Lets talk about lock on AF feature in Sony a6000 camera. This feature helpful when taking a picture of moving subject. If you are a wildlife photographer or a sport photographer this feature can help you to keep the focus on your target. and never miss a shot!
Before enable lock on AF I recommend you to put Focus mode on AF-S or AF-C. Its better you assign a shortcut key to enable lock on AF. or you can assign function menu icon for Lock on AF.