Astronomy can be a potentially frustrating hobby without the right equipment. While many people start off doing binocular or naked eye astronomy, eventually they want to move up to the realm of the telescope. Choosing the right one may determine whether you spend starry nights indoors or out. A poor quality telescope can kill even the most enthusiastic observer's interest in amateur astronomy. Here, we'll give you some tips on how and what to buy.

The telescope has come a long way since the days of Messier the Comet Hunter. While the objects in his famous Messier catalog were mere "fuzzies" through his eyepiece, today everyone can experience firsthand their amazing diversity and splendor. With a low cost telescope, you can see the rings of Saturn, the Eye of Jupiter, as well as dozens of galaxies, clusters, and nebulae. Now, more than any other time in history, amateur astronomers have access to more high quality, low cost equipment to bring the heavens down to earth.

Of course, with all these choices it's easy to get confused. Most of the time, telescopes are marketed the wrong way (in department or hobby stores, home shopping, and other "general" markets). The only thing the ads talk about is the telescope's magnification. (420x!!! for example.) This is a useless number. Why? First of all, a telescope is only good for about 50x magnification per inch of aperture. e.g. a 3 inch telescope will magnify objects about 150 times. Second, most of the time you spend looking (at the sky) through a telescope, you will be using low magnification or "low power". Low power provides a wide angle view of the sky. Typically, the average low power field of an amateur instrument is 1 1/2 to 2 times the diameter of the full moon. You want a wide field to locate objects quickly, and also to fit the entire object in the field. (Many objects are larger in apparent size than the full moon.) In addtion, low power provides better contrast: i.e. objects are brighter and easier to see. High power is useful to study detail in an object, to split a double star, and to zoom in on the moon and planets. But the amount of magnification you can use is limited by the atmosphere. "Seeing" is the astronomical term for the clarity and transparency of the sky. If the air is turbulent or very moist, it will blur the image (just think of "Twinkle Twinkle Little Star"). When this happens even the highest quality telescopes cannot see clearly.

Okay, so we've learned that magnification is not important when shopping for a telescope. So what should you look for? We've broken the important points down into 3 categories:

Quality, Aperture, and Application.

By Quality, we mean the optical system (lenses and mirrors), accessories (eyepieces, finderscope), and the mount. You don't always get what you pay for. My (Chris) first telescope (which was an "off-brand" and shall remain nameless) cost $300 and was an absolute piece of junk. A telescope with the exact same specs and price (made by one of the companies listed below) outperformed it a hundredfold. The most important thing to consider here is the brand name. We recommend all these brands (in no particular order): Meade, Celestron, Orion, and TeleVue, and we've provided links to all their websites. With these brands, you can be reasonably certain you're getting a quailty instrument, whether you buy from the low or high end. The lenses and mirrors will be maunfactured to more exacting specifications, because optics are these companies bread and butter. The same is true for accessories. A telescope is only as good as its eyepiece. A high quality telescope is reduced to mediocre if you use a poor quality eyepiece with it. Finally, the mount of a telescope is essential. Is it sturdy? Will it last? Can you figure out how it works in a reasonable amount of time? These are some of the questions to ask when looking at the mount. Do you want a complex (i.e. equatorial) mount or a simple one (alt/az)? Wood or aluminum? Generally, aluminum tripods are sturdier and last longer, but are also more expensive. Equatorial and alt/az mounts are explained in the telescope designs page.

By Aperture, we mean the diameter of the primary lens or mirror. Simply put, the more aperture you have, the more you can see. For example, a 10 inch reflector has 56% more light gathering power than an 8 inch. If you compare side by side views of the same object, it will be bigger and brighter in the 10 inch, but not dramatically so. The 56% is a little deceiving. For most amateurs, anything 10 inches and under will do the job. Another aspect to consider here is the focal ratio, written as f/8, for example. When you read about telescopes in ads, the two most common numbers mentioned are the aperture and f/ratio. (4.5 inch f/6 reflector,  for example). Telescopes with low f/ratios are called "fast" (f/6 and lower). This means they have a wider field of view with any given eyepiece, and objects appear brighter in fast telescopes. With a Schmidt-Cassegrain telescope, it's actually possible to change the focal ratio using a focal reducer. Why would you want to do this? Make it "fast" for viewing faint galaxies and nebulae, and make it "slow", or long, for viewing the moon and planets. Traditionally, telescopes with long focal lengths were better for viewing the moon and planets, but this is not necessarily true anymore. However, if lunar and planetary observing is your primary goal, you might want to consider a long focal length telescope.

By Application, we mean what you're going to use it for. Observing, photography, or both? Will there be young'uns pulling and swinging on it? Figuring out exactly what you want a telescope to do for you is critical. Just as you wouldn't buy a Porsche to drive off-road, you wouldn't buy a Dobsonian to do astrophotography. Below, we'll list the four main types of telescopes in use by amateurs today and give the advantages and disadvantages of each, and we'll rate them in five categories: Cost and Value: 1 star is least affordable, 5 stars most;  Photography: taking both deep sky and lunar/planetary photography into account; Deep Sky: for observing deep sky objects; Lunar/Planetary: for observing the moon, planets and double stars; Ease of Use: easy (5 stars) or hard (1) to set up and use.

Okay, maybe you have some idea what you want- now, where do you get it? For the amateur astronomer, there are many more choices through mail order and the 'net than at a retail store. If you want to go local, try the "nature" stores in the mall; sometimes they have a decent selection of one of the companies mentioned above. The other option is camera shops. That's pretty much it, unless by some miracle you look under telescopes in the yellow pages and find something! 90% of our astronomical equipment was purchased through mail order. Some of the companies we recommend ship directly; others go through dealers. Listings of dealers can be found on their websites and also in astronomy magazines. If a dealer is not "authorized" by a particular company, be careful, as you should when shopping by mail for anything. Another good place to look on the 'net is Astronomy Mall.

Good luck, and please e-mail us if you have any questions!

The image at the top of this page was rendered by Brian Thomas

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