First Time Buyers Guide – where do you start?
There’s no one “perfect” telescope — just as there’s no such thing as a perfect car or a perfect house. Instead, you should choose a telescope based on your observing interests, lifestyle, and budget. Many (arguably most) good starter scopes cost $400 or more, though some superb choices are available for under $250.
Here is a guide to help you make sense of the world of telescope models available today. Armed with these few basics, you’ll have a good idea what to look for (and what to avoid) when scouring the marketplace for your new scope.
There are two essentials to look out for: high-quality optics and a steady, smoothly working mount. And all other things being equal, big scopes show more and are easier to use than small ones, but don’t overlook portability and convenience — the best scope for you is the one you’ll actually use.
THERE ARE 3 TYPES OF TELESCOPES:
Generally, telescopes fall into 3 different categories; Refractors, Reflectors and Compound telescopes. These three telescope types use different optics to achieve the same result: making distant objects look bigger and brighter than they appear to your eye.
REFRACTORS have a lens at the front of the tube — it’s the type you’re probably most familiar with. While generally low maintenance, they quickly get expensive as the aperture increases.
REFLECTORS gather light using a mirror at the rear of the main tube. For a given aperture, these are generally the least expensive type, but you’ll need to adjust the optical alignment every now and then.
COMPOUND (or catadioptric) telescopes, which use a combination of lenses and mirrors, offer compact tubes and relatively light weight; two popular designs you’ll often see are called Schmidt-Cassegrains and Maksutov-Cassegrains.
ADVANTAGES
- Lowest cost per inch of aperture
- Simple design, easy to adjust and modify
- Viewing from top of tube allows short tripod (or none in case of Dobsonian)
DISADVANTAGES
- Requires periodic adjustment (collimation)
- Open tube is prone to collect dust
- Usually biggest tube per unit of aperture.
ADVANTAGES
- Best performance per inch of aperture
- Rugged construction, sealed tube
- Usually no need for user adjustment
- Quick cooldown
DISADVANTAGES
- Highest cost per inch of aperture
- Long tube with eyepiece at rear requires tall mount.
ADVANTAGES
- Most compact tube per inch of aperture
- Short tube is easy to mount
- Eyepiece height varies least
- Sealed tube
DISADVANTAGES
- Fairly high cost per inch of aperture
- Requires periodic adjustment (collimation)
- Longest cooldown time of any design.