Many camera systems have a way to make their autofocus more sticky. Last month I had a lot of time to experiment with birds in flight in Iceland. I tried out all sorts of different settings with some interesting results. For Nikon shooters, this setting is called focus tracking with lock on and it is located in the Custom Settings Menu.
This setting has two parts; Blocked shot AF Response, and Subject Motion. First, let’s talk about subject motion. If you are panning with predictable subjects, then choose steady. If your subject is erratic and moving all over the place, then choose erratic. For almost all my shooting I have this set to steady. Generally I am panning with a bird, bear, runner or mountain biker…they are not erratic.
What is much more interesting is blocked shot AF response. This setting tells the camera how fast to try and refocus if something comes between your subject and camera. I normally leave this on 3, middle ground so the camera will try and refocus if something gets between me and my subject after a brief pause.
But here is where Iceland was interesting. We spent hours photographing puffins flying past us on a sea cliff. Literally thousands of birds to try and get a good lock on of a bird in flight. As has been described in other posts, if you can find you bird pretty far out and track it as it gets closer, autofocus does a great job staying locked on. I was using AF-C mode, Wide Area Large with bird subject detection on shooting at 20FPS. Wide-area autofocus also worked, but not as well with birds flying in front of sea cliffs and close backgrounds.
Some birds I was acquiring were much closer and faster as they flew past. All the camera brands in our workshop group were having trouble staying focused, or acquiring focus, in these situations. Just for kicks I set my blocked shot AF response to 5, the stickiest setting. And guess what. I had much better performance locking on and holding focus of close, fast moving puffins. There was nothing blocking the shot or getting between me and my subject. I just set the camera to stay locked on as much as it could, and it was noticeable how many sharp images I produced. So now I don’t think of this setting so much as a block shot AF response, but more stay focused on the bird once I get focus on it. I’ll continue to experiment with this in the future. Give it a try, and see what results you get.