A Beginner's Guide To Choosing A Telescope

Before buying a telescope, know which features count and which don’t

Team RD Published Nov 4, 2020 20:52:06 IST
A Beginner's Guide To Choosing A Telescope Photo: Shutterstock

Do you love stargazing? If the answer is yes, then you should definitely consider investing in a telescope, if you haven’t already. If you are an amateur astronomer and are planning to buy your first telescope, here are a few things you must keep in mind:

1. Regardless of the type of telescope you opt for, the aperture is the most important aspect of a telescope. In plain terms, aperture is the diametre of the mirror or the lens of your telescope. The bigger the aperture, the better the picture. That’s because the aperture determines the brightness and sharpness of the image. However, know that bigger aperture means bigger telescope. If you want to travel with your telescope, you may want to keep an eye on the size.

2. When it comes to an optical instrument, one of the most frequent queries is regarding its magnifying power. In the case of a telescope, you can enhance it as much as you want by changing the eyepiece. Don’t go beyond a limit where the image becomes blurry. Also, don’t lose sleep over magnification because the quality of an image is determined by the size of the aperture and the atmospheric conditions.

3. Telescopes comes in all shapes and sizes, but can still be classified into three broad categories: reflectors, refractors and Cassegrains. A refracting telescope uses a lens to focus the light and you see the magnified image through the eyepiece located at its end. It is low on maintenance and easy to set-up. But refractors with large lenses (read bigger aperture) are not easy on the pocket.

4. For amateurs who don’t want to spend too much on a telescope, a reflector telescope may be better bet. Reflectors use mirror to focus the light and the eyepiece is located on the side of the tube. The design of a reflector is such that it allows for bigger apertures compared to refractors. However, it requires periodic maintenance.

5. The third type of telescope, Cassegrains, combines the best features of refractors and reflectors. A Cassegrain telescope uses both mirror and lens to form an image. It has a big aperture but its design is compact, which makes it easy to store. For the same-size aperture, a Cassegrain telescope will cost a bit more than a reflector but less than a refractor.     

Once you know your budget, it is easy to choose a telescope that you like.


Do You Like This Story?
Other Stories