. . "http://en.wikipedia.org/wiki/Illuminance"^^ . . . "Luminous Flux per Area"@en . "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. In SI derived units these are measured in \\(lux (lx)\\) or \\(lumens per square metre\\) (\\(cd \\cdot m^{-2}\\)). 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."^^ . . .