I own a Letus35 Extreme and DVX and have a 20mm, 50mm, and 85mm fixed lens. I need to know what the next step is for a lens that I may need? 20mm is good for long shots, but maybe there's something where I can get a wider shot without it looking much like a fish eye lens? I want to keep price under $800 and have to get a Nikon lens (I have the Nikon-Mount).