EOS 5D Mark III Keeping Selected Focus Point with Back Button Focus

[bluedevil64]

I own both a 7D2 and a 5D3.  I use back button focus on both cameras.  When I change the focus point on the 7D2, I have no problem using back button focus.  However, after moving the focus point on the 5D3, pushing the back button used to focus causes the focus point to return to the center. If I return the focus to the shutter button, this problem doesn't exist.  How can I use a back button to focus on the 5D3 and keep the selected focus point?

[Waddizzle · Accepted solution]

There should be a menu setting in the AF menus of each camera that defines the Initial AF Point for AI Servo zone modes.  There are different settings that control this behavior.  It can always use a pre-defined AF point, the currently selected AF point in in 1-pt AF mode, and a couple of others.

[EDIT] In other words, the initial AF point for zone tracking can be either fixed or dynamically defined.

[bluedevil64]

I finally found the menu item and was able to make the correction.  Thanks.