Electromagnetic energy flux, the amount of energy traveling at some point x in a specified direction , per unit time per unit area perpendicular to the direction per unit solid angle for a specified wavelength denoted by
A measure of the energy radiated by the object together with the frequency distribution of that radiation
The radiation passing through a point in a specific direction, expressed in SI units of watts per steradian per square meter In the Radiance system, only visible radiation is considered, but units of radiance and irradiance are still used, which are divided into separate components for the red, green, and blue spectral ranges (Compare to luminance )
Brightness; the radiant energy per unit solid angle and per unit projected area of a radiating surface
Radiance is a measure of radiometric flux density per unit solid angle Radiance is typically expressed in W/cm2/sr (watts per square centimeter per steradian)
the quality of being bright and sending out rays of light the amount of electromagnetic radiation leaving or arriving at a point on a surface an attractive combination of good health and happiness; "the radiance of her countenance
A measure of the amount of electromagnetic radiation leaving a point on the surface More precisely, it is the rate at which light energy is emitted in a particular direction per unit of projected surface area The projected surface area is the projection of the surface onto the plane perpendicular to the direction of radiation It is found by multiplying the surface area by , where is the angle of the radiated light to the surface normal
The quality of being radiant; brilliancy; effulgence; vivid brightness; as, the radiance of the sun
Measure of the energy radiated by an object In general, radiance is a function of viewing angle and spectral wavelength and is expressed as energy per solid angle
The radiation energy per unit time coming from a specific direction and passing through a unit area perpendicular to the direction