Why couldn't manufacturer make the camera perfect and save the trouble of consumer to fine tune the camera for the lens .. anyway Michael tapes will be releasing focustune product which the software supposed to do the calibration instead of using ruler and chart. Hope it works and not too costly.
http://www.tapestalk.com/2012/10/focustune-the-rumors-are-true.html
http://www.tapestalk.com/2012/10/focustune-the-rumors-are-true.html