I have the Nikon 260mm f10, actually 2 of them, make sure to use the metal lens hood that comes with it as the elements are quite vulerable like Sandy said. The lens is amazingly sharp corner to corner on 7x17 even wide open. Better than any lens I've ever had in this regard. The only problem is f32 is the smallest f stop you can go. I sent one of these lenses to be mounted in shutter by SK Grimes but they couldn't pull it off even though on their website they indicate they can. On some they can do this but sometimes the elements can't be removed like on mine. I really like the aperture control, very quick and easy to use and smooth as butter. I use a hat as a shutter. These lenses are really, really sharp. Emile/www.deleon-ulf.com.