Buying the Best Beginner Telescopes For Amateur Astronomers

If you are new to the world of telescopes you are probably wondering which is the best beginner telescope and how you should make your decision. Whether you are looking to take advantage of an after the holiday sale, or maybe cash in a gift card on a new telescope you may need help making your decision.

There is an assortment of telescope technology available for you to choose from: Refractors, Reflectors, Dobsonians, Cassegrains and Catadioptrics, and don’t forget the computerized models to complicate your decision. Cost is an issue to be considered as are ease of use, maintenance, storage and portability. Are you interested in astrophotography or just want to take a look at whatever is up in the sky tonight? These and other factors will come to bear as you make your final decision in buying a telescope—but first, let’s find out what the different technology is all about.

Refractors: The classical telescope that probably comes to mind when one thinks of a telescope. When you think about the history of telescopes you may invision images of Galileo   peering through his telescope, or the ever-present pirate on the high seas looking through his “spy glass” for unsuspecting victims. These telescopes were nothing more than a tube with lenses in it to focus and magnify the image that was being viewed. These are refracting telescopes. The light that is coming from the object you are viewing passes trough a lens at the end of the telescope, the objective lens, which bends, or refracts the light to a point and then through a lens in the eyepiece to magnify the image. 

Today’s modern refracting telescopes don’t suffer from the problems that plagued the early astronomers, with poorly ground lenses and inferior glass providing anything but a sharp, clear image. Refracting telescopes manufactured today tend to be very rugged and maintenance free due to the fact that the optical tube is closed with lenses on either end, there is no chance of dust accumulating on the optics. Because the lenses are fixed, one does not have periodic adjustments to make to fine-tune the optics as is required with a reflecting telescope. This convenience comes at a price and refractors tend to be expensive and the price increases dramatically as your objective lens size increases, as does the length of the optical tube. Refracting telescopes, and other small telescopes, provide very high contrast, small field of view and are the telescope of choice for planetary viewing and photography. Refractors work well with electric drive systems and the computerized locate and track systems available today.

The next most common telescope that might come to mind is the Newtonian reflector. This telescope uses mirrors and lenses to bring the image to the observer. The figures below illustrate the construction of a typical reflecting telescope along with an image of the Cassegrain telescope, which places the eyepiece at the back of the telescope, more like the conventional refractor design.

The light from the observed object enters the open end of the optical tube and bounces off a curved mirror at the base of the tube, the primary mirror. The reflected rays then reflect off the secondary mirror and are focused through a lens in the eyepiece. This type of construction allows for a very inexpensive, high quality telescope with a lot of light gathering capability providing very bright, high contrast images. The down side of this construction is that the mirrors may be knocked out of alignment as the telescope is ported from one location to another and may need adjustment. Also, the open tube allows dust to collect on the surface of the mirrors deteriorating the image over time and require careful cleaning.