Alignment Concept & Objective
It is important to understand that the camera sensor needs to be aligned exactly with the projection of the finish line vertical plane. This cannot be achieved if the mounting gear head is not centered in the exact projection (extension) of the finish line.
Only when the camera is perfectly leveled (in the swivel axis), and the alignment references along the finish line can be seen in alignment mode, will you know for sure that the camera is appropriately positioned.
The key to the process is to follow all the steps and to practice until you fully understand the procedure.