Nikon's DX lenses may usually be overshadowed by their more expensive and higher-spec FX cousins, but the benefits in hand-me-down tech are starting to show. The company has revealed its AF-S DX NIKKOR 16-80mm f/2.8-4E ED VR, the first DX-series lens to get things like Nikon's Nano Crystal Coat, while also echoing FX-series features such as its lengthy 24.120mm focal …