Another strange bug with D4, possibly D800!?!?

lock wrote:

I did not say the af on button locks the exposure. I said that if you lock the af, the camera uses that specific

area under the focus point to calculate the exposure. It does so despite changes in light in the area outside the focus point. It will continue to take into account the influence of the area you locked your focus on, until you release the af on button. After you release the af on buton, it than recalculates the exposure with the area behind the preferred focus point even if you did not actually acquire a new focus lock.