Depth of field is one tool you should be using to make your images more powerful and interesting.
Depth of field is an easy concept to understand and use. There is no reason why you can’t start using it today.
Chances are you have already started using depth of field photography, you just don’t know it.
Understanding Depth of Field
What is ‘depth of field’? It’s simple. At its most basic, It’s how much of your scene is in focus. That’s it.
And here’s a more complicated definition. Depth of Field is the distance between the closest objects in focus and the farthest point of focus.
Consider this. You are out photographing a beautiful landscape. And you want to be able to see the whole scene for what it is.
Here, you would use a deep depth of field, as it will keep your foreground and background in focus.
Here, your foreground is in focus but the background is not.
Your aperture or ‘f/stop‘ is what indicates your depth of field. If you don’t know about aperture, then you need to read this post first.
The wider the aperture, the shallower the depth of field and vice versa. The diagram below explains this.
The smaller the depth of field, the smaller the area of focus will be. This focal area can be placed anywhere in your image.
You can use it to put the background, the middle ground or the foreground in focus. The choice is yours.
A small aperture such as f/1.2 can put the eyes in focus, but keep the nose and ears blurry.
Using the same f/stop, you can focus on the nose, which will blur the eyes.
Large aperture = Small f-stop = Shallow (small) depth of field
Small aperture = Large f-stop = Deep (large) depth of field
Is Depth of Field Equally Distributed in Front and Back of my Focus Point?
When you place your focal point on a subject, there is a depth of field range. This means that before and after that focal point is a distance where everything in focus. The larger the narrower the aperture, the larger the distance.
But, is the distance before and after the focal point the same? You would have thought it was, but it isn’t. Usually, one-third of your focus falls before the focal point, and the other two-thirds behind.
At 10 meters, the 50 mm gives a depth of field of 12.4 m. It starts at 6.77 m and finishes at 19.1 m. This means that there is a 3.23 m focus before the focal point and 9.1 m behind.
With the 200 mm, you get a 0.59 m depth of field. It starts at 9.71 m and ends at 10.3 m. As you can see, 0.29 m falls before the focal point, and 0.3 m falls behind it.
How Does the Focal Length of a Lens Control Depth of Field?
The focal length of the lens is how close you can photograph a subject. A wide focal length lens, such as 14 mm will give you a field of view of 114°. A telephoto lens with a 200 mm focal length gives you a 12°.
Without becoming too overcomplicated, a longer focal length will give you a shallower depth of field. Let’s look at an example:
Images that show selective focus have a shallow depth of field. This means that the range of focus is very small. Let’s look at an example using two different lenses. The Canon EF 50mm f/1.2 L and the Canon EF 200 mm f/2.8L.
Let’s say your subject was 10 meters from the camera. By using a focal length of 50 mm at f/4, your DoF would be 6.77 – 19.1 m. Everything between these distances (12.4 m) will be in sharp focus.
If you were to change your lens to the 200 mm, using f/4, your DoF would be 9.71 – 10.3 m. This gives you a total depth of field of 0.59 m. To achieve the same depth of field as the 50 mm lens, you would need to be 45 meters away.
If you would like to understand more about depth of field with specific lenses, use this depth of field calculator.
Does Distance Affect Depth of Field Photography?
Yes it does. Your Depth of Field photography also changes with distance. While photographing a close subject, your depth of field is smaller or narrower.
Moving farther away from a subject will make your depth of field photography wider. Moving closer to your subject will make it shallower.
The background and the foreground effectively become closer. This is when compared to the distance between you and the subject.
There is one instance where your depth of field can be manipulated. That is by using a tilt and shift lens. By playing around with the ’tilt’ of a lens, you can place an entire scene in focus when using a wide aperture.
Shallow Depth of Field Photography
A shallow depth of field comes from using a large aperture. Anything between f/1.4 and f/4 will give you a shallow depth of field photography.
This is a great way to separate your foreground from its background. The background might be uninteresting, distracting attention from your subject.
You can even use depth of field photography to single out a point of interest. This is especially helpful in an otherwise busy scene.
Medium Depth of Field Photography
With an aperture setting of f/5.6, you create images of a medium depth of field.
Here, you can make out the detail of the whole body as well as some of the background.
Where there is a ‘depth‘ to the photo, it’s important to consider the aperture setting before taking the photo. This makes the scene feel more realistic and life-like.
You’ll want to keep as much of the subject in focus as possible.
Deep Depth of Field Photography
You can create a deep or wide depth of field using a smaller aperture. Anything between f/8 and f/22 would be giving you a wide DoF.
This is how you would capture a scene where both the foreground and background are interesting.
What Happens When You Change Your Aperture
Remember the exposure triangle? If you don’t, here is a quick recap.
You enter a scene and set your camera to capture a perfect exposure. Then you need to reevaluate your settings if you decide to change your aperture.
Let’s say you are photographing at the settings ISO 100, f/16 and 1/125, and you decide you want a shallower depth of field.
You need to move your aperture from f/16 to f/2.8, which means you have added five stops of light.
You need to take this light out of your scene, otherwise, you will have an overexposed image.
The ISO is at it’s darkest, so we only have the shutter speed to play with. We need to take those five stops out, which we do by changing the shutter speed to 1/4000.
Our final settings are ISO 100, f/2.8 and 1/4000.
When to Use Depth of Field
When Should I Use Deep Depth of Field?
Consider the following two photographs. The first capture was with a wide depth of field using a wide or larger aperture, such as f/16. As you can see everything is in focus.
Both the foreground and the background have the same amount of focus, and thus, attention. The photographer wants to show you the entirety of the scene. It’s all interesting.
The mountain in the background gives a great focal point. And the crack in the foreground gives you a leading line. It all comes together.
When Should I Use a Shallow Depth of Field?
The second image is very different. Here the photographer used a shallow depth of field, using a shallow aperture such as f/1.8. Only the foreground is in focus.
This choice is down to the photographer. They obviously wanted to push the focus on the flowers in the foreground.
The background is still there. It gives a presence to the scene as you can still get a sense of where you took the image.
The blurry background doesn’t distract attention from the foreground.
What if I Have a Camera That Doesn’t Allow a Change in the Depth of Field?
Point and shoot cameras might not give you a setting that allows you to change your aperture. Similarly, they might have a fixed lens, where the focal length change comes from zooming into the scene.
There is still a way you can change and control your depth of field. By changing your setting to ‘portraits’ (human head symbol) you have access to a narrow depth of field. For wider or deeper depth of field, choose the mountain icon.
iPhones or other smartphones choose the settings automatically, stopping you from choosing a specific aperture. This is unless you use a dedicated app to control settings for a wider or narrower depth of field.
One way to create a shallower depth of field is to move closer to your subject. This change in distance will push your background into a blur, only allowing your subject in focus.
If you are a beginner with a DSLR or mirrorless camera, there are simple ways to change your depth of field with the automatic mode. By choosing the aperture priority mode, you are free to set the aperture as you wish.
The camera will then set the shutter speed and ISO accordingly.
How to Use Depth of Field for Creative Photos
Using a Wide and Shallow Depth of Field Together
One interesting way to show a scene is to find a way to use both wide and shallow depth of field photography together. This can be best done by using another photograph.
This has been a trend of late. Especially with photographers holding a historical image over the modern live version of a setting.
Or consider the photograph below.
The photographer used their mobile to capture a wide depth of field. Then they photographed the image using a shallow depth of field.
Bokeh has been a trend on its own for the last few years. It means ‘blur’ in Japanese, and photographers use it to blur the background lights.
It does add an interesting background to an image, but be careful not to overuse it.
The background can become more interesting than the foreground. This image uses a very shallow depth of field, f/1.8.
Placing the Focus on the Middle Ground
Don’t focus on the foreground or the background. Focus somewhere between instead. Your focal area should be where you want to take the viewer’s attention to.
So your focus should be on that point, no matter where it is.
As you can tell, this image is more interesting because of the shallow depth of field. It wouldn’t be as interesting if the whole scene was in focus.
Actually, the scene has a very deep or wide depth of field. You can tell because the buildings in the background are in focus. The creative blur from the bus gives the impression of a shallow depth of field.
Also, the photographer used movement to pinpoint the police officer. Not just depth of field.
Background as a Focal Point
This photographer chose the opposite, and it broke my initial viewpoint. You can use this technique to your advantage.
Turn that everyday landscape into something way more interesting. Use a creative focus through an unconventional depth of field.
What About Depth of Field in Macro Photography?
Adjusting your lens to its widest aperture accounts for the lack of light that you’ll experience. The low light environment might be severe, forcing you to raise your ISO too.
At a close distance with a wide aperture, your depth of field is going to be minute. The Canon 100 mm F/2.8 macro lens at its minimum focus distance (30 cm) will give you a depth of field of 1 cm.
Use a tripod, as your shutter speed will be too low to capture scenes without a blur.
What is Hyperfocal Distance?
The hyperfocal distance is the distance at which you focus, at a particular focal length and aperture. This is to achieve the best possible depth of field.
Depth of field extends from one-half of the hyperfocal distance to infinity.
For example, the hyperfocal distance for a 24mm lens on a Canon 5D Mark III at f/22 is 87.3 cm. If I focus the lens at that distance, depth of field will extend from 43.65 cm to infinity.
How is this useful? Let’s say you want to capture a landscape in full focus, from front to back. If you focus on the foreground, the background will appear blurry in the image. And if you focus on the background, the foreground will look out of focus.
To fix this, we need to focus somewhere in the middle, between the foreground and background. This focusing point is the hyperfocal distance.
Again, this is affected by distance. At f/2, you’ll need to place the hyperfocal distance very far away to achieve an infinite focus. For f/11, you can focus more closely.
It is also affected by the focal length of your lens. A 20 mm lens will have its hyprefocal distance just a few feet from the camera. A 200 mm lens might have its HD hundreds of feet away.
To Summarize Controlling Depth of Field
Increase Depth of Field Photography
To increase your depth of field, you have three options.
You can narrow your aperture by increasing the f-number or f-stop (f/5.6 -> f/16). By moving away from your subject, you increase your depth of field. You can also do this by shortening the focal length of your lens.
Decrease Depth of Field Photography
To decrease your depth of field, you have three options.
You can widen your aperture by decreasing the f-stop (f/16 -> f/5.6). By moving closer to your subject, you decrease your depth of field. You can also do this by lenthening the focal length of your lens.
Before you go, check out this cool video on using depth of field as a creative tool.