I would like to know if any member can help/advise me on the above combination while taking moving images. I fly birds of prey for a living and take pictures for our web site and am keen to improve my techniques and quality of pictures. I have been very frustrated for some time on the best way to get a crisp sharp image while the birds are in flight. I have tried AI Focus and AI Servo with center AF and 2.8 F and find the camera or lens just cant keep up with the focussing in flight. Over 40/50 yards the birds are not that fast and yet taking 4 or 5 in a sequence can result in all being out of focus except maybe the first taken which is a long way off! The best results so far gained have been by focussing on an object and sliding the control to MF and taking a picture as hopefully the bird flies through the focal point. Any thoughts comments advice would be warmly received. Rod