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Glare (vision)
Glare is difficulty of seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night. Because of this, some cars include mirrors with automatic anti-glare functions and in buildings, blinds or louvers are often used to protect occupants. Glare is caused by a significant ratio of luminance between the task (that which is being looked at) and the glare source. Factors such as the angle between the task and the glare source and eye adaptation have significant impacts on the experience of glare. Discomfort and disability Glare can be generally divided into two types, discomfort glare and disability glare. Discomfort glare is a psychological sensation caused by high brightness (or brightness contrast) within the field of view, which does not necessarily impair vision. In buildings, discomfort glare can originate from small artificial lights (e.g. ceiling fixtures) that have brightnesses that are significantly greater tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flashlight Effect Sumo Jan08
A flashlight (American English, US English) or electric torch (Commonwealth English), usually shortened to torch, is a portable hand-held electric lamp. Formerly, the light source typically was a miniature incandescent light bulb, but these have been displaced by light-emitting diodes (LEDs) since the early 2000s. A typical flashlight consists of the light source mounted in a reflector, a transparent cover (sometimes combined with a Lens (optics), lens) to protect the light source and reflector, a battery (electricity), battery, and a switch, all enclosed in a case. The invention of the dry cell and miniature incandescent electric lamps made the first battery-powered flashlights possible around 1899. Today, flashlights use mostly light-emitting diodes and run on Disposable battery, disposable or rechargeable battery, rechargeable batteries. Some are powered by the user turning a Crank (mechanism), crank, shaking the lamp, or squeezing it. Some have solar panels to recharge the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminance Meter
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls within a given solid angle. The procedure for conversion from spectral radiance to luminance is standardized by the CIE and ISO. Brightness is the term for the ''subjective'' impression of the ''objective'' luminance measurement standard (see for the importance of this contrast). The SI unit for luminance is candela per square metre (cd/m2). A non-SI term for the same unit is the nit. The unit in the Centimetre–gram–second system of units (CGS) (which predated the SI system) is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. Description Luminance is often used to characterize emission or reflection from flat, diffuse surfaces. Luminance levels indicate how much luminous power could be detected b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyot Stop
A Lyot stop (also called a glare stop) is an optical stop, invented by French astronomer Bernard Lyot, that reduces the amount of flare caused by diffraction of other stops and baffles in optical systems. Lyot stops are located at images of the system's entrance pupil and have a diameter slightly smaller than the pupil's image. Examples of applications can be found in Ref. See also * Lyot filter * Lyot depolarizer * Coronagraph A coronagraph is a telescopic attachment designed to block out the direct light from a star or other bright object so that nearby objects – which otherwise would be hidden in the object's bright glare – can be resolved. Most coronagr ... References External linksNASA Coronagraphs by Bass et al. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens Flare
A lens flare happens when light is scattered, or ''flared'', in a lens system, often in response to a bright light, producing a sometimes undesirable artifact in the image. This happens through light scattered by the imaging mechanism itself, for example through internal reflection and forward scatter from material imperfections in the lens. Lenses with large numbers of elements such as zooms tend to have more lens flare, as they contain a relatively large number of interfaces at which internal scattering may occur. These mechanisms differ from the focused image generation mechanism, which depends on rays from the refraction of light from the subject itself. There are two types of flare: visible artifacts and glare across the image. The glare makes the image look "washed out" by reducing contrast and color saturation (adding light to dark image regions, and adding white to saturated regions, reducing their saturation). Visible artifacts, usually in the shape of the apert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afterimage
An afterimage, or after-image, is an image that continues to appear in the eyes after a period of exposure to the original image. An afterimage may be a normal phenomenon (physiological afterimage) or may be pathological (palinopsia). Illusory palinopsia may be a pathological exaggeration of physiological afterimages. Afterimages occur because Photochemistry, photochemical activity in the retina continues even when the eyes are no longer experiencing the original stimulus. The remainder of this article refers to physiological afterimages. A common physiological afterimage is the dim area that seems to float before one's human eye, eyes after briefly looking into a light source, such as a camera flash. Palinopsia is a common symptom of visual snow. Negative afterimages Negative image, Negative afterimages are generated in the retina but may be modified like other retinal signals by neural adaptation of the retinal ganglion cells that carry signals from the retina of the eye to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freiburg Im Breisgau
Freiburg im Breisgau or simply Freiburg is the List of cities in Baden-Württemberg by population, fourth-largest city of the German state of Baden-Württemberg after Stuttgart, Mannheim and Karlsruhe. Its built-up area has a population of about 355,000 (2021), while the greater Freiburg metropolitan area ("Einzugsgebiet") has about 660,000 (2018). Freiburg is located at the southwestern foothills of the Black Forest, on the Dreisam River, a tributary of the Elz (Rhine), Elz. It is Germany's southwestern- and southernmost city with a population exceeding 100,000. It lies in the Breisgau, one of Germany's warmest regions, in the south of the Upper Rhine Plain. Its city limits reach from the Schauinsland summit () in the Black Forest to east of the French border, while Switzerland is to the south. The city is situated in the major Baden (wine region), wine-growing region of Baden and, together with Offenburg, serves as a tourist entry-point to the scenic Black Forest. According ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copenhagen
Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the Øresund strait. The Øresund Bridge connects the two cities by rail and road. Originally a Vikings, Viking fishing village established in the 10th century in the vicinity of what is now Gammel Strand, Copenhagen became the capital of Denmark in the early 15th century. During the 16th century, the city served as the ''de facto'' capital of the Kalmar Union and the seat of the Union's monarchy, which governed most of the modern-day Nordic countries, Nordic region as part of a Danish confederation with Sweden and Norway. The city flourished as the cultural and economic centre of Scandinavia during the Renaissance. By the 17th century, it had become a regional centre of power, serving as the heart of the Danish government and Military history ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Climate
Tropical climate is the first of the five major climate groups in the Köppen climate classification identified with the letter A. Tropical climates are defined by a monthly average temperature of or higher in the coolest month, featuring hot temperatures and high humidity all year-round. Annual precipitation is often abundant in tropical climates, and shows a seasonal rhythm but may have seasonal dryness to varying degrees. There are normally only two seasons in tropical climates, a wet (rainy/monsoon) season and a dry season. The annual temperature range in tropical climates is normally very small. Sunlight is intense in these climates. There are three basic types of tropical climates within the tropical climate group: tropical rainforest climate (Af), tropical monsoon climate (Am) and Tropical savanna climate, tropical savanna or tropical wet and dry climate (Aw for dry winters, and As for dry summers), which are classified and distinguished by the precipitation levels of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Standards Organisation
The European Committee for Standardization (CEN, ) is a public standards organization whose mission is to foster the economy of the European Single Market and the wider European continent in global trading, the welfare of European citizens and the environment by providing an efficient infrastructure to interested parties for the development, maintenance and distribution of coherent sets of standards and specifications. The CEN was founded in 1961. Its thirty-four national members work together to develop European Standards (ENs) in various sectors to build a European internal market for goods and services and to position Europe in the global economy. CEN is officially recognized as a European standards body by the European Union, European Free Trade Association and the United Kingdom; the other official European standards bodies are the European Committee for Electrotechnical Standardization (CENELEC) and the European Telecommunications Standards Institute (ETSI). More than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illuminance
In photometry (optics), photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception.International Electrotechnical Commission (IEC): ''International Electrotechnical Vocabulary.'ref. 845-21-060, illuminance/ref> Similarly, luminous emittance is the luminous flux per unit area emitted from a surface. Luminous emittance is also known as luminous exitance. In SI derived units, SI units illuminance is measured in lux (lx), or equivalently in lumen (unit), lumens per square metre (Lumen (unit), lm·meter, m−2). Luminous exitance is measured in lm·m−2 only, not lux. International Electrotechnical Commission (IEC): ''International Electrotechnical Vocabulary.'ref. 845-21-081, luminous exitance/ref> In the CGS system, the unit of illuminance is the phot, which is equal to . The foot-candle is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daylight
Daylight is the combination of all direct and indirect sunlight during the daytime. This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected by Earth and terrestrial objects, like landforms and buildings. Sunlight scattering, scattered or reflected by astronomical objects is generally not considered daylight. Therefore, daylight excludes moonlight, despite it being reflected indirect sunlight. Definition Daylight is present at a particular location, to some degree, whenever the Sun is above the local horizon. This is true for slightly more than 50% of the Earth at any given time, since the Earth's atmosphere refracts some sunlight even when the Sun is below the horizon. Outdoor illuminance varies from 120,000 lux for direct sunlight at noon, which may cause eye pain, to less than 5 lux for thick storm clouds with the Sun at the horizon (even <1 lux for the most extreme case), which may make shadows from distant street lights visible. It may be d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guth Position Index
Guth is a surname. Notable people with the surname include: * Alan Guth (born 1947), American cosmologist * Alfred Guth (1908–1996), Austrian-born American water polo player, swimmer, and Olympic modern pentathlete * Allison Guth (born 1981/2), American basketball coach * Amy Guth, American radio host and writer * Bucky Guth (born 1966), American baseball player * Charles Guth (1876–1948), American businessman * Charlie Guth (1856–1883), American baseball player * Claus Guth (born 1964) German theatre director, focused on opera * Dana Guth (born 1970), German politician * Dennis Guth (born 1955), American politician * Eugene Guth (1905–1990), Hungarian-American physicist * Fernand Guth (1926–1977), Luxembourgish footballer * Henk Guth (c.1921–2003), Dutch artist * Jean Baptiste Guth (1883–1921), French painter and illustrator * John Guth (born 1981), American poker player * Joseph P. Guth (1860–1928), American architect * Larry Guth (born 1977), mathem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
