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Stilb (unit)
The stilb (sb) is the CGS unit of luminance for objects that are not self-luminous. It is equal to one candela per square centimeter or 104 nits (candelas per square meter). The name was coined by the French physicist André Blondel around 1920. It comes from the Greek word (), meaning 'to glitter'. It was in common use in Europe up to World War I. In North America self-explanatory terms such as candle per square inch and candle per square meter were more common. The unit has since largely been replaced by the SI unit: candela per square meter The candela per square metre (symbol: cd/m2) is the unit of luminance in the International System of Units (SI). The unit is based on the candela, the SI unit of luminous intensity, and the square metre, the SI unit of area. The nit (symbol: nt .... The current national standard for SI in the United States discourages the use of the stilb.IEEE/ASTM SI 10-2002. ''American National Standard for Use of the International System of Units (SI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminance
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 det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candela
The candela (symbol: cd) is the unit of luminous intensity in the International System of Units (SI). It measures luminous power per unit solid angle emitted by a light source in a particular direction. Luminous intensity is analogous to radiant intensity, but instead of simply adding up the contributions of every wavelength of light in the source's spectrum, the contribution of each wavelength is weighted by the luminous efficiency function, the model of the sensitivity of the human eye to different wavelengths, standardized by the CIE and ISO. A common wax candle emits light with a luminous intensity of roughly one candela. If emission in some directions is blocked by an opaque barrier, the emission would still be approximately one candela in the directions that are not obscured. The word ''candela'' is Latin for ''candle''. The old name "candle" is still sometimes used, as in '' foot-candle'' and the modern definition of '' candlepower''. Definition The 26th General C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nit (unit)
NiT, NIT, or Nits may refer to: Education * Namgyal Institute of Tibetology, Sikkim, India * Narula Institute of Technology, West Bengal, India * National Institutes of Technology, India * Naval Institute of Technology, Biliran, Philippines * Nippon Institute of Technology, Japan * Northern Institute of Technology Management, Germany * Babol Noshirvani University of Technology, Iran Science and technology * Nit, the egg case of a head louse * Nit (unit), of luminance * Nat (unit) The natural unit of information (symbol: nat), sometimes also nit or nepit, is a unit of information or information entropy, based on natural logarithms and powers of e (mathematical constant), ''e'', rather than the powers of 2 and binary loga ... or nit, natural unit of information * Network Investigative Technique, computer malware used by the FBI Other uses * National Invitational Tournament (NIT), American college basketball tournament * Nature, Intentions, Time, Special Instructi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
André Blondel
André-Eugène Blondel (28 August 1863 – 15 November 1938) was a French engineer and physicist. He is the inventor of the electromechanical oscillograph and a system of photometric units of measurement. Life Blondel was born in Chaumont, Haute-Marne, France. His father was a magistrate from an old family in the town of Dijon. He was the best student from the town in his year. He went on to attend the École nationale des ponts et chaussées (School of Bridges and Roadways) and graduated first in his class in 1888. He was employed as an engineer by the Lighthouses and Beacons Service until he retired in 1927 as its general first class inspector.See IEEE Industry Applications Magazine May–June 2004 He became a professor of electrotechnology at the School of Bridges and Highways and the School of Mines in Paris.See Hebrew University of Jerusalem Very early in his career he suffered immobility due to a paralysis of his legs, which confined him to his room for 27 years, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candela Per Square Meter
The candela per square metre (symbol: cd/m2) is the unit of luminance in the International System of Units (SI). The unit is based on the candela, the SI unit of luminous intensity, and the square metre, the SI unit of area. The nit (symbol: nt) is a deprecated non-SI name also used for this unit (1 nt = 1 cd/m2). The term ''nit'' is believed to come from the Latin word , "to shine". As a measure of light emitted per unit area, this unit is frequently used to specify the brightness of a display device. The sRGB spec for monitors targets . Typically, monitors calibrated for SDR broadcast or studio color grading should have a brightness of . Most consumer desktop liquid crystal display A liquid-crystal display (LCD) is a flat-panel display or other Electro-optic modulator, electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liq ...s have luminances of 200 to 300 cd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scotopic Stilb
Skot (symbol: sk) is an old and deprecated measurement unit of luminance, used for self-luminous objects (''dark luminance''). The term comes from Greek , meaning "darkness". Overview The skot to measure the dark luminance () was introduced in 1940 by the (, LiTG) out of a necessity to describe the luminance of self-luminous objects, which differed so much from that of other objects that it was impractical to describe it using commonly used luminance values. Conversion factors for so called "scotopic stilb" () depend on the spectral distribution of the light and were therefore redefined in 1948 by the International Commission on Illumination (, IBK) for a specific color temperature of 2042 K or 2046 K, the temperature of solidification of platinum. Before 1948, the definition was based on a temperature of 2360 K as emitted by a wolfram-vacuum lamp. At this temperature, 1 sk = 10−3 asb. The maximum allowed value is 10 skot to avoid the uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Units Of Luminance
Unit may refer to: General measurement * Unit of measurement, a definite magnitude of a physical quantity, defined and adopted by convention or by law **International System of Units (SI), modern form of the metric system **English units, historical units of measurement used in England up to 1824 ** Unit of length Science and technology Physical sciences * Natural unit, a physical unit of measurement * Geological unit or rock unit, a volume of identifiable rock or ice * Astronomical unit, a unit of length roughly between the Earth and the Sun Chemistry and medicine * Equivalent (chemistry), a unit of measurement used in chemistry and biology * Unit, a vessel or section of a chemical plant * Blood unit, a measurement in blood transfusion * Enzyme unit, a measurement of active enzyme in a sample * International unit, a unit of measurement for nutrients and drugs Mathematics * Unit number, the number 1 * Unit, identity element * Unit (ring theory), an element that is i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
