Buying a Telescope

There are a wide range of telescopes with an ever increasing range of features and capabilities; they can also be hugely expensive, so it’s important to choose the right one. Which features do you need? Keping this in mind will ensure you buy a telescope which will meet your needs perfectly. Here are the main features to consider.

The key feature is aperture and you should get as much as you can afford. Refractor telescopes need at least 3 inches or 80 mm. Reflector telescopes, 4-8 inches or 10 – 20 mm and Compound telescopes 6-8 inches or 16 – 20 mm. However keep in mind other features, as the biggest telescope many not be the best.

High power magnification isn’t always necessary. The scopes' ability to enlarge an object is due to the lenses and focal length. Most objects can be seen at lowest magnification because the most light is being focused. I suggest 40 -60x magnification per 1 inch of aperture is sufficient for most cases.

Another feature to look out for includes a focuser – which moves the eyepiece up and down to help adjust the focus. These come in two types: Friction focusers and Rack and Pinion focusers. There should also be two eyepieces to allow you to vary the magnification of the object, some telescopes come with none. Eyepieces should fit the telescopes eyepiece holder as sizes vary.

Finally, mounts are important for stability and thus should be easily adjustable whilst maintaining a low centre of gravity and stand securely on even and rough surfaces. Adjustable mounts allow you to alter the height of your telescope so you are comfortable.

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