I'm just trying to understand something here. If I want to focus on an object that's in either one of the corners of the viewfinder, is the only way to achieve sharp focus to manual focus? What I tried doing was moving my most right/left focus point on the object, auto focusing, then turning on manual focus, moving the camera up/down depending on which corner I wanted the object in and shooting. Not all the photos came out sharp though.
Is there a flaw in my method?