Lighting a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm). The SI unit of illuminance and luminous emittance, being the luminous power per area, is measured in Lux. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes
Transverse measure Transverse measure In mathematics, a measure on a real vector space is said to be transverse to a given set if it assigns measure zero to every translate of that set, while assigning finite and positive (i.e. non-zero) measure to some compact set. Let "V" be a real vector space together with a metric space structure with respect to which it is a complete space. A Borel measure "μ" is said to be transverse to a Borel-measurable subset "S" of "V" if The first requirement ensures that, for example, the trivial measure is not considered to be a transverse measure.