Keplerian telescope
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Keplerian telescope
(kep-leer -ee-ăn) The first major improvement of the Galilean telescope, developed by the German astronomer and mathematician Johannes Kepler, in which a positive (convex) lens was used as the eyepiece in place of the negative (concave) lens that Galileo used (see illustration). This gave a larger though inverted field of view and much higher magnifications.