Hummers are not a easy subject to capture, especially clearly. Another photographer there with me, at the time, had a much better camera and lense, and rapid mulit shot features and told me he had a really hard time getting clear captures also. He said they move just to fast for even his camera.
They were zooming in and out, all around us, 6 or more at a time in one area.
This is the best I could do (at least for this time :-)) and consider myself very lucky to have gotten this one.;-)