|
To answer the original question, these terms have their roots in the grinding process of newtonian mirrors. Firstly, mirrors are ground to a spherical figure, and then later figured into a parabolic shape.
An undercorrected mirror is on the spherical side of the perfect parabola, and an overcorrected one has taken the parabolising process too far.
An under or overcorrected refractor would exhibit a star test with characteristics of a newtonian with the corresponding error.
Last edited by Starkler; 17-07-2005 at 12:19 PM.
|