Depth of field: Learn How to Take Amazing Pictures

Depth of field is one of the most important things to learn if you want to get better at being creative.

It is thanks to the depth of field that you will be able to choose to highlight your subject by isolating it more or less from the rest of the image.

If you’ve read the article on “aperture in photography,” you’ll tell me that all you have to do is open or close the diaphragm of your lens in order to affect the depth of field.

Learn How to Take Amazing Pictures
Learn How to Take Amazing Pictures

Yes, the aperture does have to do with it, but there are also other things that affect the depth of field.

In this article, we will learn what depth of field is, how it works, and how to manage it well in order to give your photos the effect you are looking for.

What is depth of field?

Depth of field is the area of sharpness that lies in front of and behind the subject that is in focus. The depth of field is based on the circle of confusion.

I will not dwell on this scientific notion, at the risk of losing you. If you want to learn more about the circle of confusion, I recommend this article: “A Basic Guide to the Circle of Confusion in Photography

Like our eyes, the camera can only focus on one spot. “What do you mean our eyes don’t focus everywhere?” Let’s do a quick two-step exercise:

Extend your arm in front of you with your thumb up. Then fix your thumb, and only your thumb. Now lower your arm and look away.

You notice that when you stare at your thumb, your eyes only see your thumb in focus, and everything else in the scene is blurry. We then say that the depth of field is shallow.

Conversely, when you lower your arm while looking into the distance, all of your vision seems clear to you. We then say that the DOF is large.

When you focus on a subject with your camera, the exact same thing happens.

Shallow vs Deep Depth of Field
Shallow vs Deep Depth of Field

How does depth of field work?

It should be noted that the PDC is determined horizontally. The area of sharpness always extends around the subject in focus: 1/3 in front of the subject, 2/3 behind. The passage from the blurred zone to the clear zone is done gradually.

How does depth of field work?

Several Factors Affect the Depth of Field

The Aperture of the Lens Diaphragm

The factor that most influences the DOF of your shots is the aperture. If you want to take landscape photos, street photos, or architectural photos, you will need to use a large depth of field. You will then have to use a small diaphragm opening (for example, f/8).

The Aperture of the Lens Diaphragm
The Aperture of the Lens Diaphragm

If you want to take a portrait, an animal photo, or a macro photo, you will need to use a low DOF to isolate your subject and prevent it from drowning in the middle of the other elements of your photo. For this, you will need to use a large aperture (e.g., f/2.8).

an animal photo
an animal photo

If you want to learn more about how aperture works, I recommend this article, “What is Aperture in Photography?”

The Distance Between the Subject and the Photographer

The distance between the subject and the photographer is also an important factor that impacts the DOF. The closer your subject is to you, the shallower the depth of field. Conversely, the further away it is, the greater the depth of field.

The Distance Between the Subject and the Photographer

Example : These two photos were taken with the same focal length and the same aperture. The only thing that differs is the distance between the subject and the photographer.

Note that the distance of your subject from the background also impacts the quality of the background DOF blur.

The closer your subject is to the background, the less the background will be affected by the DOF blur. Conversely, the further your subject is from the background, the more the latter will be affected by a shallow depth of field.

The Type of Focal Length Used

Note that the distance of your subject from the background also impacts the quality of the background depth of field blur.

The closer your subject is to the background, the less the background will be affected by the DOF blur. Conversely, the further your subject is from the background, the more the latter will be affected by a shallow depth of field.

The choice of focal length (lens) is also important when talking about the depth of field. The shorter the focal length, the greater the DOF. The longer the focal length, the shallower the depth of the field

Type of Focal Length Used

With a subject 4m away from you, a focal length of 24mm, and an aperture of f/8, the DOF zone will extend from 2.5m in front of the subject to infinity behind it.

24mm focal depth of field distance

Still with the subject 4 m from you and an aperture of f/8, but this time with a focal length of 70 mm, the DOF will be 1.6 m (0.65 m in front of the subject and 0.95 m behind him).

70mm focal depth of field distance

Still with the subject at a distance of 4m from you and an aperture of f/8, but with a focal length of 135mm, the DOF will be 41cm (19 cm in front of the subject and 21cm behind him).

135mm focal depth of field distance

The Sensor Size of Your Camera

The sensor size (Micro 4/3, APS-C, or full frame) of your body is the last factor that influences the DOF of your photos.

At a comparable focal length, the same aperture, and the same distance from the subject, the larger the sensor, the shallower the DOF. Conversely, the smaller it is, the greater the depth of field.

Sensor sizeMagnificationFocal lengthFocal equivalence
(magnification x focal length)
OpeningSubject distanceDepth of field
Full frame1300300F/810mm0,52m
APS-C Nikon1.5200300F/810mm0,79m
Micro 4/32150300F/810mm1,05m

Simulate Depth of Field Before Shooting

You have certainly noticed that your camera does not display the depth of field, neither in the optical viewfinder nor on the screen in LiveView mode. This is because when you adjust your diaphragm, it stays wide open.

Only when you trigger it does it close at the value you chose. If your diaphragm did not stay wide open before the shot, autofocus and light metering would struggle due to a lack of light from a small diaphragm opening.

If you want to preview the depth of field before shooting, the cameras have a button that is on the front of the body, near the lens. By pressing this button, the device will position the diaphragm at the value you have defined and thus allow you to visualize the depth of field.

Calculate Depth of Field

It may sometimes be necessary to calculate the depth of field. This can be useful to know the hyperfocal for example.

The hyperfocal is the minimum distance at which it is possible to focus to keep objects located at infinity with correct sharpness.

For that, you don’t need to bother with great mathematical calculations. Smartphone applications do this very well for you. I usually use “DOF Calculator”, it is easy to use and effective.

DOF Calculator
DOF Calculator

Conclusion

Now that you know the factors that affect depth of field, you’ll be able to unleash your creativity. In order to be comfortable with the notions we have just seen, do not hesitate to go out and practice on different subjects!

If you have any questions about DOF or enjoyed this article, please leave a comment.

Bryan Silveira

Bryan Silveira

Photography is a powerful medium for capturing and preserving memories, telling stories, and expressing one's creativity. The art of photography offers endless possibilities for exploring your creativity and expressing yourse