How To Use Back Button Focus
Many photographers swear by it, others don’t like having to use multiple buttons to achieve focus. We are proponents of back button focus for all of our photography.
It is true that the technique will take some practice, and we strongly urge you not to use it on a trip unless you have created the muscle memory because the technique separates the focus and shutter activation between two separate buttons, allowing you to control each independently.
There are a number of benefits to back button focus, and hopefully, by the end of this section, you will be ready to give this method a try.
What is back button focus?
Once you have enabled this on your camera, back button focus will mean that half-pressing the shutter no longer has an effect in acquiring focus. All the shutter button will achieve is firing the shutter once fully depressed. Using back button focus the camera will now focus when your thumb presses a button on the back of the camera – usually the AF-On button.
This button is operated with your thumb and will quickly feel natural to you with a little bit of practice. When AF-On button is pressed, the camera will focus. You then press the shutter button to begin taking your images..
Now we know what exactly it does, let’s take a look at some of the benefits of back button focus.
The benefits of back button focus
Here are the main benefits of back button focus.
1– Photographer has complete control of focal point location and focus prior to taking the image.
2– Photographer has complete control over metering prior to taking the image.
3– Photographer has complete control over exposure triangle settings prior to taking the image.
4– The camera never guesses what the photographer wants.
The photographer has complete control over the camera & lens. When the photographer wants to focus, they press the back button. When the photographer wants to capture an image, they press the shutter button. It’s that simple.
How to set up back button focus
The following guide should help you to determine what to do, with some variations expected for certain models. If the below guides do not work for your camera model, a quick search on YouTube will likely show you a how-to guide specific to your camera make and model.
1. Nikon cameras
Open up the Autofocus custom settings menu, and scroll down to “AF Activation”. Switch this to AF-On only.
If your camera does have a dedicated AF-On button, you will also need to complete another step. Open the Controls custom settings menu and go to the “Assign AE-L/AF-L Button” option – choose “AF-On”.
Set the camera’s AF dial to AF-C.
2. Canon cameras
Open up your camera’s quick settings, and select the button as shown below. You should then see the menu on the right. First, set the function of the “Shutter button half-press” to “Metering start”.
Next, choose the AF-On symbol and set that function to “Metering and AF Start”. Many Canon cameras are already set to this by default, but it is worth checking. Finally, set your camera to AI Servo mode.
3. Sony cameras
Open your Custom Settings. Find AF w/Shutter and turn this to OFF. Next, set the AE-L Button to AF On. Ensure your camera is in continuous focus mode.