Light intensity: Why to keep lights as close as possible

[Splifted]

The thing is if I begin that equation at 2", wouldn't I arrive at a more rapidly diminishing variable? I was always lousy at math though imp:

Yeah, you would, but at 2" it would be a lot brighter than at 1 foot, and at 4" it should be half as bright as it was at 2". I think. You also have to take into account that light isn't projected in a square, either, but that is the basics.

Haha, its been like 2 years since I took AP physics.


Here it is a little more in depth if you were wondering

http://www.ifa.hawaii.edu/~barnes/AS...rsesquare.html