SUNSET: 
Choosing Your Astronomy Equipment
Optical Aberrations at the Telescope — And How to Avoid Them
Optical aberrations limit the performance of an eyepiece. Here are seven common problems, with solutions where applicable.
Telescopes: Guides & Recommendations
Common Telescope Magnification Myths
Answers to some of the most common misconceptions about telescope magnification.
Choosing Your Astronomy Equipment
How to Choose Your Telescope Magnification
How high can you get? How low can you go? The answers depend on many factors that combine to give each telescope a useful magnitude range.