They are home to the largest refracting telescope in the world. This thing is 40 inches in diameter, so big hunks of glass that are 40 inches in diameter ground to this perfect shape that light ...

Home to the world’s largest refracting telescope, the Yerkes Observatory in Wisconsin was so influential that Albert Einstein insisted on visiting. Now you can too. Sometimes called “the ...

Refractor to reflector ... These are essentially just large telescope tubes mounted in a box-like cradle that can be swiveled around to point the telescope in any direction required.

Up front is a four-inch (102mm) diameter objective lens, which is unusually large for a refractor telescope. Most telescopes of this size and above are reflectors, using mirrors rather than lenses.

The Stellarvue 180mm f/7 APO triplet refracting telescope represents the finest large refractor available to the discriminating consumer. With limited choices for color correction available on the ...

The feat took place at Yerkes Observatory — home to the world’s largest refracting telescope. The art installation shines a light on the observatory’s past astronomical significance and its ...

Besides the views, the eighth-largest refracting telescope in North America has a deep history. “None of them is exactly the same as ours, they’re all different sizes, they’re all unique.