Assertion: newtonian telescope | /r/HasProperty | the least expensive design
Facets:
value: for a given aperture
type: OTHER
value: generally
type: DEGREE
Source sentences:
text: It is by far the easiest to manufacture, and is thus the least expensive design and is often built by first-time amateur telescope-makers.
text: For a given aperture, Newtonian reflectors are generally the least expensive telescope because, unlike the lenses of a refractor, only one surface of a mirror needs careful figuring and polishing.