How to Set Up Back Button Focus (BBF) on Canon EOS R5 for Bird Photography

Why Use Back Button Focus for Bird Photography?

Because birds are not models. They don’t pose, they don’t wait, and they certainly don’t care if your autofocus is thinking about it. Back Button Focus gives you the power to decide when to lock in. When a bird lands perfectly on that branch — lock it. When it takes off like it’s late for a meeting — track it smoothly. By moving focus to a dedicated button, you avoid the classic “oops, it refocused on that random branch” moment right as you press the shutter. It keeps your focus steady, your shots sharp, and your frustration levels low (well… lower — it’s still birding after all).Back Button Focusing gives you more control, especially for fast-moving birds. Here’s how to set it up step-by-step.

Step 1: Open the Menu

• Turn on the camera.
• Press the MENU button.

Step 2: Go to Custom Controls

• Navigate through the menus to Custom Functions.
• Select Custom Controls.

Step 3: Set the AF-ON Button

• Find and select the AF-ON button in the button list.
• Assign it to Metering and AF start.
• This will make the AF-ON button control focusing when pressed.

Step 4: Disable Focus from the Shutter Button

• Find and select the Shutter Button Half-Press option.
• Change it to Metering start only.
• This stops the shutter button from focusing when pressed. It will now only meter and take photos.

Step 5 (Recommended): Customize for Birding AF

• Still in Custom Controls, you can also assign other buttons for quick access to different AF modes.
• For birding, consider setting:
  • AF-ON button for regular autofocus (good for birds perched or predictable flight).
  • Asterisk (*) Button for Eye or Subject Tracking AF (great for birds in flight or when movement is erratic).

This gives you fast options depending on the bird’s behavior.

Step 6: Test Your Setup

• Aim at a subject.
• Press and hold the AF-ON button — focus should engage and track while you hold.
• Release the button — focus will lock.
• Press the shutter button — it will take a photo without refocusing.

Why Use BBF for Birds?

• Birds move fast and unpredictably.
• You can now lock focus instantly when needed (like when perched) or track continuously (when in flight).
• Separating focusing from shooting reduces missed shots and gives more control.