Contributing editor Jim Richardson is a photojournalist recognized for his explorations of small-town life. His photos appear frequently in National Geographic magazine.
Getting things out of focus takes work.
Of course I'm not talking about my usual out-of-focus pictures, the ones I delete immediately and never tell a soul about. No, I'm talking about the intentional things we photographers do to limit the depth of field in our pictures. Things we can do to make the backgrounds nice and soft, leaving just the subject in focus and standing out dramatically from its surroundings.
I still remember the time, some 50 years ago, when I first realized how cameras could be set to produce this effect, marveling at the sorts of images I saw W. Eugene Smith producing for Life magazine. Or the sorts of stark images David Douglas Duncan could evoke from the battlefields of Korea, just the eyes of a dead-tired GI in focus, searching for relief from weariness.
The standard formula for controlling depth of field is to control the f-stop of the lens. And that is true enough. A wide-open aperture results in a shallow range of focus, and a small aperture gives you lots of depth, with almost everything in focus.
Mostly that's true, as far as it goes, which really isn't very far. And there are several important caveats to these mantras, and some other really important criteria to consider if you really want to make the effect work.
Here are a few tips:
- F-stop matters somewhat less than is generally taught. Yes, you can control the range of focus from any given subject distance, but just controlling the f-stop won't usually turn a crystal-sharp background into a dreamy-soft background.
- Closeness to subject matters a lot. Put simply, if you really want to throw the background out of focus, get really close to your main subject. Even an extreme wide-angle lens like my Nikkor 14-24mm f/2.8 has a really shallow depth of field when the subject is six inches [15 centimeters] in front of the lens. Getting close to your subject has a huge influence on the background sharpness.
- Relative subject distance matters a lot, too. Separating your subject from its background by a large relative factor is a powerful way to control depth of field. If the subject is two feet [0.6 meters] away and the background is 50 feet [15 meters] away, you get very shallow focus. On the other hand, I remember shooting football games in bright sunshine and trying to make the players stand out from the crowd behind them. If the players were on the other side of the field and the crowd was just a bit farther off it didn't matter what f-stop I used, even with a 300mm f/2.8 lens. But just a little change in angle put the crowd further away and the players popped out nicely.
- Get lower to the ground. Huh? This sounds really stupid. But consider this: If you are standing up while taking a picture of a flower on the ground, then the background behind the flower is virtually the same distance away. But if you get down low the background is now much, much farther away and perfectly out of focus. This phenomenon was well known in the days of twin-lens reflex cameras, which were easy to set on the ground and view looking down into the viewfinder. Take a look at fashion photos from the '50s shot on a Rolleiflex to see the effect. Works like a dream.
- Choose a background lacking in specular highlights. Lots of small bright highlights are always harder to get pleasingly out of focus than something large and featureless. (And if the background is a perfectly plain sky it probably doesn't need to be out of focus at all.)
- Get a bigger camera. If you have a point-and-shoot then get a digital SLR. If you have a small-chip DSLR, then get a full-frame DSLR. If you really want out of focus, get an 8x10 camera. The physics of lenses is such that the larger the actual film or sensor, the less depth of field you have. Point-and-shoots have extremely short focal-length lenses, resulting in just about everything being in focus no matter what you do. (If you are a depth-of-field junkie and want to argue this point, then read on to the next item, where you'll find even more to harrumph about.)
- Get a longer lens. Physics again. The longer the lens, the less depth of field—in practice. Wide angles have more depth of field and telephotos have much less—in practice. (If you are a depth-of-field junkie I can already hear the howls of protest on this one. Yes, I know all the arguments and the way depth-of-field discussions turn into raging flame wars on the Internet. But for the general practice of photography as done by working photographers, this is true enough to prescribe.)
- Buy a tilt-and-shift lens and use it wrong. The tilt part is what comes into play here. The effect of tilting the lens to produce more depth of field has been known almost since the beginning of photography. And generally that's what a tilt-and-shift lens is used for (beside keeping tall buildings from falling over). But there is nothing to keep the creative photographer from doing it "wrong"—tilting it the other way and decreasing the depth of field by a lot. It can look very cool. On the other hand, it seems everybody in the world now knows this trick, which means it will soon enough be passé.
- Buy a Lensbaby. This is a tilt-and-shift lens (minus the shift part), combined with a lens element that makes the edges of the image pretty soft to begin with. Great fun to play with and it gives you just huge control over depth of field (as long as you want less).
- Just reach for the "blur" brush in Photoshop. Most any software today gives you abundant options to blur a picture and then paint back detail where you want it. But realize that when you do this you are seriously getting into the world of "fiction" photography. It might be beautiful and dramatic, but be very careful that you don't represent the resulting photograph as being "nonfiction."