Definitions for illuminance
ɪˈlu mə nənsil·lu·mi·nance

Princeton's WordNetRate this definition:1.0 / 1 vote

1. illuminance, illuminationnoun

   the luminous flux incident on a unit area

WiktionaryRate this definition:0.0 / 0 votes

1. illuminancenoun

   The luminous flux incident on unit area of a surface; measured in lux or lumens

WikipediaRate this definition:0.0 / 0 votes

1. Illuminance

   In 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. Similarly, luminous emittance is the luminous flux per unit area emitted from a surface. Luminous emittance is also known as luminous exitance.In SI units illuminance is measured in lux (lx), or equivalently in lumens per square metre (lm·m−2). Luminous exitance is measured in lm·m−2 only, not lux. In the CGS system, the unit of illuminance is the phot, which is equal to 10000 lux. The foot-candle is a non-metric unit of illuminance that is used in photography.Illuminance was formerly often called brightness, but this leads to confusion with other uses of the word, such as to mean luminance. "Brightness" should never be used for quantitative description, but only for nonquantitative references to physiological sensations and perceptions of light. The human eye is capable of seeing somewhat more than a 2 trillion-fold range. The presence of white objects is somewhat discernible under starlight, at 5×10−5 lux, while at the bright end, it is possible to read large text at 108 lux, or about 1000 times that of direct sunlight, although this can be very uncomfortable and cause long-lasting afterimages.

FreebaseRate this definition:0.0 / 0 votes

1. Illuminance

   In 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. 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 these are measured in lux or lumens per square metre. In the CGS system, the unit of illuminance is the phot, which is equal to 10,000 lux. The foot-candle is a non-metric unit of illuminance that is used in photography. Illuminance was formerly often called brightness, but this leads to confusion with other uses of the word. "Brightness" should never be used for quantitative description, but only for nonquantitative references to physiological sensations and perceptions of light. The human eye is capable of seeing somewhat more than a 2 trillion-fold range: The presence of white objects is somewhat discernible under starlight, at 5×10^−5 lux, while at the bright end, it is possible to read large text at 108 lux, or about 1,000 times that of direct sunlight, although this can be very uncomfortable and cause long-lasting afterimages.

Matched Categories

1. • Luminosity

How to pronounce illuminance?

1. Alex

   US English

   David

   US English

   Mark

   US English

   Daniel

   British

   Libby

   British

   Mia

   British

   Karen

   Australian

   Hayley

   Australian

   Natasha

   Australian

   Veena

   Indian

   Priya

   Indian

   Neerja

   Indian

   Zira

   US English

   Oliver

   British

   Wendy

   British

   Fred

   US English

   Tessa

   South African

How to say illuminance in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of illuminance in Chaldean Numerology is: 1

2. Pythagorean Numerology

   The numerical value of illuminance in Pythagorean Numerology is: 5

Examples of illuminance in a Sentence

1. Dr. Urooj Umer:

   Live like a star, that always and mesmerize others by its beauty but doesn't anyone by its illuminance and becomes a meteoroid itself...

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