Depth of field
A simple and clear explanation of depth of fieldIn this lesson we will talk about depth of field (DoF). What are the factors that affect it? How to set, control and use DoF to emphasize your subject?
Take better photos with depth of field!
What is depth of field?
Check out the little cars on the right! The first (upper) photo was taken with a shallow depth of field.
The lower image has a DEEP depth of field.
The camera is able to control the depth of the area that appears sharp in your picture. And… unbelievably enough >> this is what we call depth of field. 😉
Look at the green car at the back of the photo!
On the upper picture—the one with shallow depth of field—only the red car seems sharp, while the green and the yellow are out of focus.
However, on the second photo even the green car appears sharp. The depth of field (sharpness) = DEEP.
Depth of field is influenced by three factors:
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Narrower/wider aperture
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The lens’ focal length
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Your distance from the subject
- …and indirectly by another factor too: the size of your sensor/film. But let’s skip that for now.
🙂
The following illustration can be read as a table:
The upper row shows how the three (and a half) factors above need to be set to achieve a shallow DoF.
The lower row contains the settings leading to a deep DoF.
In the following section we will discuss each factor and the effect they have on depth of field.
Scroll down!
1. Let’s start with APERTURE
Widening or narrowing your aperture will affect your photo’s depth of field.
Try moving the slider in the interactive block below and follow what happens!
The width of the green area indicates the depth of field.
Attention! This is an interactive block. Follow the instructions and the icons to see where to click! 
Uh-oh! Interactive sliders may not work perfectly on all touch screen devices. If you are having problems, please try again with a mouse! 🙂
Summary
As you move the slider from left to right, the building behind the woman will appear ever sharper and vice versa.
Take a moment to observe how narrow aperture results in DEEP depth of field, while wide aperture leads to SHALLOW depth of field.
Let’s move on!
This image has a SHALLOW depth of field
This image has a DEEP depth of field
2. Our next factor is your DISTANCE FROM THE SUBJECT
Yes, it really does have an effect on DoF! Just think about it (or see the interactive block below) >> if you take a macro photo of an insect, its eyes will appear sharp, but its body or the surface it stands on will be out of focus.
In this case your depth of field is no more than a few millimeters.
Yet when you capture a hill located 500 meters away (so, the distance between you and your subject is larger), the depth of field increases. Instead of a few inches, in certain cases it can encompass even several kilometers!
See the interactive block below for illustration!
Attention! This is an interactive block. Follow the instructions and the icons to see where to click! 🙂
Uh-oh! Interactive sliders may not work perfectly on all touch screen devices. If you are having problems, please try again with a mouse! 🙂
Summary
Compare the width of the green area to the images on the right! By subject distance we mean the distance between you and the point where your camera’s autofocus is focusing.
Conclusion: the larger the subject distance, the deeper the depth of field.
Let’s move on again!
On this photo the subject is a SHORT distance away (approx. 1 meter), which results in a SHALLOW DoF >> the background is out of focus
On this photo the subject is a LONG distance away (approx. 500 meters), which leads to a DEEP DoF
3. Finally, let’s examine the ANGLE OF VIEW
No matter what type of lens you are holding, zooming in will decrease its depth of field along with its angle of view. While on a photo shot with a wide angle lens almost everything seems sharp, shooting with a telephoto lens will yield a very shallow depth of field.
See the interactive block below for illustration!
Attention! This is an interactive block. Follow the instructions and the icons to see where to click! 🙂
Uh-oh! Interactive sliders may not work perfectly on all touch screen devices. If you are having problems, please try again with a mouse! 🙂
Summary
Follow how the green area gets narrower as you move the slider from left to right! The depth of field is considerably shallower when you use a telephoto lens. See the contrast on the following two photos:
You can control the depth of field—and what you want to accentuate or hide on your photo—by modifying any of the above three factors.
Our depth of field lesson continues with further useful information >>
Click on the button below to get to know the practical side of DoF:
You have reached the end of this lesson. Enjoy exploring our other content too! You can always pick the next lesson from the top menu!
About the author:
Bence Gyulai is a photographer and professional photography teacher. Grand Prize-winning photographer of the Hungarian Academy of Sciences, regular invited speaker at photography events, founder and host of visualgangster.com. More info & images >>
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