|
Macro Photography
Macro photography (or photomacrography or macrography, and sometimes macrophotography) is extreme close-up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life size (though ''macrophotography'' also refers to the art of making very large photographs). By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life size or greater. In some senses, however, it refers to a finished photograph of a subject that is greater than life size. The ratio of the subject size on the film plane (or sensor plane) to the actual subject size is known as the reproduction ratio. Likewise, a macro lens is classically a lens capable of reproduction ratios of at least 1:1, although it often refers to any lens with a large reproduction ratio, despite rarely exceeding 1:1. Apart from technical photography and film-based processes, where the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perspective Control Lens
Perspective may refer to: Vision and mathematics * Perspectivity, the formation of an image in a picture plane of a scene viewed from a fixed point, and its modeling in geometry ** Perspective (graphical), representing the effects of visual perspective in graphic arts ** Aerial perspective, the effect the atmosphere has on the appearance of an object as it is viewed from a distance ** Perspective distortion (photography), the way that viewing a picture from the wrong position gives a perceived distortion ** Perspective (geometry), a relation between geometric figures ** Vue d'optique or perspective view, a genre of etching popular during the second half of the 18th century and into the 19th. Entertainment * ''Perspective'' (P-Model album), 1982 * ''Perspective'' (America album), 1984 * ''Perspective'' (Jason Becker album), 1996 * ''Perspective'' (Lawson album), 2016 * ''Perspective'', a 2010 album by Prague * Perspective (EP), an EP by Tesseract * ''Perspectives'' (album), th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
View Camera
A view camera is a large-format camera in which the lens forms an inverted image on a ground-glass screen directly at the film plane. The image is viewed and then the glass screen is replaced with the film, and thus the film is exposed to exactly the same image as was seen on the screen. This type of camera was first developed in the era of the daguerreotypeStroebel, L. D. (1986). ''View Camera Technique'', 5th ed., p. 212. Boston: Focal Press. (1840s–1850s) and is still in use today, some with various drive mechanisms for movements (rather than loosen-move-tighten), more scale markings, and/or more spirit levels. It comprises a flexible bellows that forms a light-tight seal between two adjustable ''standards'', one of which holds a lens, and the other a ground glass or a photographic film holder or a digital back.Stroebel (1986). p. 2. There are three general types, the rail camera, the field camera, and others that don't fit into either category. The bellows is a flexib ... [...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 ima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
View Camera
A view camera is a large-format camera in which the lens forms an inverted image on a ground-glass screen directly at the film plane. The image is viewed and then the glass screen is replaced with the film, and thus the film is exposed to exactly the same image as was seen on the screen. This type of camera was first developed in the era of the daguerreotypeStroebel, L. D. (1986). ''View Camera Technique'', 5th ed., p. 212. Boston: Focal Press. (1840s–1850s) and is still in use today, some with various drive mechanisms for movements (rather than loosen-move-tighten), more scale markings, and/or more spirit levels. It comprises a flexible bellows that forms a light-tight seal between two adjustable ''standards'', one of which holds a lens, and the other a ground glass or a photographic film holder or a digital back.Stroebel (1986). p. 2. There are three general types, the rail camera, the field camera, and others that don't fit into either category. The bellows is a flexib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diopter
A dioptre (British spelling) or diopter (American spelling) is a unit of measurement with dimension of reciprocal length, equivalent to one reciprocal metre, 1 dioptre = 1 m−1. It is normally used to express the optical power of a lens or curved mirror, which is a physical quantity equal to the reciprocal of the focal length, expressed in metres. For example, a 3-dioptre lens brings parallel rays of light to focus at metre. A flat window has an optical power of zero dioptres, as it does not cause light to converge or diverge. Dioptres are also sometimes used for other reciprocals of distance, particularly radii of curvature and the vergence of optical beams. The main benefit of using optical power rather than focal length is that the thin lens formula has the object distance, image distance, and focal length all as reciprocals. Additionally, when relatively thin lenses are placed close together their powers approximately add. Thus, a thin 2.0-dioptre lens placed close to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge Camera
Bridge cameras are cameras that fill the niche between relatively simple point-and-shoot cameras and interchangeable-lens cameras such as mirrorless cameras and single-lens reflex cameras (SLRs). They are often comparable in size and weight to the smallest digital SLRs (DSLR), but lack interchangeable lenses, and almost all digital bridge cameras lack an optical viewfinder system. The phrase "bridge camera" has been in use at least since the 1980s, and continues to be used with digital cameras. The term was originally used to refer to film cameras which "bridged the gap" between point-and-shoot cameras and SLRs. Like other cameras, most current bridge cameras are digital. These cameras typically feature full manual controls over shutter speed, aperture, ISO sensitivity, color balance and metering. Generally, their feature sets are similar to consumer DSLRs, except for a smaller range of ISO sensitivity because of their typically smaller image sensor. Many bridge cameras ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acutance
In photography, acutance describes a subjective perception of sharpness that is related to the edge contrast of an image. Acutance is related to the amplitude of the derivative of brightness with respect to space. Due to the nature of the human visual system, an image with higher acutance appears sharper even though an increase in acutance does not increase real resolution. Historically, acutance was enhanced chemically during development of a negative (high acutance developers), or by optical means in printing (unsharp masking). In digital photography, onboard camera software and image postprocessing tools such as Photoshop or GIMP offer various sharpening facilities, the most widely used of which is known as "unsharp mask" because the algorithm is derived from the eponymous analog processing method. In the example image, two light gray lines were drawn on a gray background. As the transition is instantaneous, the line is as sharp as can be represented at this resolutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatic Aberration
In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. The refractive index of most transparent materials decreases with increasing wavelength. Since the focal length of a lens depends on the refractive index, this variation in refractive index affects focusing. Chromatic aberration manifests itself as "fringes" of color along boundaries that separate dark and bright parts of the image. Types There are two types of chromatic aberration: ''axial'' (''longitudinal''), and ''transverse'' (''lateral''). Axial aberration occurs when different wavelengths of light are focused at different distances from the lens (focus ''shift''). Longitudinal aberration is typical at long focal lengths. Transverse aberration occurs when different wavelengths are focused at different position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Close-up Lens
In photography, a close-up lens (sometimes referred to as ''close-up filter'' or a ''macro filter'') is a simple secondary lens used to enable macro photography without requiring a specialised primary lens. They work like reading glasses, allowing a primary lens to focus more closely. Bringing the focus closer allows the photographer more possibilities. Close-up lenses typically mount on the filter thread of the primary lens, and are often manufactured and sold by suppliers of photographic filters. Nonetheless, they are lenses and not photographic filter, filters. Some manufacturers refer to their close-up lenses as ''diopters'', after the unit of measurement of their optical power. Close-up lens do not affect exposure, unlike extension tubes, which also can be used for macro photography with a non-macro lens. Optical power Close-up lenses are often specified by their optical power in diopters, the reciprocal of the focal length in meters. For a close-up lens, the diopter valu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bellows (photography)
In photography, a bellows is the accordion-like, pleated expandable part of a camera, usually a large or medium format camera, to allow the lens to be moved with respect to the focal plane for focusing. Bellows are also used on enlarger An enlarger is a specialized transparency projector used to produce photographic prints from film or glass negatives, or from transparencies. Construction All enlargers consist of a light source, normally an incandescent light bulb shining thoug ...s. The bellows provides a flexible, dark extension between the film plane and the lens. In some cameras, the photographer can change the angle of the film plate with respect to the optical axis of the lens, providing alterations of perspective distortion and of the object plane of focus. Bellows may be part of a camera or come as an optional accessory. Types Two kinds of bellows are commonly used on cameras; bag bellows are normally used with a lens of short focal length, and accordion bellows wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Chromatic Aberration")
