The RedCat 91 is a well-crafted astronomical imaging refractor that is easily portable, with a machined aluminum finish and ...

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 ...

The Keck telescopes are the most powerful optical telescopes on Earth ... but you can do it at Lick.” The 36-inch Great Refractor Telescope was built from 1880 to 1888. Located in the larger dome of ...

The word “Schlieren” is German, and translates roughly to “streaks”. What is streaky photography, and why might you want to use it in a project? And where did this funny term come ...

It's an early refractor telescope, and back in 1850 ... We call the actual telescope part the OTA, which means the optical tube assembly. Essentially just means "telescope." ...

Optical instruments ... Microscopes and astronomical telescopes (reflecting and refracting) and their magnifying powers. Resolving power of microscopes and astronomical telescopes.

Our guide features the best telescopes for seeing planets, tested by expert reviewers who are seasoned skywatchers. We recommend a telescope with a long focal length and a large aperture so that ...