If you've spent a lot of time on Flickr looking at sunset photos (and if you haven't, you should be!) you may have noticed a commonly-used technique. Many photographers include silhouettes in their sunset images. That's not just because sunset conditions are perfect for photographing silhouettes, but also because there's something about a silhouette that people just automatically love. A silhouette isn't a direct line to your viewer's heart, but it's pretty close. And portfolios love silhouettes, too—what would a travel photographer be without one or two images of a beautiful sunset in an exotic place, featuring a silhouetted couple holding hands on the beach?
World's Favorite Sport by Flickr user vramak
What is a silhouette?
A silhouette is simply an area of a scene where the detail has been lost to shadow. Ideally, a silhouette is an identifiable shape—a tree, for example, or a person. Silhouettes are typically black from edge to edge, though you can make a very strong image with a partial silhouette, which is simply a subject that is dark but not necessarily without detail. If there's any sense of third dimension in a shape, it's a partial silhouette. True silhouettes are simply shapes—they appear completely black, have no detail and no sense of depth or dimension.
Partial silhouettes like the one above give a sense of form as well as shape.Butterscotch World by Flickr user Kuzeytac
How to choose your subject
Not all subjects make good silhouettes. A person who is facing the camera, for example, doesn't make a very compelling silhouette because all you get is the shape of his or her head and shoulders. But if you turn that person to the side so you're shooting his or her profile, now you have some definition—some identifiable features such as nose, chin and forehead. The same is true for any subject—before you choose the angle to shoot your potential silhouette from, you need to try and picture what it will look like without any color, detail or form. If it's going to be an unidentifiable blob, choose another angle. If it's going to be an unidentifiable blob from that angle, too, you might need to choose another subject.
A nice shot, but would have looked better with the subject in profileUntitled by Flickr user Zawezome
Keep in mind, of course, that changing your angle is also going to change the position of your light source—that setting sun and/or the bright sky around it. If you have to change your angle so much that the subject is no longer back lit, then you can't use it to create a silhouette.
And that brings me to my next point—the light. You're shooting at sunset, so you (hopefully) already are planning to place your subject in front of that dramatic sky. In order to achieve a silhouette, your subject must be back lit. Side lighting and front lighting is going to add detail to your subject—back lighting is going to subtract detail. Make sure that your light source (in this case, the sun or sky) is always behind your subject. You can position the sun itself directly behind your subject, or you can simply use the bright sky near where the sun is setting—with the right settings, either one is going to give you the results you're looking for. Just take care that there isn't any visual clutter in your image--ideally, you want open sky around your subject. That's going to not only give you the most light to work with, it's also going to provide the backdrop against which your silhouette will stand. What you don't want is for her to be placed in front of other silhouettes, then she'll just blend in and you won't be able to separate her from her background.
Sun Down, Coachella 2013 -- Indio, CA by Flickr user Thomas Hawk
Get your settings right
The key to mastering the silhouette is to understand your camera's settings. Once you have your subject identified and placed in front of the light source, you need to make sure the settings you choose are going to create the effect you want. Auto mode is out, because auto mode is going to try making your scene into an 18 percent gray, and that's not what you want.
There are two effective ways to capture a silhouette, and either one will give you a good result. The first is to use aperture priority mode and exposure compensation. Set your camera to f/8 or f/10. You don't need to have a whole lot of depth of field when you're shooting a silhouette, so choosing a mid-range f-stop is going to give you the best results. Now select an exposure compensation of somewhere in the -1 to -3 range. As a general rule, a brighter sky will require somewhere in the neighborhood of a -3, and a darker sky will be in the -1 range. For best results, though, bracket. Take one at -1, one at -2, and one at -3 and compare results. One of the three is likely to be your favorite.
The second technique for getting a silhouette is to use manual mode and spot metering. This is a pretty simple process, too—just aim your spot meter at the sky instead of your subject. Change your shutter speed until that needle in your viewfinder lands on the "0" (keeping the aperture in the mid-range, if possible), then recompose and shoot. By metering for the sky, you'll get a subject who falls into shadow and becomes a silhouette. It's still a good idea to bracket when using this technique, since that spot meter is designed to expose for 18 percent gray, and your sky may or may not qualify. So bracketing a few shots at and around your spot meter reading is, once again, going to give you the best chance at success.
Silhouettes are compelling, and loved by almost everyone—that's why they are such popular elements in sunset photographs. Remember that you can capture a great silhouette almost anywhere, during any sunset, just by following the guidelines I've given you above. And if you do it well, you may even be able to convince your friends and family that that beautiful silhouette you shot in your back yard was actually captured in some exotic location on your last vacation.