In USMA 18797 I wrote; >555 nm is the wavelength to which the human eye is most sensitve. > >The 16th CGPM (1979, Resolution 3): >"The candela is the luminous intensity, in a given direction, of a source >that emits monochromatic radiation of frequency 540 x 10^12 hertz and that >has a radiant intensity in that direction of 1/683 watt per steradian."
I had not noticed that 555 nm and 540 x 10^12 hertz are equivalent statements. On page 149 of the metric bible I found the following: "radiation at 540 x 10^12 Hz which corresdponds to a wavelength of 555.016 nm in standard air." Joseph B.Reid 17 Glebe Road West Toronto M5P 1C8 TEL. 416-486-6071
