 I put this 60 watt bulb here and this 60 watt bulb is producing 865 lumens of light. When I hold this bulb very close to this surface area here where the light is being measured, all this 800 is falling on a small area. Obviously if we try to measure the lumens that are falling on the small area or number of lumens per square foot is very, very high. As you can see roughly there we have about 1200 lumens per square foot, very highly concentrated. As I move this bulb away the value goes down because the same number of lumens are being distributed over larger area as you can see here. Now it's about 100 lumens and if I go further up it's going to reduce.