Here is a very old sequence taken with the A1/200-600.
In 2 years of trying I had never been able to do this with the A9 and after only a few minutes with the A1 (the 256th frame to be exact) and in rather poor light I managed to capture this sequence.
Don't believe anyone who tells you the 200-600 is too slow, it is fast and accurate.
By far the best combination is the A1/100-400 primarily because it is lighter and a little brighter. I suspect the 300 f2.8 will be the best option once it becomes available the 1.4TC at 420mm f/4 although most will find having a zoom results in better success rates.
Coming out of branches you will find the A1 struggles though. When this sea eagle launched towards me the A1 stayed focussed on the branches but eventually picked up the eagle again. The bloke with be nailed every shot with his D500/500PF
