How to choose a telescope? This is the question dealt most with every day in a telescope store. From the complete beginner to the more experienced astronomer every buyer has a number of questions but the following basics will help with your decision.

Big Question Number One: Land Viewing or Astronomy?

There's a vast difference between the distances involved in terrestrial and astronomy use so its not surprising that for best results it's better to have a telescope designed for one use or the other. We'll come back to the subject of land viewing in another article.

How to Choose a Telescope for Astronomy

First Time Astronomer?

It really is better to do a little research to get aquainted with some of the telescope basics and lingo. Also, leaping into astronomy can be dangerous! Serious injury to your eyes is a certainty if you point it anywhere near the sun. Under some circumstances even the moon can damage your eyes without the right equipment and knowledge of how to use it.

High Expectations?

It's best if you understand that all those great posters on the walls are highly processed pictures from the Hubble Telescope! Seriously, we come across beginners who think they can reproduce those images by spending a few bucks for eyepieces and accessories "for the scope they got off eBay"! Be very wary of ads promoting telescopes with words like "500 Power" and non specialist stores offering great deals on "High Power" telescopes.

Buying a Telescope? Confused? - Learn a little and Make it all easier with TelescopeChoice.com - Discount Telescopes

or visit the lens: Telescopes for Beginners - Choosing a Good Beginners Telescope

Portability and Useability

How to choose a telescope depends on several factors. No use having a huge fancy telescope if its so hard to set up that you rarely feel inclined! Having lugged hundreds of scopes I can tell you they are not the easiest things to handle and can be so large and heavy as to risk damage to your back. Telescopes and mounts weigh up to 20kgs each. Remember the easier the telescope is to use the more likely you will be to use it and the greater enjoyment you'll get from it so do take ease of use into consideration.

Location

You must also consider where the majority of your viewing will be taking place as light pollution tends to make use of large aperture scopes difficult in the suburbs whereas in a dark sky location you will definitely want to reach further than a small refractor will allow.

Budget

Aha! - It is possible to spend from under a hundred dollars to many thousands. A small beginner refractor might only cost about a hundred of your hard-earned but should allow decent lunar views and a bit of casual stargazing. If you're after sheer 'power' then go for the largest aperture you can afford but be aware that large apertures are not so good in light polluted areas like the suburbs of most cities. If you're after 'bang for buck' then the Dobsonian type telescopes offer large apertures at just a few hundred dollars.

Refractors have a primary lens at the front end bringing light to a focus point and the eyepiece at the rear of the scope. This type is commonly used for land viewing but are also used for astronomy, indeed it was the first astronomical scope. They tend to produce clear sharp images and are at an advantage in the suburbs where light pollution is a huge factor to contend with. Large aperture refractors can be difficult to use and very expensive so tend to be relatively rarely used in practice.

Reflectors on the on the hand, use a mirror for light gathering and reflect the light to the eyepiece via another small mirror called the secondary mirror. Reflectors tend to offer a combination of medium to large apertures with ease of use and are most often used for astronomy. Larger reflectors are sometimes mounted on simple lazy-susan turntables known as Dobsonian mounts. They are extremely easy to use and their large apertures offer excellent deep-sky viewing.

Catadioptric Telescopes such as Schmidt-Cassegrains & Maksetov-Cassegrains, package relatively large apertures with short tubes for ease of handling and portability. They achieve this by reflecting the gathered light twice inside the tube before passing it out to the eyepiece. They are usually mounted on computerised mounts, making navigation easy (after you learn how to align and contol them properly). Their more complicated construction tends to make them fairly expensive but their all round capabilities make them very popular.

Telescope Mounts

Of course the telescope is useless without a means of supporting it to allow the observer to use it. Simple mounts like the alt-azimuth mount are usually used for land viewing and more casual astronomy. They allow up-down and side to side movement of the telescope tube. The Dobsonian mount mentioned earlier for large aperture reflectors is actually a type of alt-az mount.

Equatorial mounts are more complex and allow the telescope tube to move through an arc which is essential for tracking an object as it moves through our sky. They can be motor driven and controlled through a hand controller. The many variations of these tend to be popular with serious astronomers and astrophotographers.

However good the telescope, it will be limited by the quality of the mount. Cheap scopes tend to come on cheap mounts that allow the telescope to move with the wind or even vibrations from passing traffic.

Zhumell 10-inch Dobsonian

A larger dobsonian from Zhumell, an excellent big scope simple enough for beginners yet powerful enough to see just about anything with a bit of practice!