Most of us are not aware of the back button focusing feature on our cameras and how it can be a game changer in every photographer’s life. Since most photographers including novices are used to focusing by pressing the shutter-release button halfway, back-button focusing can take some getting used to and once you get the hang of it, there’s no going back.
Back button focusing is an excellent feature that will help photographers get sharp images without losing focus on the subject before releasing the shutter as it helps you lock focus. In this article, we will look at how to set the back button to focus on Canon cameras.
So What is Back Button Focus?
Back button focusing is nothing but using the button on the back of your camera to control focus. You remove the autofocus function from the shutter button and assign it to another button on the back of your camera.
Let’s first look at the difference between default focusing and back button focusing.
The Difference Between Default Focusing and Back Button Focusing:
Built-in Focusing:
When using the camera’s default settings, you accomplish two tasks using the shutter-release button.
- You press the shutter button halfway to focus the shot and meter the scene.
- You then press it all the way down to release the shutter, i.e. to take the photo.
Back Button Focusing:
With back button focus, two tasks are completed using two different buttons. This separates focusing from the shutter button.
- The button on the back of your camera is set to focus on your subject. This is usually the AF-ON or AE Lock button. Pressing this button will focus on your subject and when you release your finger from the button, the focus will lock.
- You then use the shutter-release button to take the photo.
If you don’t press the back button to focus, the camera behaves as if you had manual focus set so you can focus and shoot manually.
Why Use Back Button Focusing?
Back button focusing allows you to have more control over focusing and the different focusing modes.
- You can easily lock focus:
In the default focusing method, with each press of the shutter button, your camera refocuses, but with back-button focusing, the camera focuses only when the button is pressed again, not when the shutter-release button is pressed. This gives you control over whether to refocus or not.
- This allows for easy focus and recomposition:
If you want accurate focus on areas that are outside the area of AF points, with the default focusing method you will need to focus and recompose for each shot because each time you press the shutter button the camera focuses again. But with back button focusing you can simply focus, recompose once and shoot as many times as possible without recomposing in focus because with back button focus your focus is locked at the moment you release the back button after focusing on a point as long as the camera and/or subject is not moving. This way you have more control over your composition.
- Easy switch between single and continuous focus:
Also, as long as you keep the back button pressed, the camera will continue to focus on the subject you have focused on, thus continuing tracking focus without the need to switch to tracking focus. When you don’t want to focus continuously, you can simply focus once by pressing the back button and focus will lock on your stationary subject.
- Helps prevent focus problems:
Using the back button focus, once the focus is locked on your subject, if a subject enters or an object is between the camera and the subject you are focusing on, the focus will not change.
Having your subject pre-focused using the back button focus allows you the freedom to shoot at the decisive moment. You don’t have to worry about focusing and shooting, but you’d rather shoot as the moment happens without worrying about focusing and occasionally missing a shot.
Situations Where You Should Use Back Button Focusing
There are a few scenarios where focusing the back button works well compared to the default focusing process.
- When taking photos of children and sports, fast-moving subjects perform better with the focus back button engaged thereby minimizing the time between focus and shutter release. This also helps with continuous shooting when the subject is moving and normal shooting when the subject is not moving.
- When shooting portraits, if your subject stays still with only slight changes in pose, you can establish proper focus on your subject and shoot as much as you want without having to worry about focusing every time.
- The back button focus allows you to precisely focus on the minute area and then not lose focus when an object is between the camera and subject.
How to Set Back Focus Button on Canon Camera:
Back button focus settings vary between camera manufacturers and between camera models from the same manufacturer. The best advice is to read your camera’s manual as it will have specific instructions for your camera model. This feature is available to set on most Canon camera models.
General Instructions For Setting Back Focus Button On Canon Cameras Are:
1. Change the AF mode to AI Servo mode.
2. You then need to find “Custom Controls” or the “C.Fn” option in the menu. This function may vary slightly for each camera model.
3. Within the custom control menu, you need to reassign the functions for the shutter button and back button. You must first remove the AF activation option from the shutter-release button. To do so, you must select the “Shutter button/Metering and Start AF” option and change it to the “Measurement Start” option.
This is how it looks once the custom settings menu is set.
4. Then you have to set the AF-ON button to “Metering + AF Start” – this will enable the Back Button Focus option.
What If Your Camera Doesn’t Have an AF-ON Button?
Don’t worry if you don’t have a dedicated AF ON button.
If you don’t have an AF-ON button, use the AE Lock button to refocus the button.
What Are the Advantages of Using the Back Button Focusing Method?
- The first advantage is that focusing back button allows you to easily lock focus with the press of a button. With the default focusing method, a photographer may have to perform focus recomposition when you need to keep elements in focus outside of the autofocus point area and for each shot, you have to focus and recompose. With back-button focusing, because the focus is locked, you don’t have to worry about using buttons or methods to maintain focus on your subject again.
- Continuing focus lock using the back button as discussed above, the advantage is that, if something else enters the frame before releasing the shutter, you won’t lose focus on your subject.
- When using the back button focusing, it’s easy to switch between single and continuous autofocus modes. This can be advantageous for photographers shooting wildlife, weddings, and sports when they need to switch between continuous and single autofocus, and it can be done with a simple press of the back button without having to take their eyes off the viewfinder.
- When the back button is pressed, the camera is in continuous focus mode, which allows you to continue to maintain focus on the subject and allows you to continue shooting as long as the back button is kept pressed. Once you release the back button, the focus point is locked on your subject so you can use the camera in single autofocus mode as long as your subject is not moving. If your subject moves, focus on your subject again by pressing the back button and lock focus by releasing the back button.
- The back button focusing also helps photographers easily switch between auto and manual focus modes. If you are using a lens that does not require you to turn on/off the manual focus function (which many lenses do with a feature called full-time manual focus), then, when using the back button focusing function , when you release the back button, the autofocus function stops, allowing you to manually turn the focus ring on the lens to focus manually.
In general, using the back button focusing helps the photographer avoid losing focus on the subject. That way, focusing errors can be minimized.
Further Resources:
- 15 Things You Should Know Before Pressing the Shutter Button to Take a Photo
- 6 Reasons Why Your Pictures Are Out of Focus
- Bite Size Tips: How To Get Your Nails In Focus Every Time
- Get to Know Your Camera’s Buttons & Dials Easily
- Get Sharp Images Now – Use Your Camera’s Focus Tool
- How to Successfully Focus on Fast-Moving Subjects