Lighting 102: Restriction
Restricting light is a powerful control. By taking light away, we can evoke character or drama or mystery or any number of other things. My friend Joe McNally goes as far as to distill it down to this:
"If you want to make something more interesting, don't light all of it."
He's absolutely right. And there are lots of ways to make your light more interesting by merely taking something away. In the photo above, for instance, I am restricting the light from my umbrella from reaching the top of Dean's head.
It wasn't hard to do. My umbrella is pretty much right over the top of the camera. Maybe a little to the right. Between the umbrella and Dean, I placed a piece of poster board (clamped it to a light stand) to partially block the light. This allowed the light to reach his face, but not the top of his head.
This is called a "flag," or "flagging" the light. Because a piece of rectangular cardboard clamped to a light stand is literally the shape of a flag on a pole.
In doing this, I went from straight umbrella light to something more evocative. Instead of being fully awash in light, Dean is now transitioning into an area of light. Not unlike when someone walks through a door into a room with brighter light and for a brief moment they are halfway into the new light. And that always looks cool.
You've noticed that, right? Maybe you have even placed someone in a doorway to exploit that transitional light for a portrait.
Well, with light—and something to partially block it—you can easily make those visual moments. Restrict your light to make it more interesting.
In the photo above, I should say that there is a second bare flash putting a small amount of light onto the background. Otherwise it would be flagged and dark, right? And that light is also spilling a little bit onto the back camera right side of Dean's head.
Controlling the Transition Area of a Flag
Okay, it is pretty obvious that you would move the flag up or down to raise or lower the transition zone, right? But there is another variable to control, too.
The softness of the transition zone (between flagged and not flagged) is controlled by two things. The first is the softness of the light source (remember: how big and/or close it is to the subject). The second is how close you place the flag to the subject versus the light source.
As any kid who has ever made shadow animals on a wall knows, the closer your hand is to the wall—and/or the harder the light source—the sharper the shadow animal. And vice versa. See? You really already know this stuff. It's intuitive. You know it just by having been alive and watching light in the world. I'm just here to remind you of stuff you already know.
We can also restrict light with a snoot (tube) on a flash. Or a grid spot (remember the face light for our pearl-bedazzled bride a few posts back?) You can also do it by adjusting the beam of your flash, to 85mm or 105mm for instance.
Next: One More Thing
New to Strobist? Start here | Or jump right to Lighting 101
Connect w/Strobist readers via: Words | Photos
Got a question? Hit me on Twitter: @Strobist
Save Money: Browse MPEX Weekly Strobist Deals