Over the years we've covered portraits, both shooting and post processing them, and we've provided you with an amazing guide to depth of field, but never covered specific strategies. As a primer to this article, take a look at 17 excellent examples of narrow depth of field to get an idea of how depth of field can be applied to street portraits.
Street photography is a niche all to its own, but shooting portraits of either strangers or friends / clients can present a whole other issue.
Shooting in the streets
Unlike shooting portraits in a studio, shooting in the streets can offer endless opportunities for backgrounds, natural light and settings. The key to shooting a successful portrait in the streets however is that the focus should always remain on the person you're shooting. Environment and surroundings are only there to help accentuate the portrait. Don't get too hung up trying to find the perfect background setting, often times the most random of buildings, fields or textures can be the best. This will be explained later in the article.
Choosing the proper focal length
The focal length of your lens will determine how narrow or wide your depth of field is, and will in part be controlled by how much room you have. Ideally, portrait shooters prefer focal lengths between 70 and 200mm. If you aren't shooting posted portraiture though, and opting to shoot strangers as they pass by, shooting a lens in the 200-300mm range will suit you much better.
The right aperture setting
Since we've already explained in the guide to depth of field how aperture and focal length are used to create any desired depth of field, this article will be more focused on the strategies to achieve the desired effect, of which there are two.
The first look would be very narrow depth of field, where the person is in focus and the background appears very blurred. Shooting posed portraits, you want to be on a longer lens with a wide open aperture, f/4 or faster. Because there could be 10 yard or more between you and your subject, it could take a while to get the shots you need because of people walking past on busy streets.
In these portraits, there is a wonderful separation between subject and background, and as mentioned earlier, the background becomes less of the focus and used only to help show the subject is outside. For most, this will be the most desirable way to shoot. If your goal is to shoot strangers, the way street photography is done and not in a posed way, shooting wide open brings a small problem along with it. Because the depth of field is so shallow, the focus point becomes a concern when people are walking by, or even towards you. Choosing the focus mode on your camera that does continuous focus to track moving objects is a must.
The more uncommon method to shooting street portraits is with an f/stop of f/11 to f/16, where the subject and the background are both in focus.
While this has a very specific appeal to it, most will find that shooting a wide open aperture will yield the more desirable look.
Working with models in the street
Using the streets as your studio, regardless of which depth of field strategy you choose, finding the perfect place isn't always as hard as you may think. Remember, your portrait is your subject, they are the star of the photograph. Look for textures, neutral colored walls and areas of shade to help eliminate harsh shadows. Shooting within two hours of sunrise or two hours before sunset will give you the best light. Avoid private property and when in public places, be mindful of who is around. You don't want to disrupt the flow of traffic, put yourself in danger or the model.
Shooting strangers in the street
Shooting strangers can be much more difficult in the streets, consume far more time yet yield some amazing results. There are several photographers who shoot in the streets, both candidly and more aggressively. This video on YouTube shows how to easily setup a white backdrop and shoot portraits of strangers on the street, where depth of field won't play a major factor.
On the contrary, someone like street photographer Danny Santos [who shoots both posed strangers and candid strangers], the right amount of depth of field makes or breaks a shot. He often sits against a building for hours watching people cross a street corner for example, then picks out someone he thinks looks interesting and shoot. Narrow depth of field is the best way to single out a person in a crowd and put all the focus on them, thus making the portrait shot just that, and not one that contains a crowd of people. Bearing this in mind, in order to get such narrow depth of field, aperture settings must be f/2.8 or faster and on cloudy and overcast days, you could find yourself setting in camera ISO to 1,000 or even higher.
Regardless of how you approach the portrait, choosing the right strategy for how you pick your f/stop setting is almost more important than the setting itself. Before you shoot, think about what your goal is going to be, then the right setting will present itself and your goal will be attainable.