You see it all the time in professional photographs; amazing portraits with the subject in front of a soft, blurred background. That beautiful baby or gorgeous model immediately draws your eye. How do they do that? Do you need years of training and top of the line equipment to make this happen? Definitely not! You do not need to be an expert or have an expensive lens to achieve this look. This is one of the easiest things you can try to add a new dimension to your photography. A little knowledge, your DSLR, and a kit lens are all that is required. I will describe simple adjustments you can make today to get that out-of-focus background and add artistic flair to your photos.
Before we delve into the practical application, it is important to understand the basics of aperture. If you typically shy away from technical discussions, I will keep this to a minimum. Aperture is the hole in your lens that lets light in to the camera body in much the same way as your pupil lets light in to your eye. Aperture is expressed in terms of f-numbers, which are also called f-stops. It can be a bit confusing but a low f-stop number means a larger aperture where lots of light is being let in to the camera. While a higher f-stop number indicates a smaller aperture, conversely less light is allowed in. So a photo taken at f/1.4 is a much larger aperture than a photo taken at f/8.0. You may hear a photographer discuss "stopping down" their lens. This simply means they are increasing the f-number, which allows less light in. On the other hand, if a photographer is shooting "wide open" that means they are using the largest aperture (lowest f-stop) available on their particular lens.
Depth of Field
Depth of field is the area of sharpness (from near to far) within a photograph. Basically, it is the portion of an image that is in sharp focus. There are several factors that influence depth of field, but the most important is probably the aperture you select. The focus of this article is achieving that blurred background look, and for that, you need to choose a shallow depth of field. Shallow depth of field limits sharpness to a single area in the frame and leaves the other objects and subjects deliberately out of focus. To do this use a small aperture such as f/2.8, f/4, or f/5.6.
Large Aperture/Shallow Depth of Field
If you shoot in auto or shutter priority modes your camera chooses the aperture for you. In some cases, you may get those soft, creamy backgrounds but you will also have lots of photos with sharp focus throughout. It is entirely out of your control and just depends on the aperture your camera chooses based on the light conditions. If the blur is what you are after, you need to take control and not leave it to chance. To blur the background and focus solely on your subject, you need to choose the aperture yourself. The easiest way to do this is to use the aperture priority mode on your camera. Typically you find this on your mode dial, and it is represented by an A or AV. Once you have selected aperture priority mode, select an aperture number and your camera will choose an appropriate shutter speed to properly expose the photo. You do not need to understand metering or shoot in manual to do this.
Take a look at your lens to see what apertures are available to you. If you are using a kit lens that can zoom, you will likely see a range of f-stops. For example, your lens may say 18-105 mm (those are the focal lengths) and f/3.5-5.6. This means that at an 18 mm focal length, the maximum possible aperture is f/3.5, whereas at 105 mm the maximum possible aperture is f/5.6. Other kinds of lenses have a maximum aperture that stays the same regardless of focal length. So, if you are shooting with an inexpensive kit lens, can you still achieve the nice creamy background? The answer is yes. Even if f/5.6 is the largest aperture, you can still get that shot.
Blurred Background With a Kit Lens
You must have depth in your composition in order to achieve the shallow depth of field. To blur a background, your subject needs to be away from the background. So, if you have your subject directly up against the background (i.e. a wall, like in the image below) there is no depth. The photo below is uniformly sharp and lacks depth. This creates a wonderful, sharp image, but if it is not the creative look you desire then you need to compose it differently.
You can create depth simply by separating your subject from the background. In the image below, the subject is further from the background creating a shallower depth of field and the desired blurred background. Go out and try it! Set the aperture of your lens to f/5.6 and try taking a photo of the same person at different distances from their background. When you view your images, you will see more depth and blurring of the background (even at the same aperture) with your subject placed further from the background.
Choosing a Lens
Now with the tips above in mind, the single easiest way to achieve a blurred background is to shoot with a larger aperture (lower f-stop). If you only have a kit lens, you will be limited. The lower f-stop your lens is capable of, the more artistic possibilities you have. Many of these beautiful compositions you see are shot with apertures of f/2.8 or lower.
Do you need to break the bank or sell your first born to buy a lens with a low f-stop? Absolutely not! Don't despair a 50 mm f/1.4 or 1.8 lens is high quality and actually quite affordable. With a 50 mm lens, you can produce sharp, colorful images with that artistic "wow factor" that low aperture allows. Another advantage to a low f-stop lens is it allows more light in, which gives you increased flexibility in low light situations. If you want to experiment more with low aperture and you are in the market for a new lens, you may want to consider a 50 mm. It will open up a whole new world of possibilities.
When to Use Low Aperture
Shooting with a large, low f-stop aperture is always a good thing, right? Not necessarily. What you are photographing and your goals for composition determine what aperture works best. Put some thought into aperture choice on a case-by-case basis. If you are on vacation photographing a cityscape, you likely want more depth of field. You need a larger depth of field to get everything in focus. The buildings and landmarks around you will be different distances away, and to capture the whole scene you want them all to be in focus. In this case, a smaller, higher aperture is in order.
A shallow depth of field can also be a problem when photographing people. In the adorable picture of the baby at the beginning of this article, the shallow depth of field is perfect. The baby is the focus, and the background has a dreamy, blurred appearance. Even for this type of photo, it is a good idea to choose an aperture of around f/2.8. Sure, you may have a lens that can go lower but you must remember that a lower aperture means less of your composition is in focus. You will need to practice with different apertures at different distances from your subject to achieve the desired sharpness. If your camera has a depth of field preview button it helps demonstrate what portion of the frame will actually be in focus at a particular aperture.
If you are taking a picture of a group of people, you also need to be careful about the depth of field. If you have a very large aperture and the people are at different distances from you (near and far), they will not all be in focus. You may photograph your kids' first day of school only to find that one of them is in focus and the other two are unrecognizable blobs in the background. Probably not the look you want to achieve! In the image below, the photographer chose to focus only on the woman in the background by using a very shallow depth of field for creative reasons. If you wanted to take a close up photo like this with both subjects in focus, you need to stop your lens down (choose a higher f-stop, smaller aperture).
Once you understand the basic concepts of aperture and depth of field, you can try some really fun, creative things! You may choose to focus on an object rather than the person in your photograph. This works well for shots of kids holding prized possessions in front of them at arm's length--like a picked flower or the first fish caught. It is also offers a unique composition idea for those birthday candle shots or, at sports events, try focusing on the ball or net instead of the player.
You probably don't want a whole library of blurry people, but it is fun to get some creative shots along the way. Using blurred objects in the foreground to frame your subjects also adds a nice effect.
The options are truly endless! You will be amazed at the artistic possibilities that aperture mode opens up. Even with your kits lens, you can employ the tips in this article to get that beautiful, blurred background. Step up your photography and add a creative dimension to your photographs today. Move that dial to A or Av and get out and take some pictures!
Most people think this post is Awesome. What do you think?