Light types of unit Illuminance Converterlux, meter-candle, centimeter-candle, foot-candle, phot, nox, candela steradian/meter², lumen/meter², lumen/centimeter², lumen/foot², watt/centimeter² (at 555 nm) Frequency and Wavelength Converterhertz, exahertz, petahertz, terahertz, gigahertz, kilohertz, hectohertz, dekahertz, decihertz, millihertz, microhertz, nanohertz, picohertz, femtohertz, attohertz, cycle/second