The eye relief of an optical instrument (such as a telescope, a microscope, or binoculars) is the distance from the last surface of an eyepiece at which the user's eye can obtain the full viewing angle. If a viewer's eye is outside this distance, a reduced field of view will be obtained. The calculation of eye relief is complex, though generally, the higher the magnification and the larger the intended field-of-view, the shorter the eye relief.
Read more about Eye Relief: Eye Relief and Exit Pupil, Available Eye Relief, Adding Prescription Lenses
Famous quotes containing the words eye and/or relief:
“Art is a concrete and personal and rather childish thing after all—no matter what people do to graft it into science and make it sociological and psychological; it is no good at all unless it is let alone to be itself—a game of make-believe, or re-production, very exciting and delightful to people who have an ear for it or an eye for it.”
—Willa Cather (1873–1947)
“Across Parker Avenue from the fort is the Site of the Old Gallows, where 83 men “stood on nothin’, a-lookin’ up a rope.” The platform had a trap wide enought to “accommodate” 12 men, but half that number was the highest ever reached. On two occasions six miscreants were executed. There were several groups of five, some quartets and trios.”
—Administration in the State of Arka, U.S. public relief program. Arkansas: A Guide to the State (The WPA Guide to Arkansas)