Last week I picked up the lense for my D200 finally. It's the Nikkor AF-S 18-70mm f3.5-4.5 G DX ED. Very nice lens and I'm very happy with it, but I did notice one thing. The aperature blades do not close in the exact centre of the lens, and the shape they make is a bit oval. It does take fantastic pictures, but I expected more since my 30 year old Nikkor AI 50mm f1.8 is just perfect, though admittedly the new lens is sharper. I guess just like modern vinyl pressings, some people just forgot what the word centre means, or is there a reason for this?