Plossl vs Kellner Eyepieces: The Ultimate Comparison

When a beginner is choosing eyepieces on a budget, there are a number of possible designs they may choose between. While eyepieces with relatively complex, proprietary, or bespoke designs are becoming more commonly available in the beginner price bracket, there is often good reason to choose a much simpler design. Plossl and Kellner eyepieces are … Read more

Telescopes Cost: Acceptable, Good, and Really Good Telescopes

When I do public outreach, either at the Observatory, at star parties, or when doing sidewalk astronomy, a common question I get when people see my “huge!” (really mid-sized) 6” Dobsonian telescope, or my “ENORMOUS!” (really just big) 10” Dobsonian telescope, is “how much does something like that cost?” People are often shocked by the … Read more

Dobsonians vs Newtonian Telescopes: What’s the Difference?

A History of Newtonians and Dobsonians After the telescope was invented in approximately 1607 by a Dutch optician and then refined by Galileo and Kepler, there was a major issue with these early instruments. They used simple, crudely manufactured lenses and suffered from major optical defects, chiefly chromatic aberration. When a simple lens is used … Read more

Telescope Specs Explained

If you’re choosing an astronomical telescope as a beginner astronomer, you may find yourself somewhat overwhelmed. Telescopes are advertised in various different ways with different numbers and properties. Let’s take a look at what the specifications of a telescope are and what they mean. A Common Shorthand A common shorthand for telescope specifications is “Aperture/Focal-Length” … Read more