Reflectors

Scottish astronomer James Gregory invented the reflecting telescope and published a description of it in 1663. Although astronomers and historians give him credit for the invention, Gregory never actually made the telescope. English mathematician Sir Isaac Newton constructed the first working reflecting telescope in 1668. It had a mirror 1.3 inches across and a tube 6 inches long. Today, every “Newtonian” reflector contains two mirrors — a large curved one called the “primary” at the bottom of the tube, and a small, flat “secondary” near the top. Light enters, travels down the tube, hits the primary, and reflects to the secondary. That mirror then reflects it to the eyepiece. Through half of the 20th century, amateurs built their own reflectors. Now manufacturers offer high-quality models, and they’re a bargain. Overall, reflectors are the least expensive telescopes, so if budget is a factor, you’ll want to look into buying a small reflector. But the biggest amateur scopes are also reflectors. So, if moving a large, heavy “light bucket” isn’t a problem, maybe a 12-inch or bigger reflector is in your future.