When you photograph symmetrical subjects like domes and cathedral ceilings, to underscore the perfection of the symmetry you need to stand dead-center on the floor beneath the graphic design on the ceiling. It can be hard to judge if you are positioned exactly in the center, so look on the floor. Usually the design on the floor tells you when you are standing directly beneath the dome or some other significant element above. The center of the pattern on the floor will be precisely aligned with the center of the design above you.
This dome is in the parliament building in Budapest, Hungard. i shot this with a 14mm ultra wide angle lens.