I occasionally wish my lens would focus a little closer. I currently have the N1 with 24-85 and 70-200 lenses; they are great but not suitable for close-ups of flowers or larger insects. The Contax macro lens may be great but it is way to expensive for my budget and needs. I also think the extension tubes for the N lenses are ridiculously priced. So, I was thinking about the Nikon "T" or Canon 500 D achromat close up lenses and combine with my N70-200. Question is, can I use 67-to-62 step down ring with 62 mm Nikon close up without vignetting wide open, or should I go for 67-to-72 step up ring with 72 mm Canon 500 D to avoid vignetting? Anyone tried similar set-up? All info greatly appreciated.