This video shows you the basics of refracting telescopes, or “refractors”, for stargazing. These telescopes collect and focus light with multi-element glass lenses at the top of the tube. They’re the best known and most commonly recognized type of telescope. Here you learn about the pros and cons of refractors. And you learn about the kinds of glass used for lenses, a factor which influences performance and cost.
Refractors are great for beginners because they’re easy to use and they don’t require optical adjustment. They’re great for daytime viewing and for lunar and planetary observing. They’re also fine for use in the city, since the high magnification of longer focal length refractors can reduce the effects of light pollution. But if you want to see faint objects like galaxies and faint nebulae, refractors are not the best choice.