I've just taken delivery of a new (to me) D7000 (1 year guarantee from Grays of Westminster). I have two lenses: 18-70mm f3.5-4.5 and a Tamron 90mm f2.8 macro. The former needs -10 and the latter about -18 to give a sharp image at the focusing point. Is this too much, in the sense that another lens may need > -20? I might add an f2.8 telezoom at some point, but not in the immediate future so may find out too late that the body needs adjusting.