When you do the light meter test, make sure you are not checking for lumens, since that's only what the human eye sees. You want to check for radiant flux instead of luminous flux, since that is the real amount of light.
Opie Yutts Reviewed by Opie Yutts on . CFL Light Intensity Question... Does anyone know the optimum positioning of a CFL. What I mean is, does a CFL's light intensity radiate parallel to the bulb (inline with the coil) or perpendicular to the coil. I don't know exactly how to explain my question, but I do not know if I should align my bulbs so that they point at my plants, downward vertically, or if they should be aligned so that they point outward, horizontally. Does anyone know ? Rating: 5