In this article we’ll create a soft light by using two softboxes to do the work of both key and fill lights, yet look like only one source. The reason this will work so well is that the lights will be placed very close together, and each side will be individually controlled.
I’ve said many times (and it’s true, every time) that larger sources equal softer light. It’s also quite true that softer light makes more mature clients look better because it tends to wrap around those badges of age, wrinkles. While I have no problem with such things, and have certainly earned every one of mine, I can also understand why someone would want them minimized. This light will do that beautifully.
Begin by setting up two softboxes, the larger the better. I used my two large 4x6 boxes, but two medium boxes will work as well, provided they are set closer to the subject. Also, bear in mind that this technique will work best on no more than two individuals together, because the light on one side or the other will be dimmer.
Turn the boxes at an opposing angle of approximately 45 degrees and set them close enough that their corners almost touch. Rack both of them to the correct height to get a proper nose shadow. The angle between the boxes will allow you to shoot through them while the height will make the light attractive. Center the subject between the two boxes. Here’s a model’s eye view diagram of the lights:
Meter the output of each light individually. I wanted the light on camera-right to be one stop less than the other, and the only way to be accurate was to measure them separately. When you have the correct ratio, measure them together, as the output will change. This new reading is the working aperture. If you must tweak the power output to reach a whole stop or perfect third, do it on the lower-power side. The adjustment won’t be more than a tenth or two of a stop, and will not seriously impact the look of the light.
For my first shot, I placed my model six feet from the background, a gray-painted wall. Because she was relatively close, the two lights, positioned about six feet from her, lit the wall nicely and returned a tone slightly darker than its actual value.
I liked the effect, but felt the shot would be more dramatic with a darker background. The solution was very simple: I moved the model another six feet from the background, and moved the two lights to keep them the same distance from the model. The amount of light that fell on the model was exactly the same, as was my working f-stop, but the light on the background was only one quarter as strong, reducing the value of the light gray wall to a charcoal gray wall. This is just one of the many ways you can make the Inverse Square Law work for you to control the look of your images.
This will also work if both softboxes are set vertically, although the catchlights in the subject’s eyes may have a look more like a cat’s eyes, especially if the lights are very close. This is not necessarily a bad thing; you’ll have to make that decision for yourself, as there’s no rule about such things. It’s all about the look.
Like horizontally placed softboxes, the effect of power output differences is subtle but valuable. The next image was made with two large softboxes set vertically and with equal power. It’s quite lovely.
Without moving anything I stopped down the power of the camera-right softbox by one stop. Those of you whose strobes do not power down in equal stages will have to re-measure one strobe against another, one at a time, to get the correct output, then meter again to get a final working aperture. If your gear powers up or down in equal stages, you’ll still have to re-meter to get a new working aperture. That's because the working aperture will change, and the change must be dealt with or your exposure will be incorrect. As I said earlier, the effect may be subtle but it sure is beautiful.
As I always do, I suggest you find a subject and play with this technique until you thoroughly understand it. You may find you like a difference of as little as 1/3 stop or as much as two full stops. It’s entirely up to you, and can be one more of the many things that will distinguish your work from that of others.