Telescope Shopping Tips From an Experienced Astronomer

Telescopes are popular gifts for Christmas, birthdays or other occasions ... but buyer beware! Many people live to regret their telescope purchasing decisions, either because they bought a cheap telescope that underperforms, or because they paid far too much for a telescope they rarely use. But armed with the right advice, smart shoppers can buy a good quality telescope for just a few hundred dollars.

First, whatever you do, don't buy a telescope from a department store or drug store! The telescopes you'll find there, while cheap, are typically of very low quality. They're appropriate for a child in elementary school: If the child breaks it, you're out only a modest amount of money. But if you're buying for a teenager or an adult, buy from a store that specializes in telescopes, or buy online. Good telescope brand names include Antares, Orion, Celestron, and Meade.

While there are several types of telescopes, most beginners would do well to purchase what is called a "Dobsonian" telescope. Dobsonian telescopes (or "Dobs") are relatively low-cost, yet high-quality telescopes. Generally speaking, they do not have any high-tech, computerized gadgets on them. Yet their optics are just as good as the overwhelming majority of computerized telescopes that cost thousands of dollars. Once you gain some experience using a Dob -- and should you eventually decide to make astronomy into a serious hobby -- you might one day purchase a more expensive "Schmidt-Cassegrain" or "apochromatic refracting telescope." But start with a Dob!

Astronomers compare telescopes primarily by the diameter of their main ("primary") mirrors. This is referred to as the "aperture" of the telescope. You'll want to get a Dob with an aperture of either 6 inches (150 mm), 8 inches (203 mm), or 10 inches (254 mm).

If you can afford it, purchase either an 8 or 10 inch version: The larger the diameter of the mirror, the easier it is for you to see dim objects (like galaxies and nebulae) in the night sky. Prices range from roughly $230 USD for 6-inch apertures to $500 USD for 10-inch apertures. The telescope should come with two or three eyepieces: If it doesn't, shop somewhere else. You'll use the eyepieces to control the magnification of the telescope. For example, with one eyepiece in the telescope, you can see the entire surface of the Moon. But with another eyepiece, you can zoom in on a crater.

Also, consider purchasing the following accessories:

Nightwatch: A Practical Guide to Viewing the Universe -- a really good introductory book by author Terence Dickinson;

A subscription to Astronomy magazine -- a monthly publication with beautiful photos, a guide to the night sky, product reviews, and the latest astronomy news;

Some astronomy software -- such as Name A Star Live's Virtual Planetarium™ software;

A planisphere -- Use this simple, lightweight, handheld device to identify constellations and major stars in the night sky;

An inexpensive pair of binoculars -- These are good for helping you navigate around the night sky as you search for a galaxy, nebula, or star to observe through your telescope; and

A TELRAD -- Most telescopes come with a very small telescope, called a "finderscope," mounted on top of the main telescope. As the name implies, a finderscope helps you find the astronomical object you're looking for through your main telescope. But most astronomers prefer to use a TELRAD -- a battery-powered device that projects a red bullseye in the night sky. It's much easier to aim a telescope with a TELRAD than with a finderscope.

These tools will help you learn the constellations, and otherwise help you get started in astronomy. Also, consider joining a local astronomy club where you can gain experience using various types of telescopes, and get help learning the night sky.

Happy stargazing!