Rangefinder Magazine
Features

Unraveling the Mysteries. . .by Stephen Dantzig, Psy. D

One of the most challenging techniques in photography is photographing white garments against a white backdrop. However, white on white photography has become one of my favorite techniques. I love the look of a clean white backdrop while maintaining beautiful detail in the wardrobe. In fact, as a commercial photographer, my job is show every detail of the wardrobe, light the model beautifully and provide a clean area for my client to drop in text. While it is true that the advances in digital programs such as Photoshop make the latter part easy in post-production, it is still much better to get it on film.

The most difficult part of shooting against a white backdrop is controlling flare. Flare presents a problem regardless of the color of the wardrobe. However, it is particularly easy to lose the detail in the edges of the wardrobe when it is white. Flare, in its simplest terms, is the result of too much light entering the lens from behind, or from the sides of your subject. The risk of flare from sidelights can be effectively eliminated by the use of “flags” and a good lens shade.

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However, by throwing light onto a white backdrop, we have just created a 9x20-foot light source with its light aimed directly at your camera lens! It is difficult to flag the light coming from directly behind your subject, so we now have light falling on our subject from the front and the back. To make matters even more complicated, the backlight, or the light hitting the backdrop needs to be a full stop brighter [on most popular transparency films] than the working aperture in order to ensure a white-without-detail backdrop. In most of my photography, the light hitting the backdrop will also be one-half to eight-tenths of a stop brighter than the lights illuminating the front of my model. We have just created the exact situation that we wanted to avoid.

Fortunately, the solution is fairly simple. Remember the inverse square law when positioning your model in relation to your lights. Light falls off by the square of the distance. For example, take a light source that is positioned 2 feet from a board with one-inch square grids. For argument’s sake, say the light source covers 4 square inches and produces an exposure of X. If the light is moved back 2 feet it will now cover 16 square inches and will produce an exposure of 1/4X. The light was moved two feet and the inverse square law states that light will fall off at a rate of 1/distance squared. In this case, the change in distance is 2 feet, so the change in exposure is 1/2 squared, or 1/4. Position your model far enough away from the backdrop so the light hitting her from the backdrop measures less than your working aperture.

The understanding of, and use of your light meter is critical in making this technique work. My meter is on incident mode for all of my studio work. The incident mode reads the light that falls on the meter and records light in relation to 18% gray—or middle gray. Everything else in the scene falls into its proper zone. However, I will meter the light falling onto my subject differently depending upon what part of the scene a particular light is illuminating. Lights fall into two categories: front lights and non-front lights. ANY light that illuminates the front of ANY part of my set is considered a front light. Front lights include main and fill lights as well as the lights illuminating the backdrop [because, from the camera position, the light is hitting the front of the backdrop]. All other lights, including hair, rim, and accent lights are considered non-front lights.

All front lights are metered with the dome of the incident meter pointed directly at the lens of the camera. Non-front lights are metered with the dome of the incident meter aimed at the light source. Three separate meter readings are needed in order to ensure a white-without-detail backdrop and crisp, clean separation lines on your subject. First, determine your working aperture and set it on the lens [recall that as long as you are at or slower than the camera’s sync speed, the shutter speed does not matter in a fairly darkened studio. Only extremely slow shutter speeds will risk recording the ambient light.] In my case, most of my commercial fashion work is shot at f/11. Determine what exposure you want for your subject and meter your main and whatever fill lights you choose to equal that predetermined setting. Your working aperture—what the lens is set to—may differ from what the lights are set for.

Now, meter the backdrop from the center of the backdrop and various other positions to ensure an evenly lit background. In my case, I am looking for an “acceptable spread” of between f/11 and 9/10 and f/16 and 2/10—1/3 of a stop. The backdrop is metered by placing the meter against the white seamless and a reading is taken with the dome of the meter aimed at the camera lens. The lights illuminating the front of my model is taken by placing the meter against her cheek, also with the dome of the meter aimed at the lens. The third reading is critical—you now need to make sure that the light blasting back from the white seamless reads less than your working aperture. The white backdrop is now a NON-FRONT light source because it is illuminating the back of your subject. Place the meter directly behind your subject with the dome pointed AT THE BACKDROP. If the reading is less than your working aperture then you are good to go. If it reads more than your camera setting, you are risking flare and image degradation and will need to move your subject farther from the backdrop [and re-meter and re-set the main and fill lights]. With a working aperture of f/11 my “safety-zone” for metering the light falling on my subject from behind is f/8 and 8/10 and under. I get a bit nervous when the light values are even, although that has worked.

I want the biggest and softest light I can find to illuminate white garments—especially when shooting against white backdrops. The details of the effects of the size of your light source have been discussed in an earlier article [“Using BIG LIGHT Sources,” Rangefinder, October, 2000]. However, it needs to be noted again that at any given distance from your subject, the size of your light source determines the quality of that light. Soft, even lighting is critical when shooting white garments—especially on a commercial lingerie assignment. A harsher light source will appear brighter on film—even at the same exposure—and you run the risk of losing detail in the delicate whites. You create a soft even effect by using the largest light source possible and bringing it as close to your subject as you can.

The young lady whose images accompany this article is Georgia Cobb. She is obviously a stunning young lady. However, she is also a great sport! I was working without an assistant so Georgia was busy climbing on chairs to change backdrops, moving lights and taking meter readings in addition to modeling and doing her own make-up! Many, many thanks to a truly beautiful person!

Dr. Stephen Dantzig owns and operates a small commercial photography studio near Studio City [LA area], California. His photography runs the gamut from commercial fashions to executive portraits and products/interiors. He is an award winning photographer and author of several articles on photographic lighting and ethics. Dr. Dantzig also conducts photography seminars from his studio.