does lumens add up?

hi all, i would like to know if lumens add up?...i was told they dont..

See up there at the top of your screen where there is a sticky thread that says lumens, lux, and adding it all up?

Look there.

everyone says it goes like one over distance squared, like gravity. Makes sense cause light goes out in all directions. It would be sort of like (L1/(r1^2))+(L2/(r2^2)) for light one with L1 lumens and light 2 with L2 lumens. Kinda complicated, but not that bad. Anyways, more lights is still more lumens, and you can measure with a light meter.

thanks for the info

thesmokering said:

everyone says it goes like one over distance squared, like gravity. Makes sense cause light goes out in all directions. It would be sort of like (L1/(r1^2))+(L2/(r2^2)) for light one with L1 lumens and light 2 with L2 lumens. Kinda complicated, but not that bad. Anyways, more lights is still more lumens, and you can measure with a light meter.

Click to expand...

I dont know what any of that really means but I can tell you more light intensity equals more lumens.A good example is a 400wHPS and CFLs. A 400wHPS bulb puts out about 50,000 lumens. Four 100watt CFLs put out around 6400 lumens. both 400watts but no comparison in lumens. That why you yield more quality bud with HIDs.

"What this means is that if you put two lights the same distance from a point, and each light provides N photons per unit area at the point, with two lights you will have 2N photons per unit area at the point. Because intensity is a measure of the number of photons per unit area, the light is twice as intense, whatever unit you choose to use. Twice the lumens, twice the lux, twice the footcandles."

straight out of the sticky

Im just concerned with the overall quality of the buds. All the tech stuff is cool but most of us need it in plain english. Two lights cover more area and can be put closer to the plants which increases photosynthesis and light penetration and produce higher yields and higher quality buds. Basically! Thanks for the lesson though.