I just chanced on this thread and wonder if there is something wrong with my D5000 or with me. I got the 18-200 lens, a compromise because I work in the desert and wanted to never change lenses.
I have always wondered why my pictures were unsharp. There have been days when I thought I had a coke bottle bottom. I have borrowed more expensive lenses from a professional friend and tested mine and his with the 1952 Air Force target. The results are comparable, his are no sharper than mine. (Camera on a heavy tripod).
I read this thread twice and still don't understand how I can change the settings on my camera to make it sharper. What, exactly, did you do?