First of all you should check whether there is a misfocus issue with the equipment or rather a problem of handling (handshake). Download the focus test chart, mount the cam on tripod and follow the instructions given. Repeat the tests with multiple lenses to verify whether it is a lens issue or body issue. If your camera has micro AF adjustment options then use this feature to correct any focus problems. You can also search for older threads of similar topic, the question isn't new.