In 2011, Linco Inc. disclosed two types of technical information regarding fluorescent bulb wattages. The first technical information is about wattage consumption, and the second technical information is about incandescent bulb brightness levels. The calculation provided for incandescent brightness is lumen divided by 14. Customers can download all technical data from the Linco website.
Note: CFLs radiate a different light spectrum from that of incandescent lamps. Improved formulations have improved the subjective color of light emitted by CFLs by such that some sources rate the best 'soft white' CFLs as subjectively similar in color to standard incandescent lamps. Because the eye's sensitivity changes with the wavelength, the output of lamps is commonly measured in lumens, a measure of the power of light perceived by the human eye. The luminous efficacy of lamps refers to the number of lumens produced for each watt of electrical power used. Theoretically, a 100% efficient electric light source producing light only at the wavelength the human eye is most sensitive to would produce 680 lumens per watt. The typical luminous efficacy of CFL lamps is 60 to 72 lumens per watt, and that of normal domestic incandescent lamps is 13 to 18 lm/W. Compared to the theoretical 100% efficient lamp, these figures are equivalent to lighting efficiency ranges of 9 to 11% for CFLs (60/680 and 72/680) and 1.9 to 2.6% for incandescent (13/680 and 18/680).