If face recognition fails, the phone drops to either pattern or pin lock. It actually does require multiple photos in different lighting conditions for it to work, and it does not work in low light conditions. I found that a single photo fails more often than it succeeds. Face unlock and face unlock with voice really provide minimal security as both only take samples. The following table provides an overview of the options for each section, along with my comments: Section
All the security options are under one menu, which makes configuration a lot easier.
