What Is Depth of Field, and How To Get Right

9 August 2021

Once you have the hang of using your digital camera on auto, it’s time to graduate to manual mode and start experimenting with key settings such as aperture, shutter speed and ISO. Together, these settings make up the “exposure triangle,” and they have a huge effect on the final look and feel of your photos. Tweaking one setting affects everything else, so getting your exposure right can be a bit of a balancing act!

Today, we’re going to talk about aperture. One of the pillars of professional photography, aperture adjusts the size of the opening at the front of your camera lens. When you do that, two things happen: your lens lets more or less light into your camera, and it changes the depth of field of your image. 


Let’s delve into how to control depth of field in your photography.


How does aperture size affect depth of field?

The aperture impacts the brightness and depth of your image. This refers to how much of your image is in focus, or how distant an item is in the image before it’s out of focus. An image with a shallow depth of field will have less of the foreground area in focus, and less of the background area in focus, which means your central point of focus will appear sharper in comparison to the foreground and background. On the other hand, an image with a deep depth of field will have much more of the image in focus, from the main focal point — such as your subject -- to the background.

As we mentioned before, adjusting the aperture will let in more or less light depending on whether you make the hole smaller or larger. To end up with a well-exposed image, you’ll need to play around with your shutter speed and ISO to match.

Next, aperture settings are presented in designated numbers known as f/stops. And here’s where it gets tricky: a smaller number, such as f1.4, is actually a larger aperture (or hole), while a larger number, like f16, is a smaller hole so it lets in less light.

What Is Depth of Field, and How To Get RightWhat Is Depth of Field, and How To Get Right

How do you control depth of field?

What Is Depth of Field, and How To Get RightWhat Is Depth of Field, and How To Get Right

Generally, you want to use a smaller number (letting in more light) when you’re shooting in darker conditions or experimenting with motion or a bokeh effect, and a larger number (letting in less light) when you need your image to be completely sharp and in focus.

The good news is, it’s fairly easy to use aperture to adjust the depth of field once you wrap your head around the f/stops.

Here’s a cheat sheet for how to decrease depth of field and how to create a shallow depth of field:

  • Larger aperture = smaller f-number = shallow depth of field (less of the image is in focus)
  • Smaller aperture = larger f-number = larger depth of field (more of the image is in focus)

Putting your newfound knowledge to use

To start with, it’s a good idea to play around with Aperture Priority mode while you’re still on auto. All you do is select the aperture, and your camera will automatically adjust the shutter speed, allowing you to experiment with different depths of field.

When you’re ready to take off the training wheels, switch to full manual mode.

    What Is Depth of Field, and How To Get RightWhat Is Depth of Field, and How To Get Right

    Once you’re in charge of the controls, you can change the aperture by twisting the physical dial around the front of your lens or on the back of the camera.

    Now, you’re probably wondering how you can use aperture and its effect on depth of field in the real world. If you look at the work of your favourite photographers, you’ll notice that while there are no set rules, certain styles of photography are more suited to different depth of field settings.

    These are some examples:

    What Is Depth of Field, and How To Get RightWhat Is Depth of Field, and How To Get Right
      • Portrait photography. In portraiture, it’s common practice for the model to be the key focal point of the image, with the photography intentionally producing a blurry background. They do this by creating a shallow depth of field.
      • Landscape photography. When trying to capture an immense landscape, photographers want as much of their image as possible to be sharp and in focus. So, they adjust their aperture to open up the scene and produce a large depth of field.
      • Wildlife photography. To isolate their subjects, wildlife photographers tend to use a larger aperture. This also works well for nighttime shoots, when it’s harder to capture the animals clearly.
      • Product photography. In most cases, product photographers stick to a smaller aperture to keep the items sharp and in focus. With this style of photography, the background is less important than capturing the detail of the products.

    Picking the right aperture for your image

    This roundup will help you choose an aperture to achieve the depth of field you’re going for.

    F-number

    Size of aperture (or opening of the lens)

    Type of background

    f1.4 to f2.8

    Large aperture

    Shallow depth of field and blurred background

    f4 to f8

    Medium aperture

    Moderate depth of field

    f11 or greater

    Small aperture

    Deep depth of field, with both background and foreground in focus


    Try your hand at different depths of field

    If you can master aperture, you’ll have more control over the final effect of your images and there’s no better feeling. 

    Shop the best DSLRs, mirrorless cameras and lenses online now, or come and see us in-person at a Ted’s Cameras store. Our experts will be happy to walk you through your options and answer any questions you have.



    Save $10*

    When you subscribe to ClubTed today!

    Learn more about ClubTed benefits