Back button focus is a game-changing way to operate your camera.
It takes some time to get used to, but it solves many of the problems you may encounter when shooting. In the video above, pro photographer and CreativeLive instructor Mike Hagen demonstrates how and why this focusing approach works.
What is back button focus?
Back button focus is a shooting technique that separates the normal function of the shutter release, focusing and shooting, into their own individual controls.
You may already be focusing just fine, but back button focus is not only about sharper shots. It is about efficiency. It helps you swap focus modes more easily and lock focus without extra steps.
Here is what you need to know about back button focus and how to set it up on your camera.
What does back button focus do?
Under a camera’s default settings, pressing the shutter release halfway will focus the shot, while pressing the release all the way will take the photograph. Back button focus separates those two functions.
The shutter release keeps the job of taking the shot, while a button on the back, often the AF-ON or AE/AF lock button, tells the camera when to use autofocus. Holding the back button continuously focuses, while pressing it once focuses and then locks the focus.
Back button focus aims to solve a few shortfalls of traditional focusing methods, including the time it takes to switch between continuous and single focus modes.
Is back button focus difficult to learn?
Back button focus is not especially difficult to learn, but it does require changing a few settings in the camera menu and getting used to shooting with two fingers. Many photographers consider it an important shift in how they work because of the control it offers.
4 Reasons to Use Back Button Focus
There are several reasons to use back button focusing, but they all come down to one big advantage: efficiency. While back button focus can help prevent focusing errors, it does not make your autofocus system inherently sharper. What it does do is help you work faster and with more control.
1. Back button focus allows you to easily swap between continuous and single autofocus
With back button autofocus, holding the button down activates continuous autofocus. When you do not need continuous focus, tapping the button once locks focus on still subjects. This means, for example, that sports photographers can shoot both the game and the sidelines without taking their eye off the viewfinder to adjust focus modes.
2. Back button focus allows you to easily lock focus
Even though many high-end cameras now offer more focus points, the center points are often still the most accurate. Many photographers use the center focus point, focus on the subject, and then recompose. With back button focus, the focus locks as soon as you take your finger off the button, so there is no need for extra steps to hold focus in place.
3. Back button focus helps prevent focus errors
Autofocus is not infallible. If an object moves into the foreground, the autofocus can easily jump to the wrong subject. Using back button focus allows you to release the button and maintain focus on your original subject more easily.
4. Back button focus makes it easy to swap between auto and manual focus
On many lenses, you do not have to flip the switch to manual focus if you are using the back button method. The autofocus stops when you release the button, so you can simply turn the lens to make manual focus adjustments. That is not possible when the shutter button also triggers autofocus.
Back button focus is all about efficiency and avoiding focus errors. It is especially useful for action photography, but it can also benefit photographers who often use focus lock or who want to make small manual focus adjustments, such as macro photographers.
How to Set Up Back Button Focus on Your Camera
Setting up back button focus will vary depending on your camera model. Even cameras from the same brand can have slightly different menu systems.
The good news is that once you understand the concept, the setup usually comes down to assigning autofocus to a rear button and turning autofocus off for the shutter release.
Although setup varies, here are some basic instructions for a few popular camera brands.
Setting Up Back Button Focus on a Nikon
Since back button focus is not the traditional way of shooting, there are a few steps to tell your camera that you no longer want autofocus on the shutter release. On a Nikon, first set the focus mode to continuous, or AF-C. This allows the back button to focus continuously when held down and to focus once when tapped.
Next, choose which rear button you want to use for focusing. On higher-end Nikon DSLRs, there is often a dedicated AF-ON button, but the AE/AF lock button can also be used. In the menu, go to Custom Settings, then Controls, and assign the AF-ON or AE/AF lock button to AF-ON.
Then return to the autofocus submenu under Custom Settings. Under AF-C Priority Selection, choose Release. This allows you to take photos even if the autofocus point is not actively on the subject, such as when you focus and then recompose.
Finally, still in the autofocus menu, go to AF Activation and select AF-ON only.
Setting Up Back Button Focus on a Canon
Canon introduced the back button focus option in 1989, and the feature is available on nearly all EOS cameras. To set it up on a Canon DSLR, locate the Custom Controls or C.Fn menu option. The wording may vary depending on the model.
Select the shutter button and AF-ON option. Under this menu, the Metering Start or Metering plus AF Start option enables back button focus and keeps metering active in automatic and semi-automatic exposure modes. The AE Lock or Metering plus AF Lock option will lock exposure on the first frame while still using back button focus.
Setting Up Back Button Focus on a Sony Mirrorless Camera
Sony mirrorless cameras, including the a7 line, also allow back button focus, but users typically need to change three settings. First, go to Custom Key Settings and assign the AEL button to AF-ON.
Next, still within Custom Key Settings, select the AF/MF button and choose AF/MF Control Toggle.
Finally, turn AF with Shutter off. Once back button focus is configured, Sony users can switch between traditional focusing and back button focus by toggling that shutter autofocus option on or off.
Back button focus takes some practice, but many photographers prefer it because of the control and efficiency it offers. By separating focusing from the shutter release, it becomes easier to switch between continuous and single focus, and even between autofocus and manual adjustments, without taking your eye away from the viewfinder.