Facts And Questions:
These Facts and Questions pages mainly tell you how to use the Aberrator-interface and also explain the nature of the aberrations.

Click on the Aberrations and Manual items on the left-frame to learn more on the usage of the Aberrator.

Dictionary (still under construction)
Airy disc: the brightest spot of light when you look at a star in focus. This disc can contain a maximum of 84% of all the light that arrives from a star (perfect refractor telescope).

MCT: Maksutov-Cassegrain telescope. A closed-tube mirror-telescope with a secondary obstruction. Less common than the SCT, this telescope uses a corrector (real glass).

SCT: Schmidt-Cassegrain telescope. A closed-tube mirror-telescope with a secondary obstruction. A very popular type of telescope due to the portable size. As the MCT this one also uses a corrector but they are thin and often made of flint-glass.