Back to the Basics
Understanding Focus Modes in Wildlife Photography
by Jared Lloyd
For many photographers just starting out, autofocus feels like magic. You half-press the shutter, and—voilà—your subject snaps into focus. But under that simplicity lies a suite of complex decisions that determine whether your next frame is tack-sharp or tragically soft.
The core of that system? Focus Modes. Three simple acronyms —AF-S, AF-C, and MF—that unlock an entirely different kind of precision once you know how they work.
The autofocus settings we hear other wildlife photographers discussing in the field, on Facebook, YouTube, etc. have little to do with these Focus Modes. Those are called AF Area Modes (yes, it can be a little confusing) and settings such as Zone, Expanded Spot, and the various forms of subject tracking all fall under this category.
But to understand how these work, and more importantly, how and why these settings fail (even the most sophisticated autofocus systems on the market today fail just as often as they succeed), we must first understand the focus modes that drive the process. There is a reason that our cameras still have these settings built in. And working professionals routinely switch between all three.
Let’s break them down.
AF-S / One Shot: The Still-Life Sniper
The first autofocus mode—usually labeled AF-S on Nikon and Sony cameras or One Shot on Canon—is designed for stationary subjects.
When you press the shutter halfway (or your assigned focus button), the camera locks focus on your subject and holds it. It won’t try to refocus unless you release the shutter and press again. This is ideal for static subjects: birds perched on branches, bison standing in falling snow as motionless as a rock to conserve heat, or poison-dart frogs sitting on the leaf of a bromeliad. It gives you the ability to focus once and fire off as many frames per second as your heart desires, knowing the plane of focus won’t shift and each of those photos will be in-focus.
It also gives you the ability to focus and then recompose the composition.
But this focus mode comes with limits. If your subject suddenly moves—say, that same frog leaps into the air—you’re out of luck. The focus won’t follow. If you get shifty, bored, fidgety, and take a step forward or backward, the focus won't adjust with your movement. This is a sniper mode: one point of aim, no adjustments.
With this photograph of a western diamondback rattlesnake (Crotalus atrox) from the Rio Grand Valley of Texas, I used AF-S / One Shot. Because of how close I was to this subject, even at first/8, the depth of field was extremely shallow. Locking focus on the eye once allowed me to ensure the constant adjustments of AF-C / Servo focusing didn't interfere. Likewise, while this photograph was made using a Nikon D5 DSLR camera, eye-detect in more modern mirrorless cameras would have likely jumped around between scales, the eye, and the tip of the rattle. When working this close to a highly venomous species, you want to ensure all of your attention is on the snake and nothing else. Fumbling around with focusing means you are fully distracted with camera settings instead of composition and safety.
AF-C / AI Servo: The Tracker
Next comes AF-C (Continuous Autofocus), known as AI Servo on Canon bodies.
This mode is built for action. Hold down your focus button, and the camera will continuously update focus as you follow along. It’s the go-to for birds in flight, pronghorn on the run, sea turtles gliding through open water, a brown bear charging through shallow water after a sockeye salmon—any subject in motion.
AF-C transforms your camera into a tracking system. Paired with the latest in subject detection, it becomes your visual autopilot; following an eagle through a dive or a jaguar as it paces a riverbank hunting caiman.
At first glance, it would seem like using this focus mode is the obvious solution for wildlife photography. Animals move. They run, they jump, they fly. In essence, AF-C is essentially wildlife photography mode.
But it’s not always precise.
Using this Focus Mode means you give up a bit of control for responsiveness—and sometimes, that trade-off produces little more than lessons in frustration.
When we are using continuous focusing or servo, we are telling our cameras to constantly adjust that focus. When a subject is sitting still, continuous focus will make constant tweaks and adjustments that are completely unnecessary. If you have looked at a series of photos you made of a static subject, and wondered how on Earth some of them were slightly soft, it's because of those constant adjustments. In and out, in and out the focus goes, always tweaking, adjusting, attempting to re-focus.
Manual Focus: The Override
Then there’s the old standard—Manual Focus (MF).
This is where your camera steps aside entirely, and you take the wheel. You focus by hand, using the lens’s focus ring to dial in the plane of sharpness yourself. It’s the fallback when autofocus can’t do the job—when a monkey is peeking through dense foliage, when your lens keeps grabbing everything but your subject, when fog confuses the focus system.
It’s slow. It’s unforgiving. And it’s necessary.
Even with the best autofocus systems in the world, manual focus remains an essential tool in the wildlife photographer’s kit—not because it’s easy, but because sometimes it’s the only thing that works.
Do you think it's absurd to think wildlife photography ever happens in manual focus? It wasn't until the 90s that autofocus became standard in all of our cameras. And even today, every single nature documentary, every blockbuster Hollywood action film you watch, is all produced using manual focus. From the latest David Attenborough narrated documentary to the latest Marvel superhero movie - manually focused, each and every one. Why? Because if a cinematographer misses focus even for a second, the shot is ruined.
When photographing in heavy falling snow, autofocus systems tend to fall apart very quickly. On this day in Yellowstone, it seemed as though I was the only person in the national park thanks to a blizzard that would ultimately drop nearly three feet of snow in a 24-hour period of time. So heavy was the snow at times that white out situations forced me to simply hunker down until individual squalls passed. It was in one of these situations, in a total white out, that a lone bison began to materialize out of the aether. There was not an autofocus setting in my camera that would have allowed me to focus on the bison through so much falling snow. And so, I switched over to manual focus and created one of my all-time favorite compositions of a bison in winter.
Why This Matters in the Field
So why do these three modes matter?
Because wildlife doesn’t wait.
If you’re using the wrong focus mode for the situation, then chances are you’ve already missed the moment. If you find that half your photos of a great gray owl sitting atop a broken snag listening for a red-backed vole beneath the snow are out of focus, despite the situation having all of the heart stopping action of watching a rock in a field, it's because your camera is in continuous focus. And if you never learn manual focus, you’ll be helpless when your autofocus system simply gives up in challenging light or unable to bring your artistic vision to life when a shy and elusive species peers out at you through dense foliage, offering up a potential once in a lifetime opportunity to capture that moment and evoke primal emotions with your composition.
Each of these Focus Modes has the strengths and weaknesses. And understanding when to switch between these focus modes makes all the difference in the world.
The best wildlife photography happens when your camera stops being a barrier and starts becoming a conduit. Knowing when to use each mode is the difference between anticipating behavior and reacting too late. It’s the line between luck and intention.
But here’s the secret: I don’t manually switch between these autofocus modes anymore.
Not in the menu. Not in the heat of the moment. Not when an animal changes behavior mid-frame. Instead of fumbling through menu option and toggling switches between these settings, I moved my autofocus control to a different button entirely—and in doing so, unlocked the ability to use all three focusing strategies instantaneously.
Despite popular opinion, photographing birds in flight is entirely possible with manual focus. Trying to follow and track tundra swans as they flew in, backlit by the rising sun over the marsh, proved to fail just as often as it succeeded. Highlights reflecting off dead cattails in the background, made my autofocus leap around right at the pivotal moment when the swans would cup their wings and come low enough to the water for me to capture the set and setting of the morning. After a a few fly ins like this, I finally switched over to manually focusing the birds as they came. Thanks to the Electronic Viewfinders in our modern mirrorless cameras, I used Focus Peaking to ensure I knew exactly where I was focusing manually the entire time.
What’s Next
Understanding autofocus modes is essential to mastering wildlife photography. But once you understand them, you don’t have to choose between them. You can use them all—instantly, intuitively, and without ever taking your eye from the viewfinder.
In the next issue of PhotoWILD Magazine, we’ll dive into back-button focusing—what it is, how to set it up, and why it changes the way you shoot forever.
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