It's the Nikon 50mm f/1.8 prime lens. It retails now at $100-$200 ... On the river, this translated to photos of anglers showing off their catch, hook-sets, anglers in midfight, or just hanging ...

Central sharpness is very good at f/1.8 and f/2, excellent from f/2.8 through to f/5.6, very good from f/8 to f/16 and fair at f/22. The edges are good at f/1.8 and f/2, very good from f/2.8 to f ...