This female photographer (Ursula) is hand holding a Sigma 50-500 at 500mm. Impressive.
Notice how good Farley, an Old English Sheepdog, is. He waits and he waits very patiently, while she takes photos of the snowy owls that migrated fron the artic to our area.
Old English Sheepdog
Before (left) and After (right)
Camera: Canon 7D ISO 400 and 1/320
Lens: Sigma 120-400 @273mm and f/9
Processed with Darktable 2.0.4: http://www.darktable.org/