Birds in flight: focus tips for noob

[gridlock]

Yesterday I decided to try my hand at BIFs with some obliging gulls at a local nature reserve. Using a 70-200f4L on a 60D, AI Servo on back button focus (button held in), Av mode at f4, but I just can't get a shot in focus. No problem getting a sharp shot if I point the lens at a tree, so where am I going wrong? Is it my technique or am I just expecting too much from a f4 lens in thin winter sun?

Here are a couple of examples, just a straight RAW-JPEG conversion in LR3.


bif1 by griddle7, on Flickr


bif2 by griddle7, on Flickr

 

[artyman]

Well from those images they look in focus to me, the exposure is way off though and Av isn't a good choice for BIF. I set up my exposure manually, take a reading of a mid tone somewhere, grass or tarmac or just a general scene. Then just keep the bird under the selected AF point. I assume you aren't letting the camera pick the AF point. Depending on your camera model, I use centre point with assist points on my 7D

 

[gridlock]

Those two really are OOF, but on closer inspection I did have a couple well focused. My 60D doesn't have assist points unfortunately.

Next time I'll try manual and keep practicing.

 

[Oggy]

They do not look too bad for a start to me. Some settings will work better than others but I reckon the real solution is practice.