Strobist: Distance & Inverse Square

Following from my last strobist post on direction, now I'm dealing with distance. I didn't have to learn the inverse square rule directly, but I undersand the general idea. Allow Mr. David Hobby to drop knowledge:

Here is what you need to know about the inverse square law: The closer you are to the light source, the more powerful the light. Get real close and it gets really powerful. Get far away, and it gets weaker.

And here's the other thing: The closer you get to the light source, the quicker the lighting values change as you move in. When you get farther away, small differences in distance (from the light) become meaningless.

Also, I must apologize for poor writing and layout. I'm not a "blogging pro", so things may be a bit rough to start.

My first image has the flash at half power and about 8 or 9 feet from the subject. I zoomed the head in a little to about 50mm as well.

Notice how well lit the wall is behind the camera? I can't wait to shoot my Velvia slide, by the way.

Now, the strobe is placed about 5 feet from the subject. The distance is about the same as in the "direction" examples in the first strobist lesson. There's not a lot of difference.

Finally, the strobe is about 1 foot from the subject. I had to crank the power way down (1/32). The wall is (almost) black. The assignment wanted a black wall. I could have moved the table and subject further from the wall, but I understand the concept.

Fun side note: my cheap-o ebay triggers don't fully sync at 1/250 sec. Pocketwizards are moving up the priority list...

The light from the flash definitely develops a shallow "depth of field" as it moves closer to the subject, just like sharpness depth of field. Notice how the "Canon" on my AE-1 is not very well lit even though the flash's beam pattern was pretty wide (27mm).

Knowing how distance changes the depth of light-field (super dorky new term!) gives me some tools when shooting things in the future.