Photographer Chris Grey is an expert on lighting. He's written seven books on the subject, teaches classes and workshops, and is a strong advocate for precise control in the studio. To see more of his work, or to find his books and DVDs, visit his Web site.
Just as you should vary the look of your key and hair lights with softboxes, gridspots, or other modifiers, you should do the same with the background light. Many photographers settle in to a lighting routine, especially with their background light. After all, its only purpose is to add dimension to the image, so why spend additional time fiddling with it?
Think of each light modifier as a “personality.” Strong or weak, hard or soft, each modifier is a tool to help you shape your subject into what you see in your mind’s eye.
I’ve written many times about how valuable white foamcore panels are as gobos or reflectors. Here’s a simple technique to create a background light modifier from a sheet of foamcore that will baffle both clients and peers. It’s got low price going for it, too, which is nice.
I began by setting my key light, a large softbox in this case, about four feet from my subject. I was working in close quarters for this shot, and didn’t have the luxury of a wide-open space. Also, I wanted a soft, wrap-around light that would fall off quickly as it crossed the planes of my model’s face and body.
The key itself was less than six feet from the background, which, because of that short distance, would photograph more brightly than I wished. To cut that light, I moved a black foamcore bookend to block about half the key’s output from reaching the background wall.
Here’s the trick: I balanced a 4’x8’ sheet of foamcore against an Avenger accessory arm directly behind where my model would be standing. The sheet was butted up perpendicular to the wall and as close to it as possible.
To light the background, I used a beauty bowl with a 25-degree gridspot, although most any reflector and grid will do if the light it throws suits your vision. I aimed the light directly at the point where the foamcore met the wall, and from a high angle. The foamcore kept the background light from spreading across the back of the set.
I knew that the top of the 4’x8’ foamcore would be seen behind the model, so I planned in advance to crop slightly into the top of the image, to hide the gobo. It’s important to pay attention to how your model is moving because the gobo needs to be held at the very top of the subject. If it isn’t, you may be forced to crop more deeply than you’d like.
I used a 4’x8’ panel because I keep several around in case I need another bookend. Foamcore is also available in 4’ and 5’ lengths (with a 4’ depth), lengths that are easier to find in many markets and which work just as well. Even better, actually, if you wish to include airspace above the models head. They are easy to rig, too. Just clamp the sheet to a light stand, as high as possible behind the model. Another clamp placed lower on the stand will help keep the sheet vertical. Use the model’s body to block the stand and gobo.
The thinnest part of a model’s body is the neck, and this can present a visual problem if you want a tilted head. If you have room, place the model several feet further in front of the gobo. Such positioning makes the model much wider, visually, than the gobo. Your model is now able to make more exaggerated movements without giving away the trick.