If you want better control over exposure and background blur, learning how to set aperture on a Canon camera is one of the most useful skills you can build.
This guide explains where to find aperture settings, how Canon shooting modes affect control, and how aperture changes your photos.
What Aperture Does on a Canon Camera
Aperture is the opening inside the lens that controls how much light reaches the camera sensor.
It is measured in f-stops, such as f/1.8, f/4, f/8, and f/16.
A wider aperture uses a smaller f-number and lets in more light, while a narrower aperture uses a larger f-number and lets in less light.
On Canon cameras, aperture also affects depth of field, which determines how much of the scene appears sharp.
- Wide aperture: More light, blurrier background, shallower depth of field
- Narrow aperture: Less light, sharper background, deeper depth of field
Which Canon Shooting Mode Lets You Control Aperture?
To set aperture on a Canon camera, you usually need a mode that gives you creative exposure control.
The exact process depends on whether you use a Canon EOS DSLR, Canon mirrorless camera, or Canon compact model.
The most common modes for aperture control are:
- Av mode or Aperture Priority: You choose the aperture, and the camera selects the shutter speed.
- M mode or Manual mode: You choose both aperture and shutter speed.
- P mode or Program mode: On many Canon models, you can still adjust aperture with a control dial, but the camera manages most exposure settings.
If your camera is in Auto mode or a fully automatic scene mode, aperture may be controlled by the camera instead of you.
How to Set Aperture on a Canon Camera in Av Mode
Av mode is the easiest way to learn aperture control because it keeps the workflow simple.
You select the f-stop, and the camera adjusts shutter speed to match.
- Turn the mode dial to Av.
- Locate the main dial, Quick Control Dial, or rear control wheel, depending on the Canon model.
- Rotate the dial to change the f-number.
- Check the exposure meter in the viewfinder or on the LCD screen.
- Take a test photo and review the result.
On many Canon EOS Rebel cameras, the main dial near the shutter button changes aperture in Av mode.
On Canon mirrorless bodies such as the EOS R series, aperture is often adjusted with the control dial, touchscreen interface, or lens ring if supported.
How to Set Aperture on a Canon Camera in Manual Mode
Manual mode gives you full control over aperture and shutter speed.
This is helpful when you want consistent exposure across a series of images, such as portraits, product photography, or studio work.
- Set the mode dial to M.
- Use the camera dial to choose your aperture.
- Adjust shutter speed separately until the exposure meter looks balanced.
- Raise or lower ISO if needed for proper brightness.
Manual mode is especially useful in changing light because it prevents the camera from altering exposure settings between shots.
If you are photographing a subject against a bright background, manual control can help preserve highlights and maintain your intended look.
How Aperture Controls Background Blur
One of the main reasons photographers search for how to set aperture on a Canon camera is to create background blur.
This look is often called bokeh, although technically bokeh refers to the quality of the blur rather than the blur itself.
To blur the background more effectively, use a wider aperture such as f/1.8, f/2.8, or f/4.
A wider aperture works best when the subject is separated from the background and the lens has a longer focal length.
For sharper backgrounds, close the aperture to f/8, f/11, or f/16.
This is useful for landscapes, group photos, architecture, and documentary work.
- Portraits: f/1.8 to f/4
- Everyday snapshots: f/4 to f/8
- Landscapes: f/8 to f/16
- Macro or close-up work: Often f/8 or smaller for more depth of field
What Happens to Exposure When You Change Aperture?
Changing aperture affects exposure because it changes the amount of light entering the camera.
If you open the aperture wider, the image gets brighter.
If you stop it down, the image gets darker unless the camera compensates with shutter speed or ISO.
This is why aperture is closely connected to the exposure triangle, along with shutter speed and ISO.
On a Canon camera in Av mode, the camera usually changes shutter speed automatically to keep exposure balanced.
In Manual mode, you must adjust the other settings yourself.
Where to Find Aperture on Different Canon Camera Types
Canon camera layouts vary, but aperture control usually appears in a similar place across models.
Canon EOS Rebel DSLR cameras
Use Av or M mode, then rotate the main dial near the shutter button to change the f-stop.
Some Rebel models also use a rear dial or multi-controller for menu-based adjustments.
Canon EOS 90D, 5D, and 6D series
These Canon DSLRs often provide a top dial or rear control wheel for quick aperture changes.
In Manual mode, one dial may control aperture while another controls shutter speed.
Canon EOS R mirrorless cameras
Canon mirrorless cameras often support control rings, rear dials, touch menus, and customizable buttons.
The exact method depends on the EOS R, R6, R8, R10, or R5 model, but the principle is the same: choose Av or M and rotate the appropriate control.
Canon point-and-shoot cameras
Many compact Canon cameras offer limited aperture control, especially if they are automatic-oriented models.
If the camera supports aperture priority or manual exposure, the option is usually in the shooting mode menu.
Common Problems When Setting Aperture on Canon Cameras
If aperture will not change, the cause is often the current shooting mode.
Full Auto, Scene modes, and some automatic filters may lock exposure settings.
- Problem: Aperture number does not change
Possible cause: Camera is in Auto or Scene mode - Problem: Camera chooses a very slow shutter speed in Av mode
Possible cause: Aperture is too small for the available light - Problem: Image is too dark at a narrow aperture
Possible cause: Not enough light or ISO is too low - Problem: Background is not blurry enough
Possible cause: Aperture is not wide enough or subject is too close to background
If you are using a zoom lens, keep in mind that maximum aperture may change as you zoom.
For example, a lens listed as 18-55mm f/3.5-5.6 has a wider maximum aperture at the wide end than at the telephoto end.
Best Aperture Settings for Everyday Canon Photography
There is no single perfect aperture for every photo, but a few starting points work well for most situations.
- Portraits: Start around f/2.8 to f/5.6 for subject separation
- Street photography: Try f/5.6 to f/8 for flexibility and quick focus
- Travel photography: Use f/4 to f/8 for balanced sharpness and light
- Landscape photography: Use f/8 to f/11 for edge-to-edge detail
- Indoor low light: Use the widest aperture available, then raise ISO if needed
Lens choice matters too.
A fast prime lens such as a Canon EF 50mm f/1.8 or an RF 35mm lens can offer much wider apertures than many kit zoom lenses, making it easier to shoot in low light and isolate subjects.
How to Practice Aperture Control on a Canon Camera
The fastest way to learn aperture is to shoot the same subject at different f-stops and compare the results.
Use a stationary subject such as a chair, flower, or portrait subject, then photograph it at f/1.8, f/4, f/8, and f/16.
Watch how the background, sharpness, and shutter speed change from frame to frame.
This hands-on method helps you understand aperture faster than reading about it alone and makes Canon’s exposure controls feel much more intuitive.