PINPOINTING YOUR SUBJECT WITH AUTOFOCUS
Quality wildlife photography requires sharp focus, not just on the subject, but on the eyes of the subject. To make sure you get the focus right, you need to know how to master your autofocus system, so that you can tell the camera exactly where to focus. This requires you to choose the AUTOFOCUS MODE, and the AUTOFOCUS AREA MODE (two separate features).
AUTOFOCUS AREA MODE
Most students come to my workshop with the autofocus set to “Automatic Focus Point Selection” (the default option when you buy the camera). This lets the camera choose for you what it will focus on. Usually it will focus on the area that takes up most space in the photo. The problem with this is that if you try to focus on a bird through the branches of a tree, it will probably focus on the branches…not the bird.
By switching your AF area mode to “Single-Point”, you are telling the camera to focus on just one point. That point is usually in the centre of the frame but you can move it up, down, left and right if you need to. I prefer to keep my single point in the centre most of the time, but this brings me to the importance of also choosing the right AF mode.
Most cameras give you at least three AF modes. You have AF-S (single shot) which focuses once each time you half-press the button to focus. The focus will stay locked, unless you take your finger off the button and focus again. You also have AF-C (continuous) – also known as AI SERVO on many Canon cameras. With AF-C, when you hold the autofocus button down, the focus will keep shifting, designed to track a moving subject. Finally you have AF-A (automatic) where the camera does a little of both.
**Please note different brands use different terminology, so while you probably have these AF options, they may be called something different on your camera.
The AF Mode I use for the majority of my photography is AF-S (single shot).
COMBINING AF MODE AND AF AREA MODE
So here is how I focus for most of my wildlife photography. With my area mode set to single-point, I point the dot in the centre of the frame at the subject (if I can I will focus specifically on the eyes). Once I have focused, the focus locks in place because I am using the single-shot AF mode. So now I can recompose my photo, and as long as I keep my finger half-pressed on the button the subject will stay in focus…until I finally press the button all the way to take the photo. Using this Focus/Compose/Shoot method, I can make sure my subject is in focus, no matter where it sits in the frame of the photo.