» Nadirshots «
Spherical panoramas differ from cylindrical 360° panoramas in that they also show zenith and nadir. The term Nadir originates from the Arabic and means "footpoint". If you stand at any place on earth and look to the highest point of heaven (Zenith), your feet touch the nadir (=footpoint, i. e. the place which is exactly opposite to the zenith). In the case of a spherical panorama, this is the location where the camera tripod is normally located. Part of the art of panoramic photography is to depict the shooting location as if the camera had been floating in free space without producing a shadow. For this purpose, so-called "nadirshots" must be made in addition to the panorama shots. Ideally, they cannot be distinguished from their surroundings in the finished spherical panorama.
stairs and steps make it a bit more difficult, because here different angles lead to parallax errors