This is one of my favorite types of lighting set-ups, and is the kind of lighting you may observe if experimenting with a continuous-light softbox–try it, and you’ll discover all kinds of interesting lighting set-ups. The basic set-up is to position a large soft source slightly behind your subject so that the light wraps gradually around the front of your subject’s face. This creates a subtle gradient from light to dark, producing a wide range of tonal values.
While the photo at the top of this section could’ve just as easily been lit using a large softbox or octa, I happened to use multiple layers of diffusion to produce an extremely soft source. Starting with a single source, an 18″ beauty dish, I first diffused the beauty dish with a 24″ x 36″ Polysilk, then added a 39″ x 39″ Westcott ScrimJim with a 1.25-stop diffusion panel attached:
The final diffuser, the Westcott ScrimJim, becomes the final source size, and was placed just a few feet from the subject, making its relative source size fairly large, which also produced the maximum amount of wrap. Notice how the light gently wraps around the subject’s face from left-to-right, revealing subtle detail as it approaches the shadow side, even though no supplemental fill light or reflector was used.
Often used by cinematographers, this technique of projecting light through multiple layers of diffusers is a popular lighting application on movie and TV sets. Directors of photography will typically instruct their key grip to place increasingly dense layers of diffusion, as the diffusers also become increasingly larger. A larger-scale example of this technique would be to start with a soft source (e.g., a 4K Mole-Richardson softlight), then rig a 4′ x 4′ Matthews’ Polysilk in front of that, followed by a 6′ x 6′ light gridcloth on a frame.
More importantly, if you notice in any movie, or well-produced TV show, actors’ close-ups are almost always lit with the key coming from the side of the face opposite camera. This reveals the gradient, from light to dark, across the actor’s face, and is favored by cinematographers because it tends to be the most interesting light. In fact, this is a common approach also used in food, product, and all sorts of commercial photography because light which comes from slightly behind the subject is simply more interesting to look at.