Light intensity: Why to keep lights as close as possible

oh! here the set up,check out my current threads heres one I have two going


http://boards.cannabis.com/showthread.php?t=86604

damn that 'you must spread rep' box. DAMN IT!!!
After all, you and the Bear are always posting informative stuff.
DAMN DAMN DAMN.
nice one.

Just google 'Inverse Square Law'

The distances are not measured in linear feet, but total area of illumination. distance doubles, light is quartered (same total light, just spread over 4 times the area). A good set of reflective (white foam-core, or mylar covered) panels nearly negate this.

Quote:

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Originally Posted by Splifted

Light intenstiy = Total Light Emitted / ((4 x pi) x (radius^2))

And light intensity decreases by 1/x^2 where x is the distance.

So like if you have 135,000 lumens at 1 foot, you increase that to 2 ft, you it would be 135,000 x 1/2^2 which is 1/4 so basically one fourth of 135,000 = 33,750. Add one more foot, 135,000 x 1/3^2 = 135,000 x 1/9 = 15,000.

Crazy huh? Thats why the top bud always is so big and the bottom ones are smaller, cause they get a lot less light. LST'ing takes that problem away, preventing you from having like 5 feet from the top to the bottom of the plant.

So thats the science behind bigger buds.

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