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:
“His eye had become minutely exact as to the book and its position. Then he resolved that he would not look at the book again, would not turn a glance on it unless it might be when he had made up his mind to reveal its contents.”
—Anthony Trollope (1815–1882)
“He has been described as “an innkeeper who hated his guests, a philosopher, and poet who left no written record of his thought, a despiser of women who gave all he had to one, an aristocrat, a proletarian, a pagan, an arcadian, an atheist, a lover of beauty, and, inadvertently, the stepfather of domestic science in America.””
—Administration in the State of Colo, U.S. public relief program (1935-1943)