In 1611, the German astronomer Kepler took two pieces of lenticular lens as the objective and the eyepiece, the magnification is obviously improved, later people regarded this optical system as the Kepler telescope.
In 1757, Du Grand through studying of glass and water refraction and dispersion, established the theoretical foundation of the achromatic lens, and used the crown and flint glasses manufacturing achromatic lens. Since then, achromatic Refractor Telescope completely replaced the long mirror telescope body.
At the end of the nineteenth century, along with the manufacture technology improved, making a larger caliber of the refracting telescope is possible, then there is a manufacture of large diameter Refractor Telescope climax. One of the most representative was Ekes telescope of 102 cm diameter in 1897 and Rick telescope of 91 cm diameter in 1886.
Refracting telescope has the advantages of the focal length, the plate scale is big, the tube bending is insensitive, most suitable for astronomical measurement work. But it always has a residual color, at the same time to ultraviolet, infrared radiation absorption is very powerful. While the huge optical glass pouring system is difficult, to the Yerkes telescope refracting telescope built in 1897, development has reached culminated, since this one hundred years no greater refractive telescope appeared.
Post time: Apr-02-2018