To maximize lens sharpness, you have to be in appropriate/reasonable distance. Consider the following photos of the footpath (less sharp) and the fence and sign (very sharp). Anything from minimum focus (9 inches) to maybe about 4-6 feet nets clear reproduction, depending on how fine the details are. Coarser details resolve very well, or at least look pleasing to me, as far away as 10-15 feet. Focus errors become more common with increasing distance even with the deep depth of field closer to infinity because the autofocus mechanism cannot segregate select forms as well as it would in short/moderate distances. Deep depth of field does not open a zone of perfect sharpness some paces away infinity; it is "merely" acceptable sharpness (though still very good). All this to say that composition really matters.
