The first telescopes refracted light, and today reflectors dominate, but there is a third way to make light focus, and it ...

Designers of refracting telescopes figured out, for one, that by using two different kinds of glass together in the objective lens, they could cause the red and blue ends of the spectrum to ...

We put Starfield Optics' flagship Géar telescope — the Starfield Géar 115 Triplet APO — to the test. It did not disappoint.

It was soon realized that what was to become known as chromatic aberration was a limiting factor in refracting telescopes, and that this could be overcome by making lenses with longer focal length ...

These refracting telescopes were quite popular and often ... Ultimately mostly correct, he proved that lenses refract light to a focal point but that different wavelengths refract differently.

9.53 inch Clark Refractor The main telescope is the original 9.53 inch refractor built in 1885. The objective lens was made by Alvin Clark and Sons of Cambridge, Massachusetts, and has a focal length ...

Save £26 on a refractor telescope that, with a 90mm aperture, a 900mm focal length and a multi-coated objective lens, offers crystal clear views of the moon and planets. The Evostar 90 EQ2 ...

It features a 90mm objective lens with quality glass optics and ... Save $20 on the Celestron AstroMaster 70AZ today. This refractor telescope is perfect for beginners hoping to look at the ...

This 82mm/3.2-inch refractor is one of a kind in that ... an image of the moon by holding your smartphone's camera lens up to a telescope's eyepiece, you'll know it's a tricky maneuver.