Examples of refracting afocal systems include an ordinary Keplerian telescope, a Galilean telescope, and a lens-erecting telescope.
The Ptolemaic theory was well and truly gone, and the Keplerian version of heliocentrism was well and truly established.
This consisted of two convex lenses, in the form of telescope known as Keplerian .
Astronomical photographs of the familiar planets of our old solar system perpetrate a comfortable lie: planets are giant round spheres that follow predictable Keplerian orbits around a common yellow dwarf star.
With a sufficient number of crystal spheres and good computers, the Ptolemaic model of the solar system is as accurate as the best Keplerian models.