Learning how to change aperture on a Canon camera gives you direct control over exposure, background blur, and image sharpness.
The exact method depends on your Canon body, shooting mode, and whether you are using a Canon RF, EF, EF-S, or other compatible lens.
What Aperture Does on a Canon Camera
Aperture is the opening inside the lens that lets light reach the sensor.
It is measured in f-stops such as f/1.8, f/4, and f/11, and lower numbers mean a wider opening.
Changing aperture on a Canon camera affects three major things:
- Exposure: A wider aperture lets in more light, while a smaller aperture lets in less light.
- Depth of field: Wide apertures create a blurred background; narrow apertures keep more of the scene in focus.
- Lens sharpness: Many lenses perform best at mid-range apertures, often around f/5.6 to f/8.
Canon camera menus and dials make aperture control straightforward once you know which mode unlocks it.
Which Shooting Modes Let You Change Aperture?
On most Canon cameras, aperture is not directly adjustable in every mode.
The camera may automate it in Auto modes, Scene modes, or full Scene Intelligent Auto.
To manually control aperture, use one of these modes:
- Aperture Priority (Av): You choose the aperture, and the camera sets the shutter speed.
- Manual (M): You choose both aperture and shutter speed.
- Program AE (P): In some Canon models, you can shift aperture and shutter combinations, but control is more limited than Av or M.
If your goal is to learn how to change aperture on a Canon camera quickly and reliably, Aperture Priority mode is usually the best starting point.
How to Change Aperture on a Canon Camera in Av Mode
Aperture Priority mode is the most common way to set aperture on Canon EOS and mirrorless models.
It allows you to choose the f-stop while the camera automatically adjusts shutter speed for correct exposure.
Steps to change aperture in Av mode
- Turn the mode dial to Av.
- Look at the main dial or control wheel on the top or back of the camera.
- Rotate the dial to select a lower or higher f-stop.
- Check the viewfinder or LCD to confirm the new aperture value.
On many Canon DSLRs, the main dial near the shutter button changes aperture in Av mode.
On many Canon EOS R mirrorless bodies, a control dial, command dial, or rear wheel is used instead.
Some models require pressing a function button while turning a dial, especially when using a lens with electronic aperture control.
How to Change Aperture in Manual Mode
Manual mode gives full control over aperture and shutter speed, which is useful for studio work, flash photography, and difficult lighting.
On Canon cameras, aperture is usually changed with one of the control dials after selecting M on the mode dial.
Typical Manual mode workflow
- Set the mode dial to M.
- Press the shutter button halfway or wake the camera so settings display on screen or in the viewfinder.
- Rotate the main dial or rear dial to change aperture.
- Adjust shutter speed separately using the other dial.
Many Canon cameras use a dual-dial layout, where one dial controls shutter speed and another controls aperture.
If your camera has a touchscreen menu or customizable controls, you may be able to assign aperture adjustment to a preferred wheel or button.
How to Change Aperture on Canon DSLR vs Mirrorless Cameras
The core principle is the same across Canon systems, but the physical controls differ.
Understanding your camera type helps you find the right dial faster.
Canon DSLR cameras
Canon DSLR models such as the EOS Rebel series, EOS 90D, and EOS 5D series often use the top control dial near the shutter release in Av mode.
In Manual mode, the camera may use the main dial plus a rear dial or button combination.
Canon mirrorless cameras
Canon EOS R-series mirrorless cameras, including the EOS R8, R6 Mark II, R5, and R50, commonly use command dials around the body.
Some models also support the control ring on RF lenses, which can be assigned to aperture control through the camera’s custom functions.
Lens communication matters
Canon RF lenses and many EF/EF-S lenses with electronic contacts allow aperture changes through the camera body.
If you are using a fully manual lens or an adapted lens without electronic communication, aperture may need to be set directly on the lens itself.
What If You Cannot Change Aperture?
If aperture will not change on your Canon camera, the issue is usually mode-related, lens-related, or control-related.
Start by checking these common causes:
- You are in Auto or Scene mode: Switch to Av or M.
- The lens is in manual aperture mode: Some older or adapted lenses have an aperture ring.
- The lens is not electronically connected: Clean the contacts or verify compatibility.
- A custom setting changed the dial behavior: Review button and wheel assignments in the menu.
- The lens aperture is already wide open: Not all lenses offer the same f-stop range.
If the camera displays an error, try removing and remounting the lens, checking for dirt on the contacts, and powering the camera off and on again.
Canon’s official manual for your specific model is the most accurate source for control layout and compatibility details.
How Aperture Affects Photos in Real Situations
Knowing how to change aperture on a Canon camera matters because each f-stop choice serves a different creative purpose.
Here is how common aperture settings are used in practice:
- Wide aperture, such as f/1.4 to f/2.8: Ideal for portraits, low light, and isolating a subject from the background.
- Mid aperture, such as f/4 to f/8: Useful for everyday shooting, group photos, and many lens sweet spots.
- Narrow aperture, such as f/11 to f/16: Better for landscapes, architecture, and scenes where front-to-back sharpness matters.
In bright light, a wider aperture can force the camera to use a faster shutter speed.
In dim conditions, a wide aperture can help you avoid high ISO values and reduce image noise.
Useful Canon Settings to Check While Adjusting Aperture
Aperture does not work alone.
On Canon cameras, shutter speed, ISO, metering mode, and autofocus settings all influence the final exposure and look of your image.
Settings worth monitoring
- ISO: Raises or lowers sensor sensitivity.
- Shutter speed: Controls motion blur and camera shake.
- Metering mode: Determines how the camera evaluates brightness.
- Autofocus mode: Helps maintain focus accuracy when depth of field is shallow.
If you are shooting portraits with a wide aperture, use eye detection or single-point autofocus for better subject precision.
If you are shooting landscapes at small apertures, use a stable tripod and review sharpness at 100 percent magnification.
Quick Reference for Changing Aperture on Canon
If you need a fast reminder, this simple sequence works on most Canon cameras:
- Set the mode dial to Av or M.
- Use the main dial, rear wheel, or control ring.
- Rotate until the desired f-stop appears.
- Confirm exposure changes through the viewfinder or LCD.
For precise results, test a few apertures with the same scene and compare background blur, subject sharpness, and shutter speed.
That hands-on approach is the fastest way to build confidence with Canon aperture control.