Monday, August 20, 2012
Position Your Lights Properly To Make Better Photographs—08/20/12
Where to place a light to increase texture, show shape, hide flaws or add drama
|This Article Features Photo Zoom|
When photographing a human face, your primary goal is to make your subject look good. Your job, in most cases, is to simply accentuate their positives and hide their flaws. Most portrait photographers know that a large, soft light source (like open shade, window light or a softbox) is a great way to create an appealing, flattering portrait light source. But that's only part of the challenge. Where you position that light changes quite a bit in the end result.
The Product Photo
If you're lighting a product, be it a loaf of bread you've baked or a bottle of detergent you've been hired to photograph, your principal concern is to render the shape and texture of the subject both accurately and in an appealing way. This is especially true in a commercial situation in which a client is spending money to make their product look its best; if you don't know where to position the light to accomplish that, you're not going to be in business for long. But even if you're not hired by clients to make commercial product images, you're clearly photographing an object with a purpose in mind—and it's usually because you like the way it looks and want to make it look equally lifelike and appealing in your photograph. The point is, positioning the light to accurately show the item's shape and texture is paramount.
A frontal light position is probably the worst place to start with most product photos, for precisely the same reason it can work well with portraits: it eliminates shape and texture. Instead, to show that a box is three dimensional, for instance, you'll want to position your light at 45 degrees to the side and above the subject. This way you'll have a highlight on one visible plane, a shadow on another, and with a fill card on the third you'll clearly illustrate the three-dimensionality of the product with three distinctive tonal values.
If texture is an important part of the subject—say, it's a textured doormat or a bristly hairbrush—that texture can be amplified with the help of shadows. A light to the side, be it 45 or 90 degrees, and in a low position where it is raking across the surface of the subject—which can sometimes even be from behind—will create lots of little shadows that subconsciously inform our brains that we're looking at something with texture. Our brains know that flat means no texture and shadows mean shape and texture. Exploit that with the correct light position and you'll create the perfect product photo.
Shiny surfaces can be found in any photographic situation, no matter if your subject is a person, a place or a thing. Everything from eyeglasses on faces to stainless steel in kitchens to mirrored or reflective surfaces on a variety of products counts as a shiny—or specular—surface. And when photographing specular surfaces, you've got to remember one thing: you're not lighting the surface itself, you're lighting what it "sees." That means if you want to highlight the shine in a pile of old coins, you'll find that a key light positioned directly above the camera is ideal for creating a highlight on the surface of the coins. (That, of course, is contingent upon the angle of the camera to the subject; if your camera is off to the side, you'll want to place the light off to the other side at the perfect angle to reflect light back into the lens.) You'll also need to ensure you're working with a softbox rather than a specular source in order to create a broad, flat highlight across those shiny surfaces. A specular light and a specular surface just don't mix.
The reverse holds true, of course, when it comes to reflective eyeglasses on the faces of your portrait subjects. If you don't want them to be obscured by highlights—which usually you don't—you'll need to be sure you position your lights where they're not reflecting back into the camera. So in that case, with your camera square to the plane of the eyeglasses, move the lights beyond 45 degrees from the camera axis. That will ensure that the highlights don't shine right back into the lens.
I know, I know: a "dramatic image" could be just about anything, so how do you light "just about anything"? In this case, I mean how do you light to give something more drama? One way is simple: create a high-contrast look by separating the subject from the background with edge lights. Increase the contrast between these edge lights and the frontal key light to increase the drama even further, and consider making the whole image fairly low-key so that the bright edges really pop and make a big impact in a simple shot. That's how you light anything dramatically. To make those edges pop, you can't have your lights in front—they've got to be behind the subject, backlighting it.
Of course, the phrase "behind the subject" still leaves room for interpretation, so here's a good way to distinguish between the effects of a light positioned directly behind the subject and one positioned 45 degrees to the side, but still behind the subject. The farther to the side the lights are positioned, the thicker the edge highlights will be. For a very thin rimlight (or edge highlight) you'll want the light positioned directly opposite the camera, right behind the subject. And of course, though it should go without saying, a small, specular light source will produce a thinner edge light than a large, softbox light source will. And any time you place your lights behind your subject you've got to be on the lookout for your arch nemesis, lens flare.