D800 service center check for the focusing points

meng235 wrote:

Understanding Camera Autofocus 's link ( http://www.cambridgeincolour.com/tutorials/camera-autofocus.htm ) is supporting your comment, specially the statement.... (Further, since the central AF sensor is almost always the most accurate, for off-center subjects it is often best to first use this sensor to achieve a focus lock (before recomposing the frame) .... but, what is the allowable tolerance here .. i.e, what is the limit beyond which we can say that there are a focusing issue @ the off center focusing sensors ? .. Thanks