I used to stand on an overpass and try to follow focus as cars were driving towards me at 65 miles an hour. A developed technique required back in the day of shooting film at football games with no auto focus available. I got fairly good at it. Not easy to do as you might find out by trying this yourself. Anyway. I find that my skills have diminished somewhat but was able to follow focus this landing bird a day or so ago at a favorite lake of mine. Nikon 400 mm on a D3S. Anybody know the name of this bird. I think it might be a herron but not sure. Too lazy to research it.