So far I have a Nikon 18-75mm zoom lens and a Tamron 75-300 zoon lens. I'm wondering what, if any, other lenses should I consider buying? I'm looking for the capability to do a wide array of shots in many different enviroments. I've already decided against a "super-tele" 500mm+ for the time being. I am thinking about a fish-eye lens but I'm afraid that the novelty of the fish-eye perspective might wear off rather quickly. I'm not looking to make any purchases soon, but am rather gathering intel on what a pro-photo kit should include, lens wise. I think my next buy should be a fixed 50mm standard lens, I've heard that fixed lenses give better picture quality than zoom lenses, can anyone confirm?