Refracting telescopes dominated the nineteenth century, with the size of apertures rising to reach the physical limits for lens manufacture at a diameter of around one metre. A key optical ...

Designers of refracting telescopes figured out ... Despite myriad embellishments, however, most optical telescopes in use in the 21st century derive from the two types developed in the 17th ...

For two years, my favorite wide-field refractor has been my William Optics ... This design places the focuser within the optical tube near the center of balance, providing two major benefits.

An affordable telescope that can easily take images of the moon and sunspots on the sun thanks to a planetary camera will please some, but a flimsy build quality and a lack of optical prowess ...

Chinese scientists are working to set up the world's largest refracting telescope in Tibet Autonomous ... science and technology Lhasa Wang Junjie said construction for the optical telescope, with a 1 ...

They use glass lenses instead of mirrors, and you look through the telescope from the top. Refractor telescopes have long optical tubes as light travels in a straight line to the eyepiece. Compared to ...