For consistent white background illumination, place two lights behind a subject on each side of the frame. This ensures even lighting without hotspots.
One of the most popular requests I get from portrait clients is to photograph them in front of a white background. It’s for good reason, too. The look has a timeless quality, plus it’s clean and simple.
White background portraits can also be easily clipped and dropped into other scenes as needed. And while the look is simple and doesn’t require much specialized equipment, getting it just right takes some know-how.
How can photographing someone on a white background be difficult? If you simply put a person in front of a white wall, won’t you get a white background by default?
Actually, no. When you photograph someone in front of a white background without proper illumination, the white background turns from white to light gray.
In response, photographers too often crank up the background light and overpower the background, forcing it and everything in the vicinity to turn bright white. The issue is that this approach too often causes lens flare and impacts the subject in unappealing ways. At best, it makes your subject’s edges undefined and blurry. At worst, light spills onto them and creates ugly lighting and disastrous loss of detail.
To avoid these pitfalls, here are a few techniques to ensure white backgrounds remain nice and bright and the subject looks their best.
Method #1: One Light With Subject Positioned Near The Background
This approach is different from the typical light-background look because it doesn’t rely on a background light. In fact, it can be achieved with just one light placed fairly far from the subject—so long as the subject stands close to the background.
This do-it-all keylight works to light the subject and keep a bright background bright because of the “depth of light” principle: Because light falls off in intensity as it travels farther from the source, the distance from the subject to the background greatly impacts the luminosity of the background:
- So, if the subject is far from the background, the light falls off as it travels past the subject and on to the background.
- But if the subject is close to the background, the light doesn’t have the opportunity to fall off as much.
This effect is amplified as the keylight is moved farther from the subject because it requires even more distance from subject to background for any falloff to be visible.
Take a look at the three examples from the first two pages of this story: The keylight is placed 16 feet from the background. In each of the three shots, the subject is positioned 4 feet, then 8 feet and finally 12 feet from the background.
The exposure is adjusted to compensate for the subject’s position relative to the keylight, but the output of the light is not altered. You can see how, with the light’s position unchanged relative to the background, cycling through apertures from ƒ/2.8 to ƒ/4 and ƒ/5.6 to keep the subject correctly exposed would alter the brightness of the background.
If you want to keep the background as bright as possible without using a second light, place the subject close to the background and the keylight far away. This approach is simple and effective, though it doesn’t provide quite the control of lighting the background independent from the subject.
For that, you’ll need a dedicated background light.
Method #2: Two Lights With Distance Between The Subject And Background
The ideal way to ensure a white background looks white is to put some distance between subject and background and light the two independently. The distance is necessary to ensure that one light (the background light, in particular) does not spill over and impact the other.
The distance between subject and background determines the correct amount of overexposure necessary to render the white background truly white.
Put simply, to make a white background appear bright white in pictures, it has to be slightly overexposed relative to the subject. But, too much overexposure makes the background light blow out and affect the subject, blurring his or her edges and causing flare that saps contrast and sharpness.
The process begins by metering the lights independently. This is easiest to accomplish with a handheld light meter, though it can be done with just a camera. By turning lights off to make independent test shots, you can establish the same exposure information for subject and background by checking the results on the back of the camera.
If the keylight meters ƒ/5.6 at the subject, the background should meter brighter than that—ideally f/8 or even more. If it meters at ƒ/5.6, the background will likely appear off white, or even gray, in the picture.
The farther the subject is from the background, the less likely the chances for spill, so the brighter the background can be. For years, I’ve used the following guidelines as a rule of thumb:
- With the subject 8 feet from the background, overexpose by one stop.
- With the subject 12 feet from the background—which is ideal—overexpose by 1.5 stops.
- Any brighter than that, and it won’t appear any brighter, but lens flare becomes a greater risk.
This rule originated in the film era, when it was even trickier to get a white background bright white in camera. Add to that the fact that there is greater leeway with digital capture, and this task should be easier than ever. That said, the principle holds true: You’ve got to overexpose a white background to make it pure white, and the closer the subject is to the background, the less you can overexpose.
Bring It All Together
The above principles form the basic premise needed to achieve bright-white portrait backgrounds, but, of course, the devil is in the details. Here are the essential tips and tricks that bring it all together in practice:
- Use two soft lights: Ideally you want the background to be evenly illuminated across the frame. Do this by diffusing the light sources with umbrellas or softboxes, and using two lights placed on either side of the scene. (See the example shown page 24, where an umbrella is placed behind and on each side of the subject.) To further avoid hot spots and ensure the background is as even as possible, don’t aim the lights directly at the center of the background. Instead, aim them at opposite sides of the background—the right light pointed at the left edge of the background and vice versa. With a light meter in hand, meter each corner of the background as well as the center to ensure all are within one-third of a stop from each other, repositioning the lights as needed.
- Light in layers: Rather than turning on all of the lights and trying to fine-tune them together, my preferred method for any portrait lighting situation—especially white backgrounds—is to get each light positioned and powered up correctly one by one. This holds true whether I’m lighting with hot lights, strobes or LEDs, or even if I’m using daylight modified by scrims, flags and reflectors. By lighting each element independently, I can ensure I see exactly what a given source is doing. In this way, I can better control all the nuances of the lighting in the scene.
For white backgrounds, I start by turning on the background lights and establishing their evenness and exposure before turning on the keylight. I like to ensure I’ve got a good silhouette going, with the subject having well-defined edges and the background appearing evenly and brightly illuminated. Then I’m ready to turn off the background lights and work solely on the keylight. If I’ve established the background light is already at ƒ/8, I know I’ll likely need the keylight to meter approximately ƒ/5.6 to ensure the background is sufficiently overexposed. I can then set the exposure appropriately (to ƒ/5.6) and then reposition and adjust the output of the keylight until it matches the predetermined setting. Finally, I can turn on both the background lights and the keylight to check that they do, in fact, work together as expected.
- Prevent spill: With the subject and background separately illuminated according to the guidelines above, you might think the process is complete. But, in fact, there’s a crucial step to ensure the lights remain in isolation, and that’s called flagging the background lights. While any light from the key source spilling onto the white background isn’t a big deal, the reverse is not true. If background lights accidentally illuminate the subject, they can create unattractive hot spots, shadows or, worst of all, dramatic overexposure and loss of detail.
See the example above for evidence of ugly overexposure caused by spill from background lights. To remedy this, flags are positioned between the background lights and the subject. Movie productions use fabric flags on metal frames held in place by c-stands, but really any black or opaque object will do so long as it can prevent the background lights from spilling onto the subject.
My favorite flag is a large 4-x-8 sheet of foamcore. These can be positioned easily between subject and background lights to prevent spill. A white foamcore flat opposite the keylight can also be used as an efficient reflector.
4. Define the edges: When photographing a subject on a white background, it helps to create definition by positioning the keylight to create shadows that define the subject’s shape. If the subject has light hair and skin and wears white- or light-colored clothing, they will blend in with a bright background more easily. To help define the subject against the bright background no matter what they’re wearing, place black flags or v-flats on either side of the subject, as close as possible but just out of frame. This creates what’s known as negative fill, which provides better edge definition in order to keep the subject from blending into the background. The flags that prevent background light spill can often be positioned to do double duty as negative fill as well. It’s for this same edge-definition quality that it’s rarely a good idea to use a hair light or edge light when photographing someone on a white background, as brightness at their edges further blends the subject with the background rather than helping them to stand out.