Camera Smart: Mastering Custom Buttons
How Wildlife Photographers Can Gain Total Control in the Field
So it’s the start of a new blog series, and this one is focussed on the technical end of things, namely getting the most from your camera gear. This series will be a monthly drop, (or occasionally more often if I find something that get me fired up) and I’m not going to cover the theoretical side of photography, this is more of a practical, try this/it works for me kind of blog that I hope you’ll find useful.
There are times when speed and precision matters. A split-second delay in switching focus modes or changing exposure could mean the difference between capturing a once-in-a-lifetime shot—or missing it entirely, and after months of dedicated field work and long hours making sure your shooting in the most ethical way possible, the last thing you need is to miss the shot due to a fumble. That’s where one of the most underused tools on your camera comes in: custom buttons.
Many mid-range and professional DSLRs and mirrorless cameras offer an array of configurable controls, but these are often overlooked. In this article, we’ll explore why wildlife photographers should be taking full advantage of customisable buttons and custom shooting setups to streamline their workflow, avoid digging through menus, and react instinctively to fleeting moments. We’ll cover how to do this on Canon and Nikon systems, including practical examples from the field.
Why Custom Buttons Matter in Wildlife Photography
Wildlife photography is unpredictable. You may be tracking a static fox in morning mist one moment, and suddenly a red kite dives into frame from above. The ability to instantly switch focus methods, adjust exposure, or toggle drive modes without lifting your eye from the viewfinder is critical.
Customisable buttons let you assign key functions—like switching from One Shot to Servo AF, toggling between metering modes, or activating back-button focus—to dedicated physical controls. This removes friction, improves your reaction time, and helps you operate the camera by feel rather than by thought.
Let’s look at a few core advantages:
Speed: React to fast-moving wildlife without entering menus
Efficiency: Custom setups reduce mental overhead during high-pressure moments
Focus: Stay immersed in the scene with less camera fiddling
Control: Tailor the camera to your style of shooting and subject behaviour
Canon and Nikon: What’s Customisable?
Most mid-range to professional Canon and Nikon bodies—like the Canon EOS 90D, R5, R6, Nikon D7500, D500, and Z6/Z9—offer custom control options. While the level of granularity varies, both systems allow for reassigning buttons like:
AF-ON
AE-L / AF-L
Fn1 / Fn2 (Nikon)
SET / M-Fn / DOF Preview (Canon)
Joystick or Multi-controller
Lens buttons (on supported L or Z lenses)
Let’s break down how to customise buttons in both ecosystems, and what those buttons can do for you.
Customising Buttons on Canon Cameras
How to Do It (Canon)
Go to the Menu
Navigate to Custom Functions (C.Fn) or Custom Controls (location varies slightly between DSLR and mirrorless).Select “Custom Controls”
You’ll see a camera diagram showing assignable buttons.Select a Button to Change
Tap or scroll to select a button like AF-ON, SET, or M-Fn.Assign a Function
Options include:AF-ON / Eye Detection Toggle
Switch AF Area / Focus Mode
Exposure compensation
Toggle ISO or metering mode
Movie record
Call up custom shooting mode (C1–C3)
Canon in the Field: Real-World Example
Let’s say you’re photographing a heron hunting along a riverbank with the Canon EOS R5. You’re using Animal Eye AF to track it. Suddenly, it takes off into flight, moving rapidly. Eye detection loses it in the reeds, and you need to quickly switch to Zone AF or Servo AF to keep up.
If you’ve set the M-Fn button to switch between AF area modes, or used back-button focus with a different AF mode assigned, you can make this switch mid-frame—without taking your eye off the bird or leaving the EVF. If your AF-ON button is set to Servo with Animal Eye, and AE-L is set to Zone AF, you can switch between them simply by pressing a different button with your thumb.
Likewise, you could assign the SET button to ISO control and adjust sensitivity as the light changes—all while tracking movement in real time.
Customising Buttons on Nikon Cameras
How to Do It (Nikon)
Go to Menu > Custom Settings (Pencil Icon)
On most models, look under section f: Controls.Select “f1: Custom Control Assignment”
Choose the Button You Want to Change
Options may include:Fn1 / Fn2
Pv (Depth of Field preview)
AE-L / AF-L
OK Button (in playback or shooting)
Sub-selector (joystick)
Assign a Function
Common assignments include:AF-area mode
AF-On
Exposure Delay Mode
Spot metering
Playback zoom 100% (OK button)
Nikon in the Field: Real-World Example
Let’s imagine you’re tracking a stoat in winter camouflage, darting across snowy heather with the Nikon D500 and a 300mm lens. You’re shooting in Group-Area AF, but it’s small, fast, and unpredictable.
You’ve assigned:
Fn1 = Switch AF-area mode
Fn2 = AF-On (back button focus)
Pv button = Spot metering
OK button = 100% playback zoom on centre point
You’re tracking the stoat in Group AF, but as it pauses briefly, you tap Fn1 to drop to Single-Point AF and focus on the eye. As it bolts again, another press returns you to Group-Area AF. If the lighting shifts and snow begins to brighten the scene, Pv toggles spot metering to ensure you meter for the animal, not the background.
After the action, a quick press of the OK button zooms to check sharpness on the eye—no fiddling with dials.
Using Custom Shooting Modes (Canon: C1–C3 | Nikon: U1–U2)
Another underrated tool is custom shooting mode presets. These allow you to save a full camera configuration (shutter speed, aperture, ISO, drive mode, AF settings, metering, etc.) and switch to it instantly via the mode dial.
Use Cases
C1 / U1: Fast-moving birds in flight
Servo AF
High-speed burst
Zone AF
Auto ISO with 1/2000s minimum shutter
C2 / U2: Mammals at dusk
Single AF
Silent shutter
Manual ISO and aperture
Spot metering
Switching between these pre-saved setups allows you to adapt instantly to changing conditions or subjects, without touching multiple dials and settings.
On Canon you can also assign custom shooting modes to a single button, so I have my R6 set up with hot button for birds in flight. This changes my settings to 1/2000 at F9, with +1 Exposure compensation, knowing that normally I have my camera set at around 1/1000 and F9, with exposure dialled in a little on the darkside. I can now happily photograph ground subjects, and if a bird takes off from a perch or a bird of interest flies over I can just hot and hold my hot button and snap away with reasonable “average” settings for birds in flight. When the bird has gone I release the button and my camera reverts back to my usual “ground” focussed 1/1000, F9, under exposed by 1/3 of a stop.
The Role of Lens Buttons
Many telephoto lenses—especially Canon L-series and Nikon Z/Super-Telephoto primes—have AF stop or function buttons on the lens barrel. These can be customised too.
Common Lens Button Assignments
Hold current AF setting (AF stop)
Switch between two AF area modes
Toggle Eye AF on/off
Jump to a focus preset (if available)
If you’re handholding a Canon RF 100–500mm or a Nikon Z 400mm f/2.8, the lens button can allow you to momentarily override AF or toggle metering, all with your left hand—keeping the right free for shutter and camera controls.
Some lenses (for example the Canon RF 200-800mm) also have a control ring built into them that is also customisable, and I use this to quickly under or overexposure a shot, for example if I am shooting Otters and suddenly the lighting changes and highlights on water ripples start to blow out, I can just dial back a stop or 2 manually without taking my hand off the lens.
Final Thoughts: Build Muscle Memory, Not Menu Memory
Custom buttons are about building muscle memory. The more you can keep your focus on the subject, not your gear, the better your photos will be. Whether you shoot with Canon or Nikon, DSLR or mirrorless, investing time in configuring your camera to suit your real-world needs pays off.
To get started:
Review your most-used functions in the field (AF area, metering, ISO, etc.)
Decide which ones you want instant access to
Assign those to buttons that fall naturally under your fingers
Practice in low-stakes conditions before heading into the wild
With a bit of setup, your camera will feel like an extension of your eyes and hands—letting you react faster, shoot cleaner, and stay immersed in the natural world.