How is spherical aberration eliminated in a reflecting telescope?
A) by using the Cassegrain focus of the telescope
B) by making the primary mirror very thin
C) by grinding the primary mirror surface to a parabolic shape
D) by bending the photographic film into a concave shape

Question

Quizplus · Accepted Answer

Spherical aberration is eliminated in a reflecting telescope by grinding the primary mirror surface to a parabolic shape. This shape ensures that all incoming light rays are focused to the same point, correcting the aberration that occurs when a spherical mirror causes light rays at different distances from the center to focus at different points.

How Is Spherical Aberration Eliminated in a Reflecting Telescope