Bald eagle nest

I spent yesterday afternoon on a friend's fishing boat on a lake in middle Tennesse. We anchored near a lone cypress tree with a bald eagles nest on it. It's rare to find an eagle nest so low and with a clean, non-distracting background. We couldn't get too close or else the eagles would fly to a distant perch. About an hour before sunset, we got some action. I took this shot with a 500mm f/4 Canon lens along with a 1.4x teleconverter, giving me 700mm of focal length. The image is uncrossed. I handheld the heavy lens and my very heavy 1Dx Mark II body in the boat, and this was obviously quite challenging (especially with a shoulder replacement last November). I used a fast shutter speed -- 1/3200 -- to freeze the wings as well as to mitigate the magnification of movement by the lens. I shot wide open at f/6.3 since depth of field wasn't relevant at this distance, and I prefocused on the nest. The camera was set to auto ISO, and that turned out to be 400. I was using all the focus points since the background was monochromatic.