Some autofocus systems will seek on strong, contrasting parallel lines oriented in certain directions, or something closer and sharper - if the sensors are center weighted, sometimes the answer is to center-aim the camera elsewhere and focus on something unobstructed, press the shutter button halfway to lock the focus and then swing the camera back to your subject. It's a bit of a PITA, but when the camera refuses to "cooperate" it can work.
With your specific zebra, I'd have tied centering the lens and focusing on the zebra's head with the oxpeckers (it seems freer of acacia branches,) hold the focus and move the camera to frame as you wish, then shoot. Basically, what
birdstrike said, in other words.
Originally Posted by wideman
I echo the thanks to
johan rebel and
JDiver for the incredibly useful information.
One thing that befuddles me is how to convince the autofocus that I want to focus on the creature in the mid-ground, and not on the grass or brush in the foreground.
Here is an example of what I'm talking about
: when I press halfway down on the shutter, the focus box/boxes appear to be on the zebra, but in fact they're focusing on the twigs in the foreground. I'm using a Panasonic FZ5, probably set to automatic shutter speed and focal length.
Suggestions, tips, etc?