Luminous emittance

Descriptive image of the illuminance.

In photometry, the Luminous emitting (M{displaystyle scriptstyle {M}}), or luminous success is the amount of luminous flux that emits an area per unit, while, enlightenment (E{displaystyle scriptstyle {E}}) is the amount of luminous flux that incites on a surface per unit area. The unit of measurement of both luminous and illuminance in the International System is the lux: 1 lux = 1 lumen/m2.

Definitions

Luminous emittance

In general terms, the luminous emittance is defined according to the following expression:

MV=dFdS{displaystyle M_{V}={frac {dF}{dS}}}}}

where:

• M_V is the emission, measured in lux.
• F is the luminous flux emitted, in lumens.
• dS is the differential element of emission area considered, in square meters.

Luminous emittance can be defined from the radiometric magnitude of radiant emittance simply by weighting each wavelength by the sensitivity curve of the eye.

Illuminance

In general terms, illuminance is defined according to the following expression:

EV=dFdS{displaystyle E_{V}={frac {dF}{dS}}}}}

where:

• E_V is the illuminance, measured in lux.
• F is the luminous flux incident, in lumens.
• dS is the differential element of area of incidence considered, in square meters.

The illuminance can be defined from the radiometric magnitude of the irradianity but to ponder each wavelength by the sensitivity curve of the eye. Yeah. EV{displaystyle scriptstyle {E_{V}}}}It's the illuminance, Eλ λ {displaystyle scriptstyle {E_{lambda }}}} depicts spectral irradiance and V(λ λ ){displaystyle V(lambda)} symbolizes the sensitivity curve of the eye, then:

EV=K∫ ∫ visibleE(λ λ )V(λ λ )dλ λ {displaystyle E_{V}=Kint _{visible}^{ }E(lambda)V(lambda),dlambda }

Both illuminance and lighting level can be measured with a device called a photometer. The illuminance that emits a surface per unit area is called a luminous emission (MV{displaystyle scriptstyle {M_{V}}}}).