Edge Separation. That lesson I learned 20-something years ago was about edge separation for enhancing the illusion of depth. When working outdoors, by putting the sun behind the subject and adjusting the exposure for the shadow side of the subject we’re now facing, you create a thin band of light along the edges of the subject—whether that’s a soccer player or a senior portrait—which serves to distinctly demarcate the edges of the subject, enhancing the feeling of depth. In the studio, the same technique can be done with strobes and strip softboxes placed just behind the subject and just outside the frame, or by using gridded spotlights well behind the subject. Be sure to place them above shoulder level to keep from creating a strange shadow on the subject’s cheeks and neck. To create a very thin edge light, hide the source directly behind the subject and it will illuminate a thin outline around them.
Enhanced Texture. One of the benefits of lighting from behind is that it casts shadows toward the camera. Even if they’re off-axis by nearly 90 degrees based on a light position nearer to the side of the subject rather than behind, still there will be the appearance of enhanced shadows falling generally toward the camera. And anytime you increase shadows like this, you’re also increasing the appearance of texture. Even when used with a soft light source such as a cloudy sky or a strobe in a softbox placed opposite the camera, the position of the light is enough to rake across the surface of your subject—the grass in a field or the nooks and crannies on old weatherworn wood—and create the shadows that tell our eyes about texture. If you’re trying to maximize texture, work to position your light close to the same plane as the surface you’re illuminating. The more you’re shooting into the light, the more pronounced texture will appear.
Frontal Fill. If you find that the subject is too strongly backlit to expose correctly just by opening up the aperture or slowing down the shutter speed, you may need to add a frontal fill light to decrease the contrast ratio in the scene. This can be done with a softbox on a strobe or a simple white or silver reflector. However you decide to do it, be careful not to overdo it. A lot of the charm of backlighting comes from prominent, deep shadows presented toward the camera. That charm is all but eliminated when the frontal fill is too strong. So my technique tends to be increasing the fill until it’s noticeable on the back-of-the-camera LCD, and then backing it off by a third or a half stop to ensure it’s not too bright. A little bit of frontal fill goes a real long way.
Watch Out For Flare. Whenever you’re shooting toward any light source, the biggest challenge is avoiding lens flare. Flare robs shots of saturation, contrast and sharpness. Sometimes it sneaks into the frame even though you can’t see the light source with your naked eye through the lens. Other times the source is distinctly in the shot. In either case, you’ll need to take care to avoid problematic flare. This task is made easier with the use of flags, or by strategically positioning the camera so that existing structures such as trees create temporary flags by blocking direct sunlight from hitting the lens. Another option is simply to go with the flare and make it part of the compositional elements in the picture. This trend has increased in recent years, as flare is now seen as a hallmark of candid, authentic, off-the-cuff photography. So if you want to add a bit of “realism” to your picture, consider strategically letting the light source creep into the frame for flare.