TMCnet Feature
September 26, 2019

How to Make Sure You Picked the Right Telescope



If there would be just one single telescope to meet all requirements and make everyone happy, we’re sure you wouldn’t be reading this guide. However, the beauty of it is that you can choose various items, depending on your needs and how far you wish to see. Most stargazers, pros, and amateurs alike, will end up owning more than one telescope. 



Some are smaller and more compact, while other devices allow you to see a clearer picture of what’s going on in the universe. Some tools even allow you to take photos of the starred skies, while others are more appropriate for surveilling your neighborhood. Therefore, before knowing how to pick the right telescope, you need to know what you are aiming for. 

Magnification rate

We should start by saying that no reputable telescope seller will have the magnification rate advertised on the box. This is only available for poorly made items and beginners. Worst case scenario, you can pick one of these gizmos for your child as a first tool to gaze at the universe, although we doubt they will be able to see much. 

Ultimately, these amateur telescopes won’t even function properly, building up frustration instead of interest for astronomy. Thus, we don’t recommend buying such an item from warehouses, department stores or malls. You should always head to specialized stores or order them online, once you are sure which item is right for you. 

Quality vs. design 

Telescopes come in countless shapes, sizes, and designs, so you must know what to look for. A brass telescope with tripod may look cool but will be mainly serving a decorative purpose.

Although some products allow you to see the stars, the image will rarely be clear. These pieces are also more affordable than “the real deal” but are mainly designed to look pretty instead of helping you see a certain star or galaxy on a clear sky. 

In the world of telescopes, quality is often translated by a higher price. A good telescope can cost up to several thousands of dollars, depending on its size and functions. 

Refractor, reflector or catadioptric?

As we previously mentioned, passionate astronomers will have a few telescopes, each serving a different purpose. 

A refractor telescope is probably the most desired item by stargazers, as well as the most expensive. Most of these devices provide excellent image quality with no obstruction in the light path. On the other hand, they are also heavy pieces of equipment and take time to mount and adjust. 

The reflector telescope was invented by Isaac Newton to fix the issues with the chromatic aberration of refractor pieces. These devices use a parabolic mirror to focus light as opposed to the others that use lenses. 

Although they are more affordable per inch of aperture, they will often require collimation of optics. Some also argue that the quality of the image you see is inferior to that provided by refractor telescopes.

Catadioptric items use both lenses and mirrors to deliver the image of the sky. They are quite common, affordable and, most importantly, they have a compact design. 

This means that you can get to use them anywhere you want and even transport them to remote locations such as camping sites or hills whenever you want to look at the stars. The main disadvantage of a catadioptric telescope is that the images resulted are not always clear. 

You can invest in such a product if you are new in the field of astronomy or simply want to see stars closer than with a clear eye. 

Aperture

The most important characteristic of a telescope is the diameter of its light-gathering mirror or lens, mainly known as the objective or the aperture. Usually, the aperture’s diameter (D) is expressed in millimeters and should be as wide as possible. Ideally, you should opt for telescopes with an aperture diameter of at least 70 mm. 

A larger aperture helps you see fainter objects and more details on the sky but it also depends on how dark it is outside or how clear the sky is. For instance, you can spot numerous galaxies apart from our own from a dark location with the help of an 80mm-aperture scope. 

However, you’ll need an aperture diameter of 160mm or even 200mm to be able to see the same stars and galaxies from suburban locations. 

Multiple eyepieces

There isn’t an exact number of eyepieces you should own for your telescope but some would say the more, the merrier. It depends on the type of object you plan on seeing, as well as the sky and lighting conditions. 

As a general rule, you’ll want to start with a long focal length eyepiece of about 30mm to adjust the telescope’s field of view according to the object you are seeing. Once you got that covered, you can choose a shorter focal length of around 15mm. 



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