Many of us like to think of photography as an art, separating it as much as possible from the underlying technical elements that actually make all of this stuff work. Of all the complex science that goes into photography, the inverse square law of light is one that’s most often misunderstood. This relatively short video does a solid job explaining this scientific concept and the implications it an have on photography.
The interesting thing about the inverse square law is that it often makes light behave in a way that seems slightly illogical at first glance. For instance, if you’re lighting a small group and the people in the front are noticeably brighter than those in the back, the solution is to move the light backwards (and likely turn up the power a bit) instead of moving it forward to make a bigger light source.
While it might seem a bit like homework and it’s not as much fun as listening to a talk about composition or creative exposures, this is useful information that could come in very handy, especially if you’re getting into off-camera lighting.
From: ISO1200