Among the myriad types of telescopes available, Dobsonian telescopes, or "Dobs", far and above, offer the best performance for the dollar for both amateur and seasoned astronomers alike to really see the sky.
Why are Orion and so many amateur astronomers so enthusiastic about Dobsonian telescopes?
- Light Gathering Power: In astronomy, it's all about light, the more light you collect (i.e. the bigger the mirror your telescope has) the better you will see things. Dobsonians generally feature large mirrors in simple telescope bodies to give you a LOT of light or the most 'image' for your observing dollar. Dobsonians are classified by their diameter; an 8-inch Dob, such as the Orion XT8 has a mirror 8-inchs in diameter — and that gathers over 800 times the light that your eye can!
- As Said Before, Simplicity: Dobsonians were "invented" to have as few moving parts as possible. The "average Joe" can transport, quickly set up, and easily use it with minimal fuss. Because the majority of the cost is the optics and everything else is kept very simple, a Dobsonian telescope is very inexpensive for its size. Orion has many low-cost models.
- Portability: Dobsonians, until you get a Dob that's larger than about 8 or 10 inches in diameter, are remarkably portable for the size of the mirror (the light gathering power) they offer. Size and portability are relative and in the-eye-of-the-beholder; Orion suggests you carefully consider the size of any Dob before you buy (by comparison charts, such as the one below, or look at the photos with something for scale or people next to them) — an 8-inch telescope is not a tiny department store telescope.
- Easy to Operate: The Dobsonian telescope tube literally rests atop a lazy-susan-type of altazimuth base that allows simple, yet very smooth Left-Right and Up-down motion. This simple arrangement also allows for flexibility and easy set-up. Another added bonus is that these types of telescopes can usually be managed by aspiring astronomers of all ages.
- Accessible: The Dobsonian's affordable, low-cost, and portable design makes these types of telescopes available to nearly anyone and everyone. If you are looking for a quality "starter" telescope, the Dobsonian is your best bet. If you are looking for a good step-up replacement telescope to the one you've had for the past 25 years, on the other hand, well, you may have found YOUR pick as well.
Of course, nothing in this world is perfect. Fully reaping the benefits of a Dobsonian, or any other type of telescope, requires that you find the least light-polluted areas accessible so that the large diameter objective lens can work its magic of pulling light from distant stars and planets through the eyepiece for your viewing pleasure. Also, unless you opt for a motorized Dobsonian equipped with computerized GoTo technology such as the Orion XTg and XXg series, you will have to manually nudge the telescope every few minutes in order to keep your object centered in the eyepiece, since the altazimuth bases of non-motorized Dobsonian reflectors do not enjoy the same tracking ability as clock-driven equatorial mounted telescopes. Lastly, keep in mind that while Dobsonians excel at deep space viewing, they still give marvelous views of the moon and planets, which appear much more impressive than what we see with the naked eye.
Overall, a Dobsonian telescope will give you, the amateur, novice, and seasoned astronomers out there, the thrill of (albeit temporarily) leaving this world behind to visually soar among the heavens.