Assertion: eyepiece's lens | /r/ObjectUse | used for field imaging
Facets:
value: mainly
type: DEGREE
value: without spherical aberration
type: OTHER
Source sentences:
text: A mid-20th century innovation was catadioptric telescopes such as the Schmidt camera, which uses both a lens (corrector plate) and mirror as primary optical elements, mainly used for wide field imaging without spherical aberration.