What I meant when I said:
is that you can get the same result on a 1 by 1 sphere with different projections, as this video shows:
Here is the file of the video:
Axial vs central.blend (1.1 MB)
yet, it’s important to distinguish the central and axial projections since they behave very differently when you apply other transformations on top of it, that’s why I think we have to use the words central or axial for describing how the vectors are oriented and where they start from and spherical or cylindrical to describe what type of solid the vectors collide with. It’s the exact same terminology as used for central cylindrical and I don’t know why we shouldn’t expand it.