Monday, June 18, 2012
How To Photograph People Who Wear Glasses—06/18/12
Minimize reflections with a light positioned just right
|This Article Features Photo Zoom|
- Understand the angle of incidence. If you happen to shoot pool, you understand the concept of incidence and reflection. In layman's terms, it's the measurement of how far an angle of approach—be it a cue ball or wave of light—deviates from perpendicular to a surface. In practical terms, this means that the closer the light is to the camera position, the more likely you will see a specular reflection in the surfaces in the picture—from foreheads to backgrounds to, especially, eyeglasses.
- Move the light. Once you realize that the position of the light alters the angle of the reflection, you can begin moving your main light to remove it from the eyeglasses, which you can see from your camera position. For instance, if a subject were staring straight into your lens and you put the key light immediately to the left of the camera you'd see a strong reflection in the glasses. It might even obscure the entire surface of the lenses. Move the light up and to the left, and the reflection also moves up and to the left. Move up and to the left far enough, and soon the reflection will disappear entirely. This is, again, simply a function of angle of incidence equating to angle of reflection. Move a light far enough above or to the side of a subject and you'll eventually eliminate pesky reflections from their eyeglasses. You'll have to adjust the exposure accordingly as the light's distance from the subject increases, but that's easy enough to check with a meter or a glance at the back of your camera.
- Move the camera. Going back to that angle of incidence—which is triangulated between light, subject and camera—there's obviously another element that can be repositioned to change the reflection equation. It's the camera position, and just like a chin down movement serves to move reflections up and out of glasses, so does a higher camera position. If your subject is looking as far down as they can comfortably—or reasonably—be expected to look, it can help to raise your camera to a higher position and eliminate the last vestiges of the reflection. Ultimately it's some combination of changes to the position of the light, the camera and the subject himself that will go farthest to eliminate eyeglass reflections from your portraits, and keep you from having to make any repairs in post production—which is exactly what we'll cover next time.