eyepiece, ocular
(noun) combination of lenses at the viewing end of optical instruments
Source: WordNet® 3.1
eyepiece (plural eyepieces)
The lens (or combination of lenses) at the eye end of a microscope or telescope by which the image is viewed.
Source: Wiktionary
Eye"piece`, n. (Opt.)
Definition: The lens, or combination of lenses, at the eye end of a telescope or other optical instrument, through which the image formed by the mirror or object glass is viewed. Collimating eyepiece. See under Collimate.
– Negative, or Huyghenian, eyepiece, an eyepiece consisting of two plano-convex lenses with their curved surfaces turned toward the object glass, and separated from each other by about half the sum of their focal distances, the image viewed by the eye being formed between the two lenses. it was devised by Huyghens, who applied it to the telescope. Campani applied it to the microscope, whence it is sometimes called Campani's eyepiece.
– Positive eyepiece, an eyepiece consisting of two plano-convex lenses placed with their curved surfaces toward each other, and separated by a distance somewhat less than the focal distance of the one nearest eye, the image of the object viewed being beyond both lenses; -- called also, from the name of the inventor, Ramsden's eyepiece.
– terrestrial, or Erecting eyepiece, an eyepiece used in telescopes for viewing terrestrial objects, consisting of three, or usually four, lenses, so arranged as to present the image of the object viewed in an erect position.
Source: Webster’s Unabridged Dictionary 1913 Edition
12 November 2024
(noun) any of numerous plants of the genus Plantago; mostly small roadside or dooryard weeds with elliptic leaves and small spikes of very small flowers; seeds of some used medicinally
The word “coffee” entered the English language in 1582 via the Dutch “koffie,” borrowed from the Ottoman Turkish “kahve,” borrowed in turn from the Arabic “qahwah.” The Arabic word qahwah was traditionally held to refer to a type of wine.
