Tamron lens have ups and downs. The first I owned could not produce sharp focus. This one, recommended by a friend at National Camera Exchange, is always on the money. It's not a fast lens, f5.6. And it's slow to refocus, slow compared with the Nikon lenses I own. But it is 150-600mm with focus stabilization for $1,000. For a lot more money I would not have to be as patient on refocus (we are talking about only a second or two), and I could shoot at a lower ISO. All things considered, this lens is just fine. The bird, afternoon sun giving it a golden glow, nested near Holy Name lake in Medina. It often sits on this perch, 50 feet off a roadway. I think it's become accustomed to vehicles.