I remember many years ago when I first heard about back button focus. I was curious about whether it really would up my focusing game, so I reprogrammed my Canon 7D to play around. At that time, on a DSLR, back button focus really was a game changer, particularly when photographing fast-moving subjects. Focusing was faster and more accurate, and there was no confusion when recomposing a shot.
Fast-forward to 2025 and many of us are shooting mirrorless. It’s a subtly different way of shooting than a DSLR in terms of auto focus and exposure controls. However, I still find myself using back button focus, more out of habit than anything else. So I was curious to watch this video from Adorama, where David Berman discusses the pros and cons of back button focus to see if it’s a hangover from DSLR days or if it really is still better.
What is Back Button Focus?
Traditionally on many cameras, autofocus and shutter release are combined into one button—the shutter button. Half-pressing it activates autofocus, while fully pressing it takes the photo. However, David argues that these are two distinct actions that don’t always need to be linked. Back-button focus separates these functions: autofocus is assigned to a button on the back of the camera (usually labelled AF-ON), while the shutter button is dedicated solely to taking the photo.
Why Use Back-Button Focus?
David emphasizes that back-button focus still offers unparalleled control, especially when shooting action or moving subjects. Here’s why:
- Eliminates Focus-and-Recompose Hassles: With back-button focus, you can lock focus on your subject, recompose your shot, and fire away without worrying about the camera refocusing.
- Better for Continuous Shooting: When using Servo AF (continuous autofocus), holding down the back button keeps the focus engaged, allowing you to capture sharp, in-focus shots without the delay of half-pressing the shutter.
- Prevents Accidental Refocusing: If your subject moves or if you’re shooting through obstacles like fences or crowds, back-button focus lets you lock focus and keep it there.
How to Set Up Back-Button Focus (on Canon)
Setting up back-button focus varies by camera model, but David walks through the process for Canon cameras:
- Navigate to the custom controls menu.
- Disable autofocus on the shutter button, leaving it only for metering.
- Assign autofocus to the AF-ON button on the back of the camera.
Once set up, pressing the AF-ON button activates autofocus, while the shutter button takes the photo. It’s a simple change, but it requires a little practice to get used to the new workflow.
Back-Button Focus vs. Subject Detection
Modern mirrorless cameras boast impressive subject detection capabilities, automatically tracking eyes, faces, and even vehicles. So, back to my original question: does back-button focus still matter?
David believes it does. While subject detection is fantastic for tracking moving subjects, it’s not foolproof. For instance, if you’re photographing a concert and want to focus on a keyboardist in the background rather than the lead singer in the foreground, subject detection might not get it right. Back-button focus gives you the precision to choose exactly where to focus.
Practical Tips for Using Back-Button Focus
- Go Cold Turkey: David recommends committing fully to back-button focus. Switching back and forth will only slow your progress.
- Practice in Low-Stakes Situations: Don’t try it for the first time during an important shoot. Experiment during casual outings to build muscle memory.
- Combine with Servo AF: For moving subjects, use back-button focus with Servo AF to maintain continuous focus while shooting.
- Try Dual Back-Button Focus: David programs two buttons on the back of his camera—one for subject tracking and one for a stationary focus point. This gives him even more flexibility.
When to Use Back-Button Focus
- Action Photography: Sports, concerts, and wildlife photography benefit greatly from the control back-button focus provides.
- Shooting Through Obstacles: When photographing through fences, crowds, or haze, locking focus ensures your subject stays sharp.
- Creative Compositions: If you want to place your subject off-centre, back-button focus makes it easy to focus, recompose, and shoot.
Conclusion
In the end, it does appear that David might be right: Back button focus does still have a place in the world of mirrorless cameras. I admit, I do find myself using it less that I did when shooting with DSLR’s, because that auto focus tracking is just so accurate. However, there are instances still when you will need and want to override that, and having back button focus at your disposal is a great option.
If you haven’t already tried it, give it a go and let us know what you think in the comments!
