Back Button Focus: What It Is and Why You Need to Learn It
I wish I learned about back button focus much earlier. It's one of the most useful photography techniques I've learned, and I unfortunately stayed ignorant about it for way too long.
As a music and concert photographer, back button focusing is practically life-changing. It’s very popular among sports and action photographers too, but for any discipline of photography with moving subjects, it can be incredibly useful.
While employing it, the amount of photos I miss focus on has declined dramatically. Please don’t make the same mistake as me and ignore it! Take 3 minutes to give this article a glance, learn about back button focus why you should be use it. It'll be worth it.
What is back button focus and how do I use it?
The standard method to focus is to press your shutter button halfway down. When you’d like to take your photo, you press the button down the rest of the way to release the shutter.
When using back button focus, you assign another button on your camera to be the focus function, leaving your index finger with the sole responsibility of pressing the shutter button. You use your thumb on the other button you’ve assigned the focus function. By separating these functions, you can both focus and release the shutter at the same damn time.
Consider how often you lock your focus on a moving subject, only to take a shot and then immediately go back to the process of focusing because your subject moved. Back button focus lets you never skip a beat and keep shooting and focusing at the same time, while holding your focus while you snap away. You won’t understand how much time you save and the benefits of the increased control until you’re using back button focusing and experiencing it yourself.
Why is back button focusing beneficial for concerts & low-light action photography?
Focusing and shooting as fast as possible on a quickly moving subject is literally all concert photography is, so the benefit of the back button focus technique is pretty clear. You can quickly find focus on a subject, hold that focus, and release your shutter in clear, unmistakable steps.
For situations like an unexpected object entering your frame — say another band member onstage passing in front of your subject — you can use back button focus to stop focusing on the subject you wish to track until your frame is clear again. Just one of many examples where back button focusing can benefit you.
Cameras struggle in low light photography situations where your autofocus system relies on good light to lock in on a focus point. The extra control you gain by using back button focusing pays off extra in situations like these.
How to set up back button focus on your camera
Canon Cameras : Setup Back-Button Focus
- Menu > Custom Functions > C.FN III: Operation/Others > Custom Controls (#5)
- Select the Shutter button > set to “Metering Start”
- Select the AF-On button > set to “Metering and AF start”
"Hold my hand, please" instructions
- Access the cameras menu by turning it on and pressing the “menu” button.
- Switch through the menus across the top to second to last option, called the “Custom Functions” menu (the icon looks like a camera)
- Within the Custom Functions menu, select C.FN III: Operation/Others
- Within the C.FN III: Operation/Others sub-menus, look for screen #5; “Custom Controls"
- Press “Set” button to enable changes, then select the top-left option, which indicates your shutter button.
- Select the middle option, “Metering Start,” and press “Set” again to return to the buttons settings menu
- Move down one item to the “AF-On” button. Change this option to “Metering and AF start”
Nikon Cameras: Set-up Back-Button Focus
- Menu > Custom Settings > Autofocus > AF Activation > AF-On only
"Hold my hand, please" instructions
- Turn your camera on and press “menu” button
- Go to custom settings menu, which is a pencil icon
- Select option “Autofocus” to access the autofocus menu
- Select “AF activation” (should be a4 or a5)
- Select “AF-On only” option
Learning how to use back button focus
It's really simple once you have your buttons set up. Here's some photo examples of how to hold your camera to utilize both your AF-ON and shutter buttons, in case you're confused.
Pairing back button focusing with AI-Servo (or AF-C) autofocus
You may already be using Canon’s AI Servo or Nikon’s AF-C modes to focus on moving subjects, especially if you’re a concert photographer. You should pair back button focus with one of these continuous-focus modes on your camera. The benefit of this is that when you lose focus on your subject, AI-servo helps you to return focus to your subject as smoothly as possible, with minimal effort on your part.
There are situations where you may want to be in single-shot mode instead of a continuous autofocus mode like AI-Servo on Canons or AF-C on Nikons. For example, if the subject isn’t moving much on-stage and you don’t need to worry about keeping your focus on a quickly moving object, there’s no need for AI-Servo and you may find it beneficial to switch to a single-shot mode.