HID to LED Wattage Cross Reference
* Scotopic refers to visual perception in low light. Photopic refers to colour perception in normal light. The ratio of Scotopic light vs Photopic light is called S/P ratio. This ratio determines the apparent visual brightness of a light source. Higher S/P ratios appear brighter to the human eye. See: “Energy Efficiency Consequences of Scotopic Sensitivity”, Dr. Sam Berman, Journal of the IES, Vol 21 No.1, Dec. 1992 “The Coming Revolution in Lighting Practice”, Dr. Sam Berman, http://www.lightenergysource.com/ScotopicTechnical.htm
**Scotopic/Photopic ratios used: MH/PSMH = 1.49, HPS = 0.62, LED (6500K) = 2.14. HID fixtures assumed to be 70% optically efficient, actual efficiency will vary. Mean lumens of 95% used for LED. The HI Lighting Calculator is provided to assist users in making lighting decisions based on various assumptions, factors and methods. Efforts have been made to ensure accurate assumptions in development of this table, however, iQ LIGHTING does not warrant or guarantee, either express or implied, that the results obtained herein will be obtainable under actual use conditions. iQ Lighting is not responsible for any loss resulting from the use of this table.