If you’ve ever struggled to get tack-sharp photos of moving subjects, this post is for you! As a professional photographer, one of the most common challenges I see is capturing crystal-clear shots when your subject is in motion. Today, I’m going to introduce you to a game-changing technique that will solve this problem: Back Button Focus.
As a photographer who specializes in capturing candid, spontaneous moments, I love how back button focus gives me greater control over my shots. Whether I’m photographing kids, my dogs, or any fast-moving subject, I can keep my focus locked in as I wait for just the right moment. The best part? I no longer have to worry about missing the shot due to a slight shift in focus when I press the shutter.
This technique is going to be especially useful as I start taking photos of tennis players in action. With their quick movements, back button focus will allow me to track them continuously without losing that sharpness, ensuring I get clear, in-focus shots of every serve, volley, and sprint across the court.
Back button focus has saved countless photos for me, and I truly believe it’s a must-have technique for anyone serious about their photography.
Why Back Button Focus Is a Game Changer
When you first get your camera, it’s typically set up so that half-pressing the shutter button locks focus on your subject, and fully pressing it takes the photo. While this works fine for still subjects, it can cause issues with motion. Here’s why: in the milliseconds between locking focus and taking the shot, your moving subject may shift slightly, resulting in a blurry or soft photo.
The solution? Back Button Focus. This technique separates your focus from the shutter, allowing you to maintain continuous focus on a moving subject without risking those blurry results.
How Back Button Focus Works
By reprogramming your camera’s buttons, you can assign the focus function to a button on the back of the camera (usually labeled "AF-ON" or the star button). Here’s the magic: once you press and hold this button, your camera continuously tracks the subject as it moves, locking focus until you’re ready to press the shutter and capture the moment.
For example, if you're photographing a child playing, you can lock focus with the back button and follow their movements for minutes at a time. Then, when they do something cute or look up at you with a smile, you’re ready to snap that perfectly focused shot—without missing a beat.
How to Set Up Back Button Focus
Nikon Cameras:
Go to the Custom Setting Menu (the little pencil icon).
Navigate to Controls and select Assign AE-L/AF-L button (this is f4 on many models).
Set it to AF-ON to assign focusing to the back button.
In some models, you may also need to go into the Autofocus settings and change the AF Activation to AF-ON only, removing it from the shutter button.
Canon Cameras:
Open your Custom Controls Menu.
Change the shutter button’s function from Metering & AF Start to Metering Start only.
If your Canon doesn’t have an "AF-ON" button, you can assign the star button as the back button focus.
You’ll find this under Custom Controls > Shutter/AE Lock Button, and from there, select Metering Start/AF-ON.
This setup allows your camera to focus continuously as long as you hold down the back button, giving you total control over when and where to lock focus on your subject.
Got Questions?
I hope this guide has helped you get a better understanding of how back button focus works and how to set it up on your camera. If you have any questions or run into issues while adjusting your settings, feel free to drop them in the comments or reach out to me directly. I’d be happy to help you troubleshoot or walk you through the process in more detail.
Happy shooting, and I’ll see you next time with more tips to improve your photography!
— Kristina Gibb Photography