Assertion: eyepiece | /r/HasAspect | apparent field of view
Facets:
value: from the focal length
type: OTHER
Source sentences:
text: Aside from the focal length, each eyepiece has an apparent field of view, measured in degrees (°).
text: Eyepieces are available having apparent field of view (how large the illuminated view seems) between about 40 and 100 degrees.