Depth of field (DoF) is one tool that will make your images more powerful and interesting. It is an artistic focusing choice with a technical foundation.
In this article, I’ll help you understand depth of field and how you can use it in your own photography.
Understanding Depth of Field
Depth of field in photography describes how much of your scene is in focus. Technically, depth of field is the distance between the closest objects in focus and the farthest point of focus. Imagine looking out into a landscape through your camera. Depth of field starts at the first thing you see that’s in focus and extends to the furthest object in focus.
Deep and Shallow DoF
We talk about depth of field in terms of “deep” and “shallow”. Deep DoF is also called “wide” or “large”. Shallow DoF is also called “small” or “narrow”.
Landscape photographers often want the entire scene in focus, from the closest rock to the furthest mountain. This is a “deep” depth of field.
In this image, the waterfall in the background and the rocks in the foreground are both in focus.
Portrait photographers don’t necessarily want the entire scene in focus. If you’re walking around a city taking street portraits, you want the person to be the main focus. A distracting background should be minimized. To do this, you use a shallow depth of field. Your foreground is in focus, but the background is not.
In this image, only the foreground holy man is in focus. The background gives a sense of the environment without distracting from the foreground.
Shallow DoF is a great way to separate your foreground from the background. The background might be uninteresting or distracts attention from your subject. Check out this article about more ways to use shallow depth of field.
It is possible to cleverly combine shallow and deep DoF in one photograph. In this image, the photographer used a smartphone to capture a wide DoF. Then photographed the image using a shallow DoF.
I’ll show you in a minute how to achieve deep and shallow depth of field. But before I do, there’s one more thing you need to know about the focus area.
What is Focus Distribution?
Focus draws the eye. So as a general rule, you should focus on the point of greatest interest. Depth of field tells you how much of the scene will be in focus in front of your focus point and how much of the background will be in focus.
When you select a focus point, focus isn’t equally distributed in front of and behind this point. Often one-third of your focus falls in front of your focus point and the other two-thirds behind it.
The DoF calculator also tells me the hyper focal distance. This is important for landscape photographers.
Hyper focal distance tells me where to focus in the scene so that I’ll have sharp focus all the way to infinity. Infinity is as far as the eye can see.
In landscapes, if you focus on the foreground, the background will appear blurry in the image. If you focus on the background, the foreground will look out of focus. To fix this, focus needs to be somewhere in the middle, between the foreground and background. This focusing point is the hyper focal distance.
Now that I’ve introduced you to the DoF calculator, play with it a bit. Enter your camera body and different focal lengths. Notice that the numbers change. All sorts of factors control depth of field.