Depth of field – the most powerful tool a photographer has?

Depth of field, DoF for short, is the area of the photo which appears well focused. It is controlled by three factors – the aperture, the focal length, and how far away the subject is from the camera. 

1. Using the aperture (f-stop) of your lens is the simplest way to control what parts of the scene that are in focus. The lower the f-number, the smaller the depth of field with be. And, the higher your f-number is, the larger your depth of field.
2. If you place your subject close to the camera, your focus area becomes more shallow. By moving further away from your subject the depth of field will deepen.
3. The longer your focal length is, the shallower the area of focus.

Here are some key points on depth of field:

• The focus area is usually about one third in front and two thirds behind your focal point (meaning the thing you are focusing on), but as your focal length increases it becomes more equal.
• Learning to manage what part of the image you want to be in focus, and which parts you want out of focus, is one of the most important tools you have to create great images.
• I recommend using a shallow depth of field to make your subject stand out from its background, like when taking portraits or storytelling pictures.
• In landscape photography it is often important to have a lot of the scenery in focus as possible. By using a wide angle lens and a small aperture (high f-number) you will be able maximize your depth of field.
• Did you know there is a button on your camera that can give you a preview of the focus? Most cameras have it – the DoF preview button. You can also find helpful apps and charts to give you a sense of what will be in focus.
• You’ve probably heard of bokeh – it’s a big deal to many photographers. It is out of focus areas created by the shape of the lens aperture.
• Take control of the DoF! You can even do so with a point and shoot camera. Look for a symbol of a human head, when you are shooting portraits to give you a narrow depth of field. The landscape setting is a mountain symbol, which will give you a deeper depth of field.
• There are some simple ways you can control depth of field using a DSLR even if you don’t feel ready to start using manual mode. If you choose Aperture Priority mode you are able to set your aperture to get the focus area you want, and the camera will automatically set the shutter speed to create the correct exposure.

Good luck, and don’t be afraid to play around – it’s the best way to learn. If you have any questions, let me know in the comments below or contact me directly.