Assertion: telescope's diameter | /r/HasProperty | the aperture
Facets:
Source sentences:
text: ­A telescope's ability to collect light is directly related to the diameter of the lens or mirror -- the aperture -- that is used to gather light.
text: For telescopes, the optical diameter (also known as aperture) is the size of a telescope's main light-collecting lens or primary mirror, measured in millimeters or inches.
text: The diameter of the objective is referred to as the aperture; it typically ranges from a few centimetres for small spotting telescopes up to one metre for the largest refractor in existence.
text: The diameter of the lens or mirror in a telescope–the aperture–is the single most important factor for stargazing.