 So you just want to reset the camera, not a problem. Set camera perpendicular allows you to left click on a face in order to automatically center the camera perfectly on that face. So when you click on a face, it's going to try and align itself with that face. If you say do not center, that just means that when you left click on a face, it's going to make sure that it's oriented in the same direction, but it's not going to center on it. I hope that helps and as always, I hope you have a fantastic day and I'll see you around.