I spent the night learning about autofocus, and discovered that some DSLR cameras have the ability to store micro-calibrations for individual lenses.
You can download charts or use images on screen, and in this shot you can see there is a clear difference in the focus at a point 40 mm infront and 40 mm behind the focal point.
I am trying different tests before making any changes, but it seems that my kit lens needs to be altered.
