Panoramas are centered on a single point of observation, called a node. In essence, the view of 3D space from the point of observation is mapped onto a cylindrical image which surrounds the point. A QTVR panorama can represent either a full or partial horizontal view from the point of observation.
Full panoramas encompass a seamless cylinder which allows unrestricted horizontal movement.
A certain amount of vertical movement is also possible, limited only by the height of the cylinder. Partial panoramas are a subset of a full panorama as they have only a limited horizontal range of motion. The zoom angle thus represents the mapping of the cylindrical image into the viewing window on a user's monitor. As a user zooms into a panorama, the viewing window on their monitor remains the same size but shows an increasingly smaller area of the cylindrical image. The ability to zoom into the panorama can lead to a user seeing enlarged individual pixels at very small zoom angle settings.