Two-Light Night, Part 1: Backlight Versus Background Light

Holly's dark hair against a black background. The backlight separates, but when the light is too hot, it also distracts and exaggerates the frizz factor.

I tested several variables at last Thursday’s practice session. Using the same black background and a single lens, I shot all four models using two lights in different configurations.

For the key light, I tried a bounce umbrella, a shoot-through umbrella, and a Gary Fong Lightsphere – the Lightsphere both on and off the camera.

But I’ll write about that later, because today’s post is about the second light and the black background.

In my theater publicity work, I often get to choose between two backgrounds: a black wall or a black curtain. If I get a blonde or silver-haired subject in light colored clothes, no problem. But most of the time, I must use one of my lights to separate the dark-haired, darkly dressed subject from the dark background.

There are a lot of lighting techniques you can use to achieve this separation, especially if you have a boom stand or a convenient low, white ceiling in your camera bag. I don’t. I carry two flash units and two basic stands, a couple of umbrellas, some gels and a foldable reflector.

I use one flash and the reflector for key light and fill, so the second flash becomes either a backlight or a background light.  In other words, I either point it at the back of the subject or I point it at the background. Each choice offers pros and cons, as described in the captions.

In this case, turning the light toward the background turned black grey. It also revealed every crease and wrinkle in the fabric, and I assure you there were many. It took a lot of computer time to smooth things out. Kara's daughter saw this picture and told her she forgot to button her shirt.

A bit of a two-fer on this shot of Brook, because I put a diffuser on the rear flash. That's why it's acting as both a backlight AND a background light. Strong backlight can be a beautiful effect, but it will also reveal every individual bit of peach fuzz on a model's neck. And remember that the viewer's eye will be attracted to the brightest part of the image, for better or worse.

I don't carry a white ceiling to the theater, but I have one at home, where I shot these. In this case, I didn't use a backlight or background light. Instead, I replaced my key light umbrella with the Gary Fong Lightsphere, which bounces light in all directions. Light bouncing off the ceiling lit the top of Jaye's head to help separate her from the background.

The ceiling bounce works on dark hair too, offering just a kiss of light to keep Holly's head from melting into the background. This way, we get a nice dark background, a softly lit subject, and a bit of separation between the two.

Next time: Can you use a Gary Fong Lightsphere instead of an umbrella? (Actually, you can use a piece of paper or a fat guy in a white t-shirt instead of an umbrella, so we’ll really just talk about quality and control of the light using different kinds of diffusers)

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Filed under Dance and Theater, Lighting, Portraiture, Post Processing

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