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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 ( US, Canada) or torch ( UK, Australia) 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 mid-2000s. A typical flashlight consists of the light source mounted in a reflector, a transparent cover (sometimes combined with a lens) to protect the light source and reflector, a 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 or rechargeable batteries. Some are powered by the user turning a crank, shaking the lamp, or squeezing it. Some have solar panels to recharge the battery. Flashlights are used as a light source outdoors, in places without permanently installed lighting, during power outages, or when a portable light sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychophysics
Psychophysics quantitatively investigates the relationship between physical stimuli and the sensations and perceptions they produce. Psychophysics has been described as "the scientific study of the relation between stimulus and sensation" or, more completely, as "the analysis of perceptual processes by studying the effect on a subject's experience or behaviour of systematically varying the properties of a stimulus along one or more physical dimensions". ''Psychophysics'' also refers to a general class of methods that can be applied to study a perceptual system. Modern applications rely heavily on threshold measurement, ideal observer analysis, and signal detection theory. Psychophysics has widespread and important practical applications. For example, in the study of digital signal processing, psychophysics has informed the development of models and methods of lossy compression. These models explain why humans perceive very little loss of signal quality when audio and video sign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Comfort Probability
Visual comfort probability (VCP), also known as Guth Visual Comfort Probability, is a metric used to rate lighting Lighting or illumination is the deliberate use of light to achieve practical or aesthetic effects. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylig ... scenes. VCP is defined as the percentage of people that will find a certain scene (viewpoint and direction) comfortable with regard to visual glare. It was defined by Sylvester K. Guth in 1963. References Lighting Architectural lighting design Vision {{optics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specular Reflection
Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface. The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by the incident and reflected rays. This behavior was first described by Hero of Alexandria ( AD c. 10–70). Specular reflection may be contrasted with diffuse reflection, in which light is scattered away from the surface in a range of directions. Law of reflection When light encounters a boundary of a material, it is affected by the optical and electronic response functions of the material to electromagnetic waves. Optical processes, which comprise reflection and refraction, are expressed by the difference of the refractive index on both sides of the boundary, whereas reflectance and absorption are the real and imaginary parts of the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Over-illumination
Overillumination is the presence of lighting intensity higher than that which is appropriate for a specific activity. Overillumination was commonly ignored between 1950 and 1995, especially in office and retail environments.M.D. Simpson, ''A flexible approach to lighting design'', Proc. CIBSE National Lighting Conference, Cambridge, 8–11 April 1990, 182-189, Chartered Institution of Building Services Engineers Since then, however, the interior design community has begun to reconsider this practice. Overillumination encompasses two separate concerns: * Unnecessary electric lighting is expensive and energy-intensive. Lighting accounts for approximately 9% of residential electricity use and about 40% of commercial electricity use. * Excessive levels of artificial light may adversely affect health. These detrimental effects may depend on the spectrum as well as the overall brightness level of light. Overillumination can be reduced by installing occupancy sensors, using natural su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyot Stop
A Lyot stop (also called a glare stop) is an optical aperture, stop, invented by French astronomer Bernard Lyot, that reduces the amount of Lens flare, 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 References External linksNASA Coronagraphs by Bass et al. Optical devices Photography equipment {{Optics-stub ... [...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 aperture made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afterimage
AfterImage is a Filipino rock band formed in 1986, best known for their songs "Habang May Buhay", "Next in Line", and "Mangarap Ka". They disbanded in 1997 and became active again in 2008 after they reunited and released their fourth studio album. After disbanding in 1997, Wency Cornejo, the band's vocalist, pursued a solo career. In January 1992, the band signed with Dyna Records, The band's first album, entitled ''Touch the Sun'', was released in July 1992. Among the eight songs that the album contained, four were released as singles: "Next in Line", "Bai (Sa Langit ang Ating Tagpuan)", "Only You", and "Pagtawid". The title of the album, which was the concluding part of the lyric to "Next in Line", was said to have just been a spontaneous utter of phrase which Cornejo made during the recording session for the said song. History The band was composed of five members: Bobit Uson on bass guitar, Chuck Isidro on lead guitar, Rogie Callejo on drums, Arnold Cabalza on keyboards and ... [...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 * 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 * Eugene Guth (1905–1990), Hungarian-American physicist * 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), mathematician * Louis D. Guth (1857–1939), American businessman and politician * Paul Guth (1910–1997), French humorist and writer * Raymond Guth (1924–2017), American film and television actor * William West ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Logarithm
In mathematics, the common logarithm is the logarithm with base 10. It is also known as the decadic logarithm and as the decimal logarithm, named after its base, or Briggsian logarithm, after Henry Briggs, an English mathematician who pioneered its use, as well as standard logarithm. Historically, it was known as ''logarithmus decimalis'' or ''logarithmus decadis''. It is indicated by , , or sometimes with a capital (however, this notation is ambiguous, since it can also mean the complex natural logarithmic multi-valued function). On calculators, it is printed as "log", but mathematicians usually mean natural logarithm (logarithm with base e ≈ 2.71828) rather than common logarithm when they write "log". To mitigate this ambiguity, the ISO 80000 specification recommends that should be written , and should be . Before the early 1970s, handheld electronic calculators were not available, and mechanical calculators capable of multiplication were bulky, expensive and not widely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Illumination
The International Commission on Illumination (usually abbreviated CIE for its French name, Commission internationale de l'éclairage) is the international authority on light, illumination, colour, and colour spaces. It was established in 1913 as a successor to the Commission Internationale de Photométrie, which was founded in 1900, and is today based in Vienna, Austria. Organization The CIE has six active divisions, each of which establishes technical committees to carry out its program: * Division 1: Vision and Colour * Division 2: Physical Measurement of Light and Radiation * Division 3: Interior Environment and Lighting Design * Division 4: Transportation and Exterior Applications * Division 6: Photobiology and Photochemistry * Division 8: Image Technology Two divisions are no longer active: * Division 5: Exterior Lighting and Other Applications * Division 7: General Aspects of Lighting The President of the CIE from 2019 is Dr Peter Blattner from Switzerland. CIE publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid Angle
In geometry, a solid angle (symbol: ) is a measure of the amount of the field of view from some particular point that a given object covers. That is, it is a measure of how large the object appears to an observer looking from that point. The point from which the object is viewed is called the ''apex'' of the solid angle, and the object is said to '' subtend'' its solid angle at that point. In the International System of Units (SI), a solid angle is expressed in a dimensionless unit called a ''steradian'' (symbol: sr). One steradian corresponds to one unit of area on the unit sphere surrounding the apex, so an object that blocks all rays from the apex would cover a number of steradians equal to the total surface area of the unit sphere, 4\pi. Solid angles can also be measured in squares of angular measures such as degrees, minutes, and seconds. A small object nearby may subtend the same solid angle as a larger object farther away. For example, although the Moon is much smaller ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
