I have seen some photographers take photos while they are walking in a hallway or on street, etc.. where the setup is the person is walking towards the photographer, the photographer is backing backwards with the same pace to keep a constant distance and assistant is also walking with for example a softbox holding it over the person and they are I guess freezing the motion with those flash shots.
I am using Nikon system and I know some about AutoFocus Continuous mode, but it has many options like 3D-mode, Group mode, 9 focus points mode, etc... What type of focusing you select to be able to pull this off and get sharp and in focus images?
I do have a lens that has vibration reduction built in. ( 70-200mm v II )