Originally posted by Jacobus2 I have had the experience of standing side by side with a friend shooting birds in flight with a Canon 70-300, also using AF.S, and her gear was faster than mine at acquiring focus. Purely anecdotal I realize. I will continue to experiment with different AF modes and patterns.
I'll repeat the advice from a Canon user who posts on this forum, Dan Rentea, to practice on gulls in parking lots, etc. to develop your technique. Generally speaking, longer focal lengths require more advanced technique to get the best results and while the focus preset buttons on the DFA 150-450 will help, it takes planning and practice to make them work for you. The accelerator chip in the K-1 II apparently helps with continuous (tracking) auto-focus, but you will give up a lot of magnification by going from APS-C to FF and with smaller birds, that's not a good thing. If you are trying to capture birds in flight with continuous shooting (the K-3 has a faster frames per second rate than the K-1), you probably have no choice but to use AF.C instead of AF.S. By all reports, the DFA 150-450 is an excellent lens, but getting consistent results with birds in flight is pretty challenging with any equipment.
Or you can stick with slower birds: (taken with the manual focus SMC A 70-210)