Quote Originally Posted by noodlesqld
just a quick question i have a few 15w cfl's that have a rating of 6500k lumens and i was wondering what equation you are using to get this figure is it, 6500k divided by 15 watts, as for me this workes out to 433.33 lumens per watt or do you use the full wattage i.e 15w =75w output, such as 6500k divided by 75 watts= which equal about 86.6 lumens per watt
no...your taking the color temp dividing the wattage...what you need to do is take the lumens and divide it by the wattage....2000lumens/30watts=66 something lumens per watt