djtravels wrote:
I'd go one step further than KK suggested. Shoot in Manual, set aperture to desired DOF, shutter 1/500 or higher. Leave the ISO in AUTO. Just a thought. I haven't tried BIF in a while, and not at 600mm. Good luck
The additional things needed are spot focus and metering, setting the release to focus only, and using continuous release. Then pan through the bird, seeking to focus on the eye. The camera will fire when it achieves focus.
I use the min f-stop for the lens, which for me is 5.6. I don't mind wing tips out of focus because they will blur from motion anyway and I think it a nice effect.