing a curved mirror, for example, require the surface to be within a f ...

See also:

Observational astronomy, Observational astronomy - Unaided eye, Observational astronomy - Telescopes, Observational astronomy - Optical telescopes, Observational astronomy - Other instruments, Observational astronomy - Observation tools, Observational astronomy - Observing, Observational astronomy - Related lists

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Potassium iodide may also be used to protect the thyroid from radioactive iodine in the event of an accident or terroist attack at a nuclear power plant, or other nuclear attack, especially where a nuclear reactor is breached and the volatile radionuclides, which contain significant amount of 131I, are released into the environment. Radioiodine is a particularly dangerous radionuclide because the body concentrates it in the thyroid gland. Potassium iodide cannot protect against other causes of radiation poisoning, however, nor can it provide any degree of protection ...

See also:

Potassium iodide, Potassium iodide - Chemical properties, Potassium iodide - Preparation, Potassium iodide - Uses, Potassium iodide - Role of potassium iodide in radiological emergency preparedness, Potassium iodide - Precautions, Potassium iodide - Suppliers/Manufacturers

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Rubidium (L rubidus, deepest red) was discovered in 1861 by Robert Bunsen and Gustav Kirchhoff in the mineral lepidolite through the use of a spectroscope. However this element had minimal industrial use until the 1920s. Historically, the most important use for rubidium has been in research and development, primarily in chemical and electronic applications. Rubidium is used for polarizing 3He. Polarized Rb polarizes 3He by hyperfine interaction. Polarized 3He cell ...

See also:

Rubidium, Rubidium - Notable characteristics, Rubidium - Applications, Rubidium - History, Rubidium - Occurrence, Rubidium - Isotopes, Rubidium - Precautions, Rubidium - Biological Effects

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Photography - Invention. Main articles: History of the camera, and [[]], and [[]], and [[]]See also:

Photography, Photography - Photographic image-forming devices, Photography - Uses of photography, Photography - History of photography, Photography - Invention, Photography - Social history, Photography - Economic history, Photography - Color photography, Photography - Digital photography, Photography - Digital versus film, Photography - Commercial photography, Photography - Terminology, Photography - Photography as an art form, Photography - Aesthetic realism and photography, Photography - Reference, Photography - Additional reading, Photography - Basic topics in photography, Photography - Photographers, Photography - Photographs, Photography - Historical, Photography - Techniques, Photography - Photographic products, Photography - Other

Read more here: » Photography: Encyclopedia II - Photography - History of photography