Which criteria should I consider before I buy a telescope ?

Question

I need a telescope which is able to reach stars.....

Answer 1

The most important single property of a telescope is its aperture (the diameter of the main lens or mirror). This will determine how faint and how small a detail you can see with it. Buy the largest aperture telescope that you can afford and that is still easy for you to set up and transport. A four to eight inch dobsonian is what I generally recommend to beginners.

Learn something of how telescopes are used, and what they can do, so you'll have realistic expectations. If possible, visit a star party and see for yourself. Consider how you're going to find things in the sky. Most amateurs learn to star hop, first using guide books like "Turn Left at Orion", and graduate to a star atlas. You can also get computerized scopes that will find objects fo you, but at the low end you wind up giving up a lot of capability to get the electronics.

There are three basic types of telescopes available for sale.
1) Refractor. A telescope with a lens. These are rugged and foolproof, but beginner refractors are small aperture, and bigger refractors and expensive, and cumbersome to mount. Usually the most expensive telescope for a given aperture, but available in very small and therefore inexpensive sizes.
2). Newtonian reflector. The simplest optical design, using one figured mirror and one flat to divert the light to the eyepiece. Needs occasional adjustment. The dobsonian is a Newtonian on a very simple mount and gives you the most telescope for your money.
3) Cassegrain or catadioptric. Compound reflector telescopes (e.g. Schmidt-Cassegrain or Maksutov-Cassegrain) with short stubby tubes, most often with a corrector plate on the front. Very good for astrophotography and technical uses. require occasional adjustment.

Buy from a reputable astronomical telescope store, not Walmart, the camera store, or eBay.

Answer 2

Some of the folks above are offering good advice. To add, I would suggest starting small and simple for your first telescope to get some first hand experience. You may discover that you like the idea of owning a telescope more than actually using one, for example, and save yourself a lot of money. Perhaps an 6" Newtonian with an equatorial mount and clock drive from Meade. This description is an example of the 4 most important criteria in order of importance (IMO): aperture, optical configuration, mount type, and manufacturer. You should research the tradeoffs of all the options in each criterion before buying anything that challenges your budget.

Answer 3

A good pair of binoculars with a nice tripod is encouraged for the beginner. This is because of simplicity of use and it has utility beyond just star gazing if you decide you are not all that into star gazing after all. With binoculars you can see the 4 largest moons of Jupiter as they go around it, and see Jupiter as a disk. You have a decent shot at making out Saturns rings, or at least that Saturn is not quite round.

You can see all kinds of cool stuff on the moon, (craters, mountains, rays, maybe some rilles) and open star clusters are BEST viewed through binoculars' wide field of view rather than a telescope. More of the brighter stars have distinct colors too, rather than those just hinted at with the naked eye. Globular clusters and the brighter nebula are tantalyzingly enhanced.

This site has a good intro to telescopes if you insist on plunging into that route immediately, though I encourage you to hook up with a local astronomy club to find help using your new toy or you might find yourself frustrated and putting it in your basement to collect dust for the rest of its life.

http://www.belmontnc.org/

This is a pretty good essay about getting your first scope too.
http://www.scopereviews.com/begin.html

Answer 4

Budget and light pollution.

Consider going to a local "star party" and getting to know some local amateur astronomers. That way you will get to try many different telescopes and talk with the owners about their likes and dislikes.
If you have an observatory nearby, they often host events that would give you similar opportunities.
Finally, www.telescopes.com had some great prices when I purchased last Christmas, and they were good to deal with.

Answer 5

In addition to some of the other excellent answers, I would like to add that you should consider the type of mount you will be using as well. Should you need a motorized mount or a non motorized one, should it be an equatorial mount or an alt/az mount. Many of these questions will be answered by knowing what you plan to do with your telescope.

Answer 6

This website is a great place to start.

Answer 7

price and what you want to see,maybe space

Answer 8

price,zoom & lense quality

and

they can't because they're not long enough