Assertion: reflecting telescope's mirror | /r/HasAspect | less spherical aberration
Facets:
value: very
type: DEGREE
Source sentences:
text: In addition, mirrors have less spherical aberration, which is a scattering of light that occurs when lenses don't perfectly focus on a single point.
text: In 1721, he built a Gregorian reflector whose mirror had very little spherical aberration.