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Pinhole Photography
A pinhole camera is a simple camera without a lens but with a tiny aperture (the so-called ''pinhole'')—effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect. The size of the images depends on the distance between the object and the pinhole. History Camera obscura The camera obscura or pinhole image is a natural optical phenomenon. Early known descriptions are found in the Chinese Mozi writings (circa 500 BCE) and the Aristotelian ''Problems'' (circa 300 BCE – 600 CE). Ibn al-Haytham (965–1039), an Arab physicist also known as Alhazen, described the camera obscura effect. Over the centuries others started to experiment with it, mainly in dark rooms with a small opening in shutters, mostly to study the nature of light and to safely watch solar eclipses. Giambattista Della Porta wrote in 1558 in his Magia Nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Kennedy Dickson
William Kennedy Laurie Dickson (3 August 1860 – 28 September 1935) was a British people, British inventor who devised an early motion picture camera under the employment of Thomas Edison. Early life William Kennedy Dickson was born on 3 August 1860 in Le Minihic-sur-Rance, Brittany, France. His mother was Elizabeth Kennedy-Laurie (1823?–1879) who may have been born in Virginia. His father was James Waite Dickson, a Scottish artist, astronomer and linguist. James Dickson claimed direct lineage from the painter William Hogarth, and from Judge John Waite, the man who sentenced Charles I of England, King Charles I to death. Inventor and film innovator At age 19 in 1879, William Dickson wrote a letter to American inventor and entrepreneur Thomas Edison seeking employment. He was turned down. That same year Dickson, his mother, and two sisters moved from Britain to Virginia. In 1883 he was finally hired to work at Edison's laboratory in Menlo Park, New Jersey. In 1888, Ediso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distortion (optics)
In geometric optics, distortion is a deviation from rectilinear projection; a projection in which straight lines in a scene remain straight in an image. It is a form of aberration in optical systems, optical aberration. Radial distortion Although distortion can be irregular or follow many patterns, the most commonly encountered distortions are radially symmetric, or approximately so, arising from the symmetry of a photographic lens. These ''radial distortions'' can usually be classified as either ''barrel'' distortions or ''pincushion'' distortions. Mathematically, barrel and pincushion distortion are quadratic function, quadratic, meaning they increase as the ''square'' of distance from the center. In mustache distortion the quartic function, quartic (degree 4) term is significant: in the center, the degree 2 barrel distortion is dominant, while at the edge the degree 4 distortion in the pincushion direction dominates. Other distortions are in principle possible ... [...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] |
Pinhead Mirror
A pinhead mirror can be used to create a camera similar to a pinhole camera. Instead of passing through a tiny aperature, the light to form the image is reflected by a small disc-shaped mirror (with a diameter the same as that of a pinhole; about 0.15 mm - 0.4 mm). One advantage is that a pinhead mirror can be swiveled to scan a scene or project a scene to different locations. Pinhead mirror technology was protected under US patent 4,948,211 - "Method and Apparatus for Optical Imaging Medical optical imaging is the use of light as an investigational :wikt:imaging, imaging technique for medical applications. Examples include optical microscopy, spectroscopy, endoscopy, scanning laser ophthalmoscopy, laser Doppler imaging, and opti ... Using a Small, Flat Reflecting Surface" until the patent expired in 2009. References * TH Nilsson (1986) "The Pinhead mirror: A previously undiscovered imaging device?" ''Applied Optics'', 25, 2863-2864 * TH Nilsson (1987) "Pinhead mirro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinspeck Camera
A pinspeck camera is the optical reverse of a pinhole camera A pinhole camera is a simple camera without a lens but with a tiny aperture (the so-called ''pinhole'')—effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image o ...: a small (point-like) obstruction (the speck) is placed in front of the film where the (pin) hole would be in a pinhole camera. (The dark screen is “replaced” by the transparent nothing around the speck.) Whereas in a pinhole camera the hole allows rays of light from different parts of the scene to reach different parts of the film, the obstruction in the pinspeck camera causes the ''shadow'' of different points in the scene to fall on different points on the film. The result is a negative image. External links Jearl Walker ''The Pleasure of the Pin Hole Camera and Its Relative the Pinspeck Camera''* Adam Lloyd Cohen ''Anti-pinhole imaging'' Optica Acta: International J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surveillance
Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing or directing. This can include observation from a distance by means of electronic equipment, such as closed-circuit television (CCTV), or interception of electronically transmitted information like Internet traffic. It can also include simple technical methods, such as Human intelligence (intelligence gathering), human intelligence gathering and postal interception. Surveillance is used by citizens for protecting their neighborhoods. And by governments for intelligence gathering - including espionage, prevention of crime, the protection of a process, person, group or object, or the investigation of crime. It is also used by criminal organizations to plan and commit crimes, and by businesses to Industrial espionage, gather intelligence on criminals, their competitors, suppliers or customers. Religious organisations charged with detecting he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charge-coupled Device
A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a major technology used in digital imaging. In a CCD image sensor, pixels are represented by p-doped metal–oxide–semiconductor (MOS) capacitors. These MOS capacitors, the basic building blocks of a CCD, are biased above the threshold for inversion when image acquisition begins, allowing the conversion of incoming photons into electron charges at the semiconductor-oxide interface; the CCD is then used to read out these charges. Although CCDs are not the only technology to allow for light detection, CCD image sensors are widely used in professional, medical, and scientific applications where high-quality image data are required. In applications with less exacting quality demands, such as consumer and professional digital cameras, act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solarigraphy
Solarigraphy is a concept and a photographic practice based on the observation of the sun path in the sky (different in each place on the Earth) and its effect on the landscape, captured by a specific procedure that combines pinhole photography and digital processing. Invented around 2000, solarigraphy (also known as solargraphy) uses photographic paper without chemical processing, a pinhole camera and a scanner to create images that catch the daily journey of the sun along the sky with very long exposure times, from several hours to several years. The longest known solarigraph was captured over the course of eight years. Solarigraphy is an extreme case of long-exposure photography, and the non-conventional use of photosensitive materials is what makes it different to other methods of sun paths capture such as the Yamazaki´s "heliographys" Beginnings In 2000, Diego López Calvín, Sławomir Decyk and Paweł Kula started a global and synchronized photographic work known as ... [...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. 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 rays, and particle radiation, high-energy particles. Unmodified silver halide crys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integral Photography
Integral imaging is a three-dimensional imaging technique that captures and reproduces a light field by using a two-dimensional array of microlenses (or lenslets), sometimes called a fly's-eye lens, normally without the aid of a larger overall objective or viewing lens. In capture mode, in which a film or detector is coupled to the microlens array, each microlens allows an image of the subject as seen from the viewpoint of that lens's location to be acquired. In reproduction mode, in which an object or source array is coupled to the microlens array, each microlens allows each observing eye to see only the area of the associated micro-image containing the portion of the subject that would have been visible through that space from that eye's location. The optical geometry can perhaps be visualized more easily by substituting pinholes for the microlenses, as has actually been done for some demonstrations and special applications. A display using integral imaging is a type of light field ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eugène Estanave
Eugene is a common male given name that comes from the Greek εὐγενής (''eugenēs''), "noble", literally "well-born", from εὖ (''eu''), "well" and γένος (''genos''), "race, stock, kin". Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus Gene is a common shortened form. The feminine variant is or Eugenie. , a common given name in parts of central and northern Europe, is also a variant of Eugene / Eugine. Other male foreign-language variants in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
