Assertion: telescope's surface | /r/HasProperty | symmetrical
Facets:
value: spherically
type: DEGREE
value: nearly
type: DEGREE
Source sentences:
text: The Maksutov (also called a "Mak") is a catadioptric telescope design that combines a spherical mirror with a weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical".
text: These designs take advantage of all the surfaces being "spherically symmetrical" and were originally invented as modifications of mirror based optical systems (reflecting telescopes) to allow them to have an image plane relatively free of coma or astigmatism so they could be used as astrographic cameras.