How to Buy a Telescope

Man and child viewing with a telescope at dusk

Here are a few tips Dr. Billy Teets shares with anyone interested in getting a telescope:

We often refer folks to Dobsonian telescopes as they give you the most light-gathering bang for your buck.  These telescopes are more suited for visual observing rather than photography, but one can still get really nice images of the Moon and some of the planets, sometimes even with just a smartphone.  The cost is relatively inexpensive when considering the image quality, overall mirror size, and that they do not require a special setup or alignment to begin observing – you just set a typical Dobsonian on the ground and manually move it around to where you want to look.

A Dobsonian Telescope
An example of a Dobsonian telescope.

Brands will sometimes have a model number that indicates the size of the telescope primary mirror in inches or millimeters.  Typical sizes are 4.5”, 6”, 8”, 10”, and 12.”  The bigger the mirror, the fainter the object that can be viewed, and the better the resolution; however, the price climbs and the telescope becomes heavier. All of these sizes will enable you to see the rings of Saturn and the four large moons of Jupiter. You may put forth a bit more money at the beginning; however, these telescopes will last a lifetime if taken care of. We have several at Dyer, and I have had a 10” version at home for about 20 years.  There are even tabletop versions that are much more compact and easier to move from location to location; however, the user may need to have a small table handy to set the telescope on for more convenient viewing.

We often recommend a Dobsonian telescope over a traditional refractor because you get more light-gathering power and there is less color distortion (chromatic aberration). Refractors use lenses instead of mirrors, and as light passes through those lenses it will begin to separate into its component colors. Objects like the Moon will have a colored ring around them, which can make the view unfavorable.  Having said this, if you are not sure of the interest level, a refractor may be a way to start and minimize the cost.  There are high-end refractors that don’t suffer from this color distortion nearly as much, but they can often run thousands of dollars for even a small one.

A refracting telescope
A traditional refracting telescope.

No matter which one you choose, if you take decent care of the telescope (keep the dust cover on when not in use, don’t bang it around much, etc.), it can literally last you a lifetime. By the way, if you are local to the area, the Barnard-Seyfert Astronomical Society usually hosts monthly star parties, and they encourage folks to attend for free. You’d have the opportunity to look through telescopes of various types and sizes and chat with seasoned amateur astronomers about their recommendations.

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