This picture was taken from a river cabin at ROLF at 125 yards with 840mm f4 on a Canon 5D body. This pictures is actually 30" x 40" and is cropped and re-sized downward.
Notice the lack of head feathers on this young bird, the sparse feathering and spots on the chest. Never the less, this bird was a very successful fisherman; taking a dozen or so large crawdads, sculpins, and darters, and finally one large sunfish. I got about 175 pictures of him. Click to enlarge.