FOUR STEPS TO SHALLOW DEPTH OF FIELD
A shallow depth of field occurs when your subject is in focus, but the area in front and behind it is out of focus. It can draw attention to a single object by isolating it from everything else in the frame. After all, if only one part of the photo is in focus, that is where the viewer’s eye will naturally settle.
Many people I speak to understand one or two elements used to create a shallow depth of field. But did you know there are actually FOUR factors that contribute to depth of field, and if you only apply one and ignore the others, you won’t get results like the main picture at the top of this page.
Distance between subject and background. The best way to separate the subject from everything else is to…separate the subject from everything else. If there are background objects very close behind the subject, they may be slightly out of focus, but still clear enough to draw the eye and potentially create a distraction. However if you have significant distance between the subject and the background it becomes much easier to isolate it. This first point is so important that without it, the next three items on my list will have little impact.
The size of your lens. The larger your lens (in terms of magnification) the shallower the depth of field becomes. So a 200mm lens produces a shallower depth of field than a 100mm lens. When you use a lens with a very short focal length (i.e. a wide-angle lens) the depth of field can be so strong that virtually everything is in focus. So if you really want to isolate your subject with a shallow depth of field, start by using a telephoto lens.
Distance from the subject. The closer you get to the subject, the shallower the depth of field becomes. Try taking a photo of a small-ish object from five metres away with a telephoto lens, then take notice of the depth of field. Then photograph the same object from two metres away (with the same lens). Right away you will notice how much shallower the depth of field becomes.
Note: this is one of the things that makes macro photography so challenging. When photographing something tiny from only a few centimetres away, depth of field can become so shallow that it’s hard to keep a whole ant in focus. But for regular telephoto photography for subjects like people and wildlife, it is a sure-fire way to isolate a subject.
Aperture. That’s right, aperture is the last item on my list. Why? Because in some ways it is the least important factor in creating a shallow depth of field. Our theory tells us that a wide aperture (small F-stop) produces a shallow depth of field. But the effectiveness of the aperture depends on our first three items – distance between subject and background, size of lens, and distance of camera from subject. So changing the aperture will make very little difference if you are shooting from a long way off with a wide-angle lens. But if you are close to the subject with a telephoto lens, then the aperture can be used to ‘fine-tune’ the depth of field to create just the effect you want.
Summary. So if you want to produce a shallow depth of field to really isolate a subject, follow four simple steps.
- Make sure there is space between the subject and the background.
- Zoom in.
- Get closer.
- Open the aperture as wide as it can go.