No Background Shadows Lighting Technique
High Key, One Light, White on White
Camera: Canon EOS 5D
Lens: Canon 85mm f/1.2L USM
Aperture: Setting: f/11
Shutter Speed: 1/125th handheld
Focal Length: 85mm effective
White Balance: 6000K
Camera Mode: Manual
Lighting: Hensel Integra Pro 1000 w/Chimera Octa 57 in 7-foot Configuration
Just before one of my Philadelphia photography workshops, my model, Tess, wanted me to photograph her in a new outfit, white pants, white top, white shoes, so I decided to make it a high-key shoot, white on white with no shadows. The challenge was to ensure the whites would not blend into the background and in this “how-to” we’ll explain how easy it is to ensure the whites would separate from each other—and this was all done with one light!
The Story Behind The Photo
Just before one of my Philadelphia photography workshops, my model wanted me to photograph her in a new outfit she had purchased just for the workshop. When I first saw it, all white, I immediately thought about a high-key photo shot and the 90-percent rule of reflectance in photography, what is pure white reflects 90-percent of the light that hits it, what is pure black, absorbs 90-percent of the light that hits it. You have to consider this rule as the model’s skin is tan, thus her skin absorbs more light than any white, and when you expose for a darker skin tone, it’s easy to blow-out any detail in white.
Human skin tone is not pure white or pure black; that is one reason why gray cards are based on 18-percent gray reflectance and light meters are calibrated to a luminance value equivalent to 12-percent gray reflectance, thus a neutral tone that closely matches the middle point from full white to full black. When we take the 90-percent rule into account, we adjust from the light meter reading value—if a model’s skin tone is darker than average skin tone, we open up about one-third of an f/stop, if the model’s skin is lighter than average, we stop down about a third of an f/stop. Light meters only give starting points based on luminance and reflectance.
I also wanted to make the photo more interesting as most photographers would normally take a photo of a blonde model wearing all white with a black background, so the whites would not bleed into each other. I wanted to make it interesting, white on white, high-key, so we added a white chair for the model to sit upon, and then placed clear plexiglass underneath the chair to capture a mirrored type reflection. Furthermore, we also decided to light the whole set with only one light. This is easily achieved by taking into account the Inverse Square Law and the Law of Reflectance, plus the 90-percent rule of light.
The first challenge was to light the high-key set so the background would photograph as a true white without any shadows from the subject or the chair. Photographers traditionally light high-key sets by placing two-lights close to the background, then pointing them directly at the background. Depending on how white the photographer wants the background, they adjust their main subject light output to either match or be at least a half to full f/stop less than the background lights. The problem with this is they rarely take their subject’s skin reflectance into account while making these adjustments.
On a high-key set, If we look at the background as a big white reflector, it’s easier to light the set using the Inverse Square Law while considering the Law of Reflectance. The Inverse Square Law Inverse Square Law simply states (in photographic use), when you double the distance of the light to your subject you’ve reduced light intensity falling on your subject to one-fourth of the original amount. Keeping that in mind, if your model is four feet from the background, and the main light is four feet from your model, the light striking the white background is 1/4th the amount striking your subject, thus the light reflecting off that background into the camera lens is 90-percent of that.
Now who has time for that complicated math? I don’t. The easy thing to do is to mark a spot for the model where the light striking her back is 2/3 of an f/stop less than the light striking her in the front, though adjusting for her skin tone under the 90-percent rule. This will give you a perfectly balanced white background with no shadows every time. The easiest way to do that is to place the flash light meter in front of your chest facing the light source and then take your reading. Then without moving your body, place the light meter behind your back and point it at the background and when you fire the flash, you’ll be measuring the light reflected off the white background. You place the meter behind your back to block off the light coming directly from the flash unit.
Take note of your readings and move forward or backward slightly until you get a reading where the background reading is approximately 2/3 of an f/stop value less than the meter reading from the chest pointing at the direct flash unit. Basically you are taking advantage of the Inverse Square Law in this situation to give you a perfect white, all with one light!
The second challenge was to ensure that the whites from the clothes, shoes, chair, etc., would not blend into the background. Here again, this is where the 90-percent rule comes into key play. We simply took two V-flats, with the black side facing the model on each side as close as possible, but out of camera frame. Pure black reflects at least 10-percent of the light that strikes it back with dark tones onto the model’s clothes, the chair, etc., thus putting back detail in the white, which helps give separation from the white background. Basically the V-flats are subtracting reflected light from the whites.
A V-flat is simply two-foam core panels, 1/4-inch thick and available at your local graphics supply house, 4-foot by 8-foot in size, taped together with black tape standing up tall, and closed in a V shape so they can stand up on their own placed on each side of the model. It’s important to place these V-flats as close to your subject as possible for maximum effectiveness, while keeping them out of camera frame. This acts as four large sheets of black around your subject subtracting light.
The third challenge is for the photographer to move until the model’s reflectance is favorable on the plexiglass. The physics rule that applies here is the Angle of Incidence is Equal to the Angle of Reflection, or the Law of Reflection. Basically by having the modeling lamp turned on the Hensel monolight studio flash unit, you move until you see the reflection on the plexiglass through your camera lens.
In the end, we overcame our challenges rather easily and Tess provided some great looks for me to capture a great white on white photograph. It also helped Tess and I had worked together before, the more you work with a subject, the easier it is to capture great photos, especially headshots, or a beauty headshot shot in this case.
There were no real safety concerns during the creation of this white on white photograph was to properly secure the light stand to ensure it wouldn’t fall as the Chimera Oct 57 is rather large and top heavy when attached to the Hensel Integra Pro 1000 monolight. We secured the C-stand with sand bags and ensured the electrical cord ran underneath the light stand so the stand would slide if someone were to trip over the electrical cord. If you do not place your monolight’s power cord under the stand legs, and someone trips over the cord, chances are your light will fall completely over vs. sliding across the floor.