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Seagull Camera
Shanghai Seagull Camera Ltd is a Chinese camera maker located in Shanghai, China. Founded in 1958, Seagull is the oldest camera maker in China. The product line of Seagull includes TLR cameras, SLR cameras, folding cameras, CCD and SLR camera lenses, large-format cameras, film, night vision scopes, and angle viewfinders. Seagull's cameras usually use basic, time-tested mechanical designs that require no batteries. Some Seagull cameras are distributed through the Lomography company. Seagull adopted the SR lens mount from Minolta's manual focus SLRs and camera design under license, and continues to produce it long after Minolta moved on to autofocus Alpha lens mount cameras. In 2009 a fixfocus-Digital camera DS-5060S with 5 MB-sensor was offered. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seagull 4BI Front
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, most gulls were placed in the genus ''Larus'', but that arrangement is now considered polyphyletic, leading to the resurrection of several genera. An older name for gulls is mews, which is cognate with German ''Möwe'', Danish ''måge'', Swedish ''mås'', Dutch ''meeuw'', Norwegian ''måke''/''måse'' and French ''mouette'', and can still be found in certain regional dialects. Gulls are typically medium to large in size, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls; stout, longish bills; and webbed feet. Most gulls are ground-nesting carnivores which take live food or scavenge opportunistically, particularly the ''Larus'' species. Live food often includes crustac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autofocus
An autofocus (or AF) optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system has to be done manually until indication. Autofocus methods are distinguished as active, passive or hybrid types. Autofocus systems rely on one or more sensors to determine correct focus. Some AF systems rely on a single sensor, while others use an array of sensors. Most modern SLR cameras use through-the-lens optical sensors, with a separate sensor array providing light metering, although the latter can be programmed to prioritize its metering to the same area as one or more of the AF sensors. Through-the-lens optical autofocusing is usually speedier and more precise than manual focus with an ordinary viewfinder, although more precise manual focus can be achieved with special accessories such as focusing magnifiers. Autofocus ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens Manufacturers
A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), usually arranged along a common axis. Lenses are made from materials such as glass or plastic, and are ground and polished or molded to a desired shape. A lens can focus light to form an image, unlike a prism, which refracts light without focusing. Devices that similarly focus or disperse waves and radiation other than visible light are also called lenses, such as microwave lenses, electron lenses, acoustic lenses, or explosive lenses. Lenses are used in various imaging devices like telescopes, binoculars and cameras. They are also used as visual aids in glasses to correct defects of vision such as myopia and hypermetropia. History The word ''lens'' comes from '' lēns'', the Latin name of the lentil (a seed of a lentil plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manufacturing Companies Based In Shanghai
Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of secondary sector of the economy. The term may refer to a range of human activity, from handicraft to high-tech, but it is most commonly applied to industrial design, in which raw materials from the primary sector are transformed into finished goods on a large scale. Such goods may be sold to other manufacturers for the production of other more complex products (such as aircraft, household appliances, furniture, sports equipment or automobiles), or distributed via the tertiary industry to end users and consumers (usually through wholesalers, who in turn sell to retailers, who then sell them to individual customers). Manufacturing engineering is the field of engineering that designs and optimizes the manufacturing process, or the steps through which raw materials are transformed into a final produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photography Companies Of China
Photography is the art, application, and practice of creating durable 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. 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 is an invisible latent image, which is later chemically "developed" into a visible image, either negative or positive, depending on the purpose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cultural Revolution
The Cultural Revolution, formally known as the Great Proletarian Cultural Revolution, was a sociopolitical movement in the People's Republic of China (PRC) launched by Mao Zedong in 1966, and lasting until his death in 1976. Its stated goal was to preserve Chinese communism by purging remnants of capitalist and traditional elements from Chinese society. The Revolution marked the effective commanding return of Mao –who was still the Chairman of the Chinese Communist Party (CCP)– to the centre of power, after a period of self-abstention and ceding to less radical leadership in the aftermath of the Mao-led Great Leap Forward debacle and the Great Chinese Famine (1959–1961). The Revolution failed to achieve its main goals. Launching the movement in May 1966 with the help of the Cultural Revolution Group, Mao charged that bourgeois elements had infiltrated the government and society with the aim of restoring capitalism. Mao called on young people to " bombard the hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seagull 205 (4) (7845667518)
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, most gulls were placed in the genus ''Larus'', but that arrangement is now considered polyphyletic, leading to the resurrection of several genera. An older name for gulls is mews, which is cognate with German ''Möwe'', Danish ''måge'', Swedish ''mås'', Dutch ''meeuw'', Norwegian ''måke''/''måse'' and French ''mouette'', and can still be found in certain regional dialects. Gulls are typically medium to large in size, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls; stout, longish bills; and webbed feet. Most gulls are ground-nesting carnivores which take live food or scavenge opportunistically, particularly the ''Larus'' species. Live food often includes crustac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooke Triplet
The Cooke triplet is a photographic lens designed and patented (patent number GB 22,607) in 1893 by Dennis Taylor who was employed as chief engineer by T. Cooke & Sons of York. It was the first lens system that allowed elimination of most of the optical distortion or aberration at the outer edge of the image. The Cooke triplet is noted for being able to correct the Seidel aberrations. It is recognized as one of the most important objective designs in the field of photography. The lens designed, invented by Dennis Taylor but named for the firm he worked for, consists of three separated lens elements. It has two biconvex lenses on the outer and a biconcave lens in the middle. The design took a new approach to solving the optical design issues, and the design was presented to the Optical Society of London. Design A Cooke triplet comprises a negative flint glass element in the centre with a crown glass element on each side. In this design, the sum of all the curvatures tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresnel Lens
A Fresnel lens ( ; ; or ) is a type of composite compact lens developed by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses. It has been called "the invention that saved a million ships." The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet. The simpler dioptric (purely refractive) form of the lens was first proposed by Count Buffon and independently reinvented by Fresnel. The '' catadioptric'' form of the lens, entirely invented by Fresnel, has outer elements that use total internal reflection as well as refraction; it can capture more oblique light from a light source and add it to the beam of a lighthouse, making the light visible from greater distances. Description The Fresnel len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Shoe
Canon EOS 350D Hot shoe Proprietary hot shoe used by Minolta and older Sony cameras (Konica Minolta Maxxum 7D)">Sony">Minolta and older Sony cameras (Konica Minolta Maxxum 7D">Sony.html" ;"title="Minolta and older Sony">Minolta and older Sony cameras (Konica Minolta Maxxum 7D) A hot shoe is a mounting point on the top of a camera to attach a flash (photography), flash unit and other compatible accessories. It takes the form of an angled metal bracket surrounding a metal contact point which completes an electrical connection between camera and accessory for standard, brand-independent flash synchronization. The hot shoe is a development of the standardised "accessory shoe", with no flash contacts, formerly fitted to cameras to hold accessories such as a rangefinder, or flash connected by a cable. The dimensions of the hot shoe are defined by the International Organization for Standardization in ISO 518:2006. Details such as trigger voltage are not standardised; electrical inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tessar
The Tessar is a photographic lens design conceived by the German physicist Paul Rudolph in 1902 while he worked at the Zeiss optical company and patented by Zeiss in Germany; the lens type is usually known as the Zeiss Tessar. A Tessar comprises four elements in three groups, one positive crown glass element at the front, one negative flint glass element at the center and a negative plano-concave flint glass element cemented with a positive convex crown glass element at the rear. History Beginnings Despite common belief, the Tessar was not developed from the 1893 Cooke triplet design by replacing the rear element with a cemented achromatic doublet. Paul Rudolph designed the Anastigmat with two lenses cemented in 1890. Later, Rudolph thought that a narrow airgap in the form of a positive lens would correct the spherical aberration (as did HL Aldis in 1895) and that this device was much better than the lenses cemented. In addition, this allowed the photographers to ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twin-lens Reflex Camera
A twin-lens reflex camera (TLR) is a type of camera with two objective lenses of the same focal length. One of the lenses is the photographic objective or "taking lens" (the lens that takes the picture), while the other is used for the viewfinder system, which is usually viewed from above at waist level. In addition to the objective, the viewfinder consists of a 45-degree mirror (the reason for the word ''reflex'' in the name), a matte focusing screen at the top of the camera, and a pop-up hood surrounding it. The two objectives are connected, so that the focus shown on the focusing screen will be exactly the same as on the film. However, many inexpensive 'pseudo' TLRs are fixed-focus models. Most TLRs use leaf shutters with shutter speeds up to 1/500 of a second with a bulb setting. For practical purposes, all TLRs are film cameras, most often using 120 film, although there are many examples which used 620 film, 127 film, and 35 mm film. Few general-purpose digital TLR ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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