D800E firmware update
The D800E firmware update has had some effects on focusing technique. Here is my experience with this change in case it helps anyone else.
I occasionally like to use AF-S with focus priority (beep on), with focus activated only by the AF-ON button. I used to be able to press the AF-ON button, get my beep confirming focus, let go of the button to lock the focus at that point, re-compose or wait for peak action, and then release the shutter regardless of where the focus point lands.
This will no longer work with the latest firmware update. the shutter will not release if the focus point used ends up on a spot that is out of focus. Now, I have to keep holding down the AF-ON button in order to recompose/wait for a change, and get a shutter release regardless of whether the AF point used is in focus or not.
I like my beep, so this one had be going for a while. All sorted now (although I liked it better before).