Lux means lumens per squire meter. This means that your 50 foot-candles would equal 0805 watts per square meter. The Relationship Between Lux Lumen And Watt Tachyon Light Per square meter by 93 lumens per watt indicates that bright sunlight provides an illuminance of approximately 98 000 lux lumens per square meter on a perpendicular surface at sea level. How to calculate lux per square meter . While lux is lmm2 a footcandle is lmft2. The distance of 50 meter with 7 meter high pole seems more. The latter is commonly measured in Wm 2 nm 1. An average office may be in the range of 300-500 lux while a family room in a house is down closer to 50 lux and a supermarket up close to 1000 lux. V 2 signifies true airspeed squared which is the square of the speed of the helicopter relative to the oncoming air expressed in meters per second. Measure of light f or plants 400 to 700 nm. In a new environment determining your lux or the lumens per square meter will depend on the ...