Assertion: eyepiece's lens | /r/HasProperty | big
Facets:
value: in diameter
type: OTHER
Source sentences:
text: Thus it should have a field of view as wide as possible, and that means that its front lens should be as big in diameter as possible, subject to two limits -- your budget (wide-field eyepieces are expensive), and the diameter of the focus tube of your telescope (wide lenses won't help if telescope parts get in the way).