I keep reading about how certain lenses acheieve their peak sharpness at certain apertures. I was wondering if: 1. I should be paying special attention to where my lenses achieve their peak sharpness? Obviously, I'd like to be able to control DOF but if this also controlls sharpness there is another factor to throw in, another compromise to be made. 2. Will I notice a big degredation in sharpness if I am not at the "peak" f-stop? 3. How important is peak sharpness generally. Kinda the same as #1. 4. My lenses are the D40 kit lens (Nikkor AF-S DX 18-55 f/3.5-5.6), as well as the 55-200 f/3.5-5.6. Does anyone know whereabouts they achieve peak sharpness? Any help would be very much appreciated.