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Large Format (photography)
Large format refers to any imaging format of or larger. Large format is larger than "medium format", the or size of Hasselblad, Mamiya, Rollei, Kowa, and Pentax cameras (using 120- and 220-roll film), and much larger than the frame of 35 mm format. The main advantage of a large format, film or digital, is a higher resolution at the same pixel pitch, or the same resolution with larger pixels or grains which allows each pixel to capture more light enabling exceptional low-light capture. A 4×5 inch image (12.903 mm²) has about 15 times the area, and thus 15× the total resolution, of a 35 mm frame (864 mm²). Large format cameras were some of the earliest photographic devices, and before enlargers were common, it was normal to just make 1:1 contact prints from a 4×5, 5×7, or 8×10-inch negative. Formats The most common large format is 4×5 inches (10.2x12.7 cm), which was the size used by cameras like the Graflex Speed Graphic and Crown Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polaroid 20×24 Camera
The Polaroid 20×24 camera is a very large instant camera made by Polaroid, with film plates that measure a nominal , giving the camera its name, although at least one camera takes pictures that are . Design The Polaroid 20×24 is one of the largest format cameras currently in common use, and could be hired from Polaroid agents in various countries. A plexiglass sheet is taped to the front of the lens, and the subject uses their reflection to help determine where they are in the frame. Because of the size of the image, acquiring an image with sufficient depth of field can be a challenge, and the lens (the camera at 20×24 Studio in New York City was fitted with a Fujinon-A 600 mm 11 lens) is often stopped down to 90. Lenses were available in a variety of focal lengths ranging from 135 mm to 1200 mm, but only the 600 mm, 800 mm, and 1200 mm lenses were designed for the 20×24 format. The 20×24 is collapsible for storage and transport like a field camera: the bellows are compress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Glass
Ground glass is glass whose surface has been ground to produce a flat but rough (matte) finish, in which the glass is in small sharp fragments. Ground glass surfaces have many applications, ranging from ornamentation on windows and table glassware to scientific uses in optics and laboratory glassware. Uses Photography In photography, a sheet of ground glass is used for the manual focusing in some still and movie cameras; the ground-glass viewer is inserted in the back of the camera, and the lens opened to its widest aperture. This projects the scene on the ground glass upside down. The photographer focuses and composes using this projected image, sometimes with the aid of a magnifying glass (or loupe). In order to see the image better, a dark cloth is used to block out light, whence came the image of the old-time photographer with his head stuck under a large black cloth. A ground glass is also used in the reflex finder of an SLR or TLR camera. In motion-picture cameras, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rangefinder
A rangefinder (also rangefinding telemeter, depending on the context) is a device used to measure distances to remote objects. Originally optical devices used in surveying, they soon found applications in other fields, such as photography and in the military. They were specially useful for finding the range of a target, such as in naval gunnery and anti-aircraft artillery. The word ''telemeter'' is derived . Designs The first rangefinder telemeter was invented by James Watt in 1769 and put to use in 1771 in surveying canals. Watt called his instrument a micrometer, a term now used with a different meaning in engineering (the micrometer screw gauge). It consisted of two parallel hairs in the focal plane of a telescope eyepiece crossing an upright hair. At the point to be measured, two sliding targets on a surveyor's rod were adjusted to align with the hairs in the telescope. The distance to the rod could then be determined from the distance between the targets on the ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tripod
A tripod is a portable three-legged frame or stand, used as a platform for supporting the weight and maintaining the stability of some other object. The three-legged (triangular stance) design provides good stability against gravitational loads as well as horizontal shear forces, and better leverage for resisting tipping over due to lateral forces can be achieved by spreading the legs away from the vertical centre. Variations with one, two, and four legs are termed ''monopod'', ''bipod'', and ''quadripod'' (similar to a table). Etymology First attested in English in the early 17th century, the word ''tripod'' comes via Latin ''tripodis'' (GEN of ''tripus''), which is the romanization of Greek (''tripous''), "three-footed" (GEN , ''tripodos''), ultimately from (''tri-''), "three times" (from , ''tria'', "three") + (''pous''), "foot". The earliest attested form of the word is the Mycenaean Greek , ''ti-ri-po'', written in Linear B syllabic script. Cultural use Many cultur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darkroom
A darkroom is used to process photographic film, to make prints and to carry out other associated tasks. It is a room that can be made completely dark to allow the processing of the light-sensitive photographic materials, including film and photographic paper. Various equipment is used in the darkroom, including an enlarger, baths containing chemicals, and running water. Darkrooms have been used since the inception of photography in the early 19th century. Darkrooms have many various manifestations, from the elaborate space used by Ansel Adams to a retooled ambulance wagon used by Timothy H. O'Sullivan. From the initial development of the film to the creation of prints, the darkroom process allows complete control over the medium. Due to the popularity of color photography and complexity of processing color film (''see C-41 process'') and printing color photographs and also to the rise, first of instant photography technology and later digital photography, darkrooms are dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Changing Bag
A changing bag is a photographic bag specifically designed to be light-proof while in use. It is required for certain applications involving photosensitive materials when a darkroom is not available, like in the field. Common usages include removing film from its canister to put it into a developing tank, or loading and unloading sheet film holders. They are also commonly found on the set of a film, where the clapper loader may need one if shooting on location or far away from a darkroom. Usage It is handy to use when a darkroom is not available as is often the case in field shooting. It is also used in commercial photo processing labs, often to change paper. Description A changing bag has two sleeves at one end for both the user's arms, and a zipper (often more than one, for double layered changing bags) to insert the tools and film needed. There are several sizes available, from smaller ones for many still photography applications to larger bags used in large-format still phot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Film Plane
A film plane is the surface of an image recording device such as a camera, upon which the lens creates the focused image. In cameras from different manufacturers, the film plane varies in distance from the lens. Thus each lens used has to be chosen carefully to assure that the image is focused on the exact place where the individual frame of film or digital sensor is positioned during exposure. It is sometimes marked on a camera body with the 'Φ' symbol where the vertical bar represents the exact location. Movie cameras often also have small focus hooks where the focus puller can attach one side of a tape measure to quickly gauge the distance to objects that he intends to bring into focus. The measurement is taken from the film plane to the subject. Due to Petzval field curvature, the film plane upon which a lens focuses may not be a literal plane. Cameras may bend the film stock or even plate stock slightly to compensate, improving the area of critical focus and sharpness. Nev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group f/64
Group 64 or f.64 was a group founded by seven 20th-century San Francisco Bay Area photographers who shared a common photographic style characterized by sharply focused and carefully framed images seen through a particularly Western (U.S.) viewpoint. In part, they formed in opposition to the pictorialist photographic style that had dominated much of the early 20th century, but moreover, they wanted to promote a new modernist aesthetic that was based on precisely exposed images of natural forms and found objects. Background The late 1920s and early 1930s were a time of substantial social and economic unrest in the United States. The United States was suffering through the Great Depression, and people were seeking some respite from their everyday hardships. The American West was seen as the base for future economic recovery because of massive public works projects like the Hoover Dam. The public sought out news and images of the West because it represented a land of hope in an other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ansel Adams
Ansel Easton Adams (February 20, 1902 – April 22, 1984) was an American landscape photographer and environmentalist known for his black-and-white images of the American West. He helped found Group f/64, an association of photographers advocating "pure" photography which favored sharp focus and the use of the full tonal range of a photograph. He and Fred Archer developed an exacting system of image-making called the Zone System, a method of achieving a desired final print through a deeply technical understanding of how tonal range is recorded and developed during exposure, negative development, and printing. The resulting clarity and depth of such images characterized his photography. Adams was a life-long advocate for environmental conservation, and his photographic practice was deeply entwined with this advocacy. At age 12, he was given his first camera during his first visit to Yosemite National Park. He developed his early photographic work as a member of the Sierra C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scheimpflug Principle
The Scheimpflug principle is a description of the geometric relationship between the orientation of the plane of focus, the lens plane, and the image plane of an optical system (such as a camera) when the lens plane is not parallel to the image plane. It is applicable to the use of some camera movements on a view camera. It is also the principle used in corneal pachymetry, the mapping of corneal topography, done prior to refractive eye surgery such as LASIK, and used for early detection of keratoconus. The principle is named after Austrian army Captain Theodor Scheimpflug, who used it in devising a systematic method and apparatus for correcting perspective distortion in aerial photographs, although Captain Scheimpflug himself credits Jules Carpentier with the rule, thus making it an example of Stigler's law of eponymy. Description Normally, the lens and image (film or sensor) planes of a camera are parallel, and the plane of focus (PoF) is parallel to the lens and image ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depth Of Field
The depth of field (DOF) is the distance between the nearest and the furthest objects that are in acceptably sharp focus in an image captured with a camera. Factors affecting depth of field For cameras that can only focus on one object distance at a time, depth of field is the distance between the nearest and the farthest objects that are in acceptably sharp focus. "Acceptably sharp focus" is defined using a property called the "circle of confusion". The depth of field can be determined by focal length, distance to subject, the acceptable circle of confusion size, and aperture. Limitations of depth of field can sometimes be overcome with various techniques and equipment. The approximate depth of field can be given by: : \text \approx \frac for a given circle of confusion (c), focal length (f), f-number (N), and distance to subject (u). As distance or the size of the acceptable circle of confusion increases, the depth of field increases; however, increasing the size of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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