I'm looking into buying a fisheye lens for my Nikon D3000 to add a creative sort of feel to certain photographs pretty much. I know about the Nikon 10.5mm Fisheye, but $600 is too expensive for me for a single lens I think. There's also this Zenitar 16mm Fisheye, but I'm not sure I want to spend $250 or so on a non-Nikon lens. I also don't want a fisheye attachment, as I hear they're absolute crap. Any recommendations for a fisheye lens for my D3000. Preferably auto-focus and under $300. Many thanks.