The Astronomical Telescope The astronomical telescope makes use of two positive lenses: the objective, which forms the image of a distant object at its focal length, and the eyepiece, which acts as a simple magnifier with which to view the image formed by the objective. Its length is equal to the sum of the focal lengths of the objective and eyepiece, and its angular magnification is -fo /fe , giving an inverted image. Calculation for finite object distance

Index Lens concepts Optical instruments

HyperPhysics***** Light and Vision R Nave

Go Back

Galilean Telescope The Galilean or terrestrial telescope uses a positive objective and a negative eyepiece. It gives erect images and is shorter than the astronomical telescope with the same power. It's angular magnification is -fo/fe .	Index Lens concepts Optical instruments
HyperPhysics***** Light and Vision R Nave	Go Back