i would firstly just like to say hello to everyone as this is the first time i have used this site. having recently got back into photography after a gap of quite a few years i took the plunge and bought a nikon d300 which im still getting to grips with. i have the 18-200 kit lens that the camera comes with and i am looking for some advice on another lens, i have looked a sigma 150-500 and nikon 80-400 and also considering a sigma 120-400. in a ideal i would buy nikon lenses but the cost can be excessive any advice would be most welcome thanks.