44 relations: Adaptation (eye), Black body, Candle, Candlepower, Coherence (physics), Foot-candle, General Conference on Weights and Measures, Grain (unit), Green, Hefner lamp, Human eye, Illuminance, International Commission on Illumination, International System of Units, Jules Violle, Latin, Light, Light meter, Light-emitting diode, Lumen (unit), Luminosity function, Luminous flux, Luminous intensity, Multifaceted reflector, National Institute of Standards and Technology, Normal (geometry), Operational definition, Photopic vision, Planck's law, Platinum, Proposed redefinition of SI base units, Radiant intensity, Radiometry, Scotopic vision, Second, SI base unit, Solid angle, Spectrum, Spermaceti, Square metre, Steradian, Watt, Wavelength, Weighting.
In ocular physiology, adaptation is the ability of the eye to adjust to various levels of light.
A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence.
A candle is an ignitable wick embedded in wax, or another flammable solid substance such as tallow, that provides light, and in some cases, a fragrance.
Candlepower (abbreviated as cp or CP) is an obsolete unit expressing luminous intensity, equal to 0.981 candelas.
In physics, two wave sources are perfectly coherent if they have a constant phase difference and the same frequency, and the same waveform.
A foot-candle (sometimes foot candle; abbreviated fc, lm/ft2, or sometimes ft-c) is a non-SI unit of illuminance or light intensity.
The General Conference on Weights and Measures (Conférence générale des poids et mesures – CGPM) is the supreme authority of the International Bureau of Weights and Measures (Bureau international des poids et mesures – BIPM), the inter-governmental organization established in 1875 under the terms of the Metre Convention (Convention du Mètre) through which Member States act together on matters related to measurement science and measurement standards.
A grain is a unit of measurement of mass, and in the troy weight, avoirdupois, and Apothecaries' system, equal to exactly.
Green is the color between blue and yellow on the visible spectrum.
The Hefner lamp, or in German Hefnerkerze, is a flame lamp used in photometry that burns amyl acetate.
The human eye is an organ which reacts to light and pressure.
In photometry, illuminance is the total luminous flux incident on a surface, per unit area.
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.
The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system, and is the most widely used system of measurement.
Jules Louis Gabriel Violle (16 November 1841, Langres, Haute-Marne – 12 September 1923, Fixin, Bourgogne-Franche-Comté) was a French physicist and inventor.
Latin (Latin: lingua latīna) is a classical language belonging to the Italic branch of the Indo-European languages.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
A light meter is a device used to measure the amount of light.
A light-emitting diode (LED) is a two-lead semiconductor light source.
The lumen (symbol: lm) is the SI derived unit of luminous flux, a measure of the total quantity of visible light emitted by a source.
A luminosity function or luminous efficiency function describes the average spectral sensitivity of human visual perception of brightness.
In photometry, luminous flux or luminous power is the measure of the perceived power of light.
In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye.
A multifaceted reflector (often abbreviated MR) light bulb is a reflector housing format for halogen as well as some LED and fluorescent lamps.
The National Institute of Standards and Technology (NIST) is one of the oldest physical science laboratories in the United States.
In geometry, a normal is an object such as a line or vector that is perpendicular to a given object.
An operational definition is the articulation of operationalization (or statement of procedures) used in defining the terms of a process (or set of validation tests) needed to determine the nature of an item or phenomenon (a variable, term, or object) and its properties such as duration, quantity, extension in space, chemical composition, etc.
Photopic vision is the vision of the eye under well-lit conditions (luminance level 10 to 108 cd/m2).
Planck's law describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T. The law is named after Max Planck, who proposed it in 1900.
Platinum is a chemical element with symbol Pt and atomic number 78.
The International Committee for Weights and Measures (CIPM) has proposed revised definitions of the SI base units, for consideration at the 26th General Conference on Weights and Measures (CGPM).
In radiometry, radiant intensity is the radiant flux emitted, reflected, transmitted or received, per unit solid angle, and spectral intensity is the radiant intensity per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength.
Radiometry is a set of techniques for measuring electromagnetic radiation, including visible light.
Scotopic vision is the vision of the eye under low-light levels.
The second is the SI base unit of time, commonly understood and historically defined as 1/86,400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each.
The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived.
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.
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum.
Spermaceti (from Greek sperma meaning "seed", and ceti, the genitive form of "whale") is a waxy substance found in the head cavities of the sperm whale (and, in smaller quantities, in the oils of other whales).
The square metre (International spelling as used by the International Bureau of Weights and Measures) or square meter (American spelling) is the SI derived unit of area, with symbol m2 (Unicode character). It is the area of a square whose sides measure exactly one metre.
The watt (symbol: W) is a unit of power.
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
The process of weighting involves emphasizing the contribution of some aspects of a phenomenon (or of a set of data) to a final effect or result, giving them more weight in the analysis.