When it comes to photographing fast-moving subjects like birds in flight, having the right autofocus mode is critical for capturing sharp images. There are a few different autofocus modes that can work well for bird photography depending on the situation.
Single-Point Autofocus
Single-point autofocus is when you select a single autofocus point that the camera uses to achieve focus. This mode allows you to precisely pinpoint the part of the frame you want to be in sharp focus, like a bird’s eye. Since only one AF point is active, the camera can quickly lock focus on the subject. Single-point AF is ideal when you have a stationary or perched bird that is not moving around much in the frame.
Dynamic-Area Autofocus
With dynamic-area AF, you still select an initial AF point but the camera will use surrounding points if the subject moves outside of the selected point. This mode is useful for birds that are moving somewhat predictably in the frame, such as flying straight across the viewfinder. The camera can track the subject and maintain focus using the cluster of AF points.
Automatic AF-Area Mode
In automatic AF-area mode, the camera selects the autofocus points to use on its own, typically based on the closest subject. You do not choose a specific point yourself. This can be effective when photographing erratic birds in flight that move around the frame rapidly and unpredictably. The camera will attempt to track focus on the bird automatically as it moves through different AF points.
Continuous Autofocus
Continuous autofocus, or servo AF, means the camera is continually adjusting focus and tracking the subject as it moves through the frame. This is essential for maintaining focus on fast, erratic birds in flight. As the bird approaches or gets farther away, continuous AF will keep adjusting to hold focus at the proper focusing distance. It is the go-to AF mode for most action bird photography.
AI Servo Autofocus
AI Servo AF is Canon’s version of continuous autofocus. It predicts a subject’s movement and adjusts focus accordingly to maintain sharpness. This mode excels at tracking moving subjects like birds and provides a higher focusing hit rate versus single-shot AF modes. AI Servo is ideal for birds in flight as well as birds moving through dense foliage.
3D Tracking Autofocus
Nikon’s 3D tracking AF uses color metering and subject recognition to track a photographed subject across the frame. Even if the subject briefly leaves the frame and returns, 3D tracking will attempt to locate it again and restore focus. This can be highly beneficial when photographing erratic birds that may swiftly change direction or become obscured.
Back-Button Autofocus
Back-button AF separates the autofocus activation from the shutter button. You press a custom button on the back of the camera to initiate AF rather than half-pressing the shutter. This allows focus to be locked independently of the shutter button. For birds in flight, you can continuously track the subject with the custom button and only release the shutter when the moment is right.
Autofocus Cases
Some advanced autofocus systems have different “cases” you can select to customize AF behavior for different types of subjects. For example, Nikon offers AF-C Case 1 through Case 5 modes in their pro DSLRs. Case 1 is ideal for birds because it continues focusing without waiting – perfect for erratic birds that can quickly fly in and out of the frame.
Autofocus Modes Compared
Autofocus Mode | Best Uses |
---|---|
Single-Point AF | Stationary perched birds |
Dynamic-Area AF | Birds moving predictably through frame |
Automatic AF-Area | Erratic birds in flight |
AI Servo/Continuous AF | Birds in flight, birds moving through foliage |
3D Tracking | Keeping focus on erratic birds |
Back-Button AF | Separating AF activation from shutter |
Focusing Tips for Bird Photography
Here are some key tips to help you nail focus when photographing birds:
- Use continuous autofocus (AI Servo, Continuous AF) to track focus on moving birds.
- Choose a dynamic AF area mode to handle erratic motion.
- Use back-button AF to separate focusing from the shutter release.
- Select AF points clustered around where you expect the bird to be.
- Shoot in bursts to increase the chances of sharp focus as the bird moves.
- Use a tripod or monopod for stabilization if photographing perched/stationary birds.
- Prefocus on a spot where you anticipate the bird will be.
- Position an AF point over the bird’s eye to focus there.
- Set the AF tracking sensitivity appropriate for the speed of the bird.
AF System Performance
The technical capabilities of your camera’s autofocus system also impact your ability to track focus on birds effectively. Factors that affect AF performance include:
- AF points: More AF points provide greater coverage for tracking birds.
- AF point layout: Clustered points are preferable for erratic motion versus spaced-out points.
- Cross-type sensors: Cross points excel at picking up contrast to focus quickly.
- FPS shooting speed: 8-10+ fps allows more shots to capture the peak action.
- AF computer processing: A dedicated AF processor provides faster data analysis.
High-end DSLR and mirrorless cameras tend to have more advanced AF systems optimized for tracking focus on subjects like birds in flight. Prosumer or enthusiast-level cameras may struggle in this regard.
Lens Considerations
Your lens’ autofocus capabilities also impact your ability to photograph moving birds:
- AF motor: Virtually all modern lenses have internal focus motors that are fast and quiet.
- AF speed: More expensive telephotos tend to have quicker AF motors.
- Manual override: Helps fine tune focus for off-center subjects like perched birds.
- Focus range limiter: Restricts AF range to lock on birds more quickly.
- Image stabilization: Provides crucial stabilization at high focal lengths when handholding.
Pro-grade super telephoto primes designed for sports and wildlife generally offer the best blend of fast, accurate AF performance and stabilization for bird photography.
Mastering Autofocus Takes Time
Learning how to leverage your camera’s autofocus system takes practice and experience. Bird photography requires not only technical knowledge of your equipment, but also learning habits and movement patterns of your avian subjects. The more you photograph birds, the better you will get at tracking focus and capturing these swift, beautiful creatures in flight.
Conclusion
Autofocus modes like AI Servo and Continuous AF allow you to maintain tack-sharp focus on birds in flight. Choose AF area modes that can handle erratic motion for the best results. Extensive AF points, cross-type sensors, and advanced tracking combined with a super telephoto lens gives you the best chance of freezing birds in motion. Practice using the various AF modes and develop your technique over time to master bird photography. With knowledge of your equipment’s capabilities and fine-tuned field techniques, you will be ready to capture stunning bird images.