The observable universe is certainly filled with plenty of amazing things. However, because of our relative distance to pretty much anything that isn’t on Earth; we need assistance to observe them. Besides the visible spectrum of light, there is just as much light that we cannot perceive with the naked eye.
That’s why instruments like telescopes are important. There are different kinds of these devices; some of them are visible light telescopes that can help us see visible but distant objects. Often enough, the same instruments can also help us detect and measure hidden light.
But picking one for yourself is a little easier said than done. With prices from tens to thousands of dollars, and all sorts of interesting technologies and features, how do you actually choose a telescope?
Of course, some of these are not easy to understand, let alone to decide on!
Here’s how to choose a telescope, with first-time buyers in mind!
1. Understand the basics of telescope optics
It’s important to note that most objects found in space radiate some kind of light. Depending on the light’s energy and wavelength, we give it different denominations. There are gamma rays (popularized by the Hulk), X-rays, ultraviolet, visible light, infrared, and so on.
This entire range is called the electromagnetic spectrum by scientists. The word “light” isn’t used in this context because of the wrong general perception; a majority of people would only define light as something that they can see.
Telescopes help us see parts of the visible light spectrum — but other things as well. And make no mistake, there’s nothing quite like gazing at the night sky through the lens of a telescope. Even on an ordinary evening, the things that you can see are breathtaking. And once you get into it, there are all kinds of interesting astronomical events that you can witness and observe; lunar eclipses are just some of the more famous ones.
However, before you can do any of that, you have to obtain a telescope in the first place. And even armed with the knowledge of what a visible light telescope is — you’ve still only scratched the surface of what you need to know.
Picking the first telescope that you’re going to purchase is not easy. There are plenty of different designs and manufacturers out there — and you probably don’t know the first thing about visible light telescopes. Don’t worry, though; we’ll break down the basics for you.
2. Decide where you’ll observe from
Contrary to what some people might think, positioning your telescope is one of the first things that you need to think about; even before you’ve bought one. That’s because what you’ll see through a telescope also depends on where you’re situated on Earth.
For instance — if you live in a bigger town or a bustling city, you’ll be surrounded by all kinds of buildings and street lights. This is something you don’t generally think about often; but when operating a telescope, this can present a difficulty.
All of these Earthly lights cause an effect dubbed a “light dome”. And this dome will affect the clarity of your telescope’s vision because it creates something like a haze; if you’ve heard of the term ‘light pollution’ then that’s what we’re talking about.
Said haze can easily block out the more distant and fainter nebulas, galaxies, and individual stars. So, if you’re in an urban area, prepare to have your astronomical field of view somewhat narrowed. People who live in cities mostly observe the brightest objects found in the deep sky, as well as nearby planetary and Lunar objects.
On the other hand, someone living in the countryside won’t have the same limitations imposed by light pollution. There, you can get visible light telescopes with bigger aperture scopes; those that will enable you to observe entire distant star clusters.
3. Prioritize what you’d like to observe
Again, the perception that astronomy is some sort of homogeneous whole is simply wrong. In reality, this is an incredibly broad hobby; one that allows you to specialize in plenty of specific fields of interest. If you’re an amateur, you can perform all kinds of star studies and observe the solar system.
Of course, you don’t need to get into that much detail to appreciate the beauty of astronomy. You could always just enjoy the aesthetic of viewing the heavens, or simply gaze at the moon on a clear evening.
4. Settle on a budget
The prices of telescopes are as varied as the devices themselves. You could get a tiny refractor visible light telescope for a hundred bucks or could pay tens of thousands of dollars for huge catadioptric devices. It all depends on how serious you are about astronomy, and how much money you’re willing to invest. Though, generally — we advise starting small and seeing how things develop from there.
There are some terrific telescope bargains these days, since modern manufacturing has become incredibly efficient. In most cases, something like $100-$200 is the cheapest price range worth buying. Read this article for more guidance on the pros and cons of budget telescopes.
5. Consider your portability requirements
While choosing your first telescope, you should also think about its weight and size. In fact, this is one of the biggest practical issues that many beginner astronomers fail to consider. Some telescopes weigh no more than 20 pounds — and some are more than ten times heavier.
When you transport a telescope, you usually break it down and assemble it later. There’s the base or the tripod, the mount, and the assembly for the optical tube. But even when it’s not assembled, it can prove to be tough to move. So, if you can’t handle the weight of the telescope; everything else doesn’t matter!
6. Settle on one style of telescope
In the world of astronomy, there are three major types of visible light telescopes:
This is a great old-fashioned telescope design. One of its main advantages is that there’s not much maintenance that you’ll have to perform as a beginner. These telescopes are made out of multiple lenses that bend beams of light before it becomes focused at the tube’s end.
Refractors can be excellent if you want to image and view brighter objects, lunar objects, nearby comets, planets, and bright double stars.
- Clear star imagery
- Lack of central obstruction
- Color correction
- No cleaning of dirt and dust
- Color dispersion issues on low-end models
- Rising costs for bigger lens instruments because of exotic glass types
The second type of telescope is the reflector — its design is elegant and simple. Most of them consist of two mirrors that serve to direct light into the observer’s eyepiece. These telescopes are quite cost-effective in upper aperture sizes; particularly in comparison with the previously described design. You can use the for Astro-imaging, and planetary observations.
- Not expensive
- Great color correction
- No color dispersion issues
- Dirt and dust accumulation
- Central obstruction
- Bigger tube size
These are telescopes with completely closed tubes; that means you won’t have to deal with accumulations of dirt and dust. Also, air currents aren’t an issue as a consequence, and these are pretty portable devices.
Catadioptric telescopes are also known as “compound” devices because they are a combination of lens and mirrors from the previous two designs. This type of telescope can be used for any kind of astronomical observation, unlike the previous two.
- No debris accumulation
- Portable design
- Need more time to cool down
7. Finally, figure out power and mount needs
The power, or magnification of a telescope, represents an important variable; usually dependent on the type of eyepiece that the observer uses. When we say a variable, we mean that in a literal sense — you get it by dividing the aperture’s focal length by the eyepiece’s focal length.
As for the mounts that telescopes use, there are a couple of different kinds. A telescope usually comes with a mount, but you can purchase others as well.
The first one is the Altazimuth mount. It’s the simplest one of them all. You can move it left or right along the azimuth vector, or vertically according to altitude. Compared to the equatorial mounts that we’ll describe below, they’re far easier to use — and also lighter.
Speaking of which — equatorial mounts move according to a different axis — east-west and north-south. You use the polar axis to align the telescope properly — allowing you to track objects from there. These days, equatorial telescope mounts are usually equipped with computer systems that make navigation far easier.
Before you set out to buy your first telescope, we urge you to think long and hard about all of the factors that we’ve described above. Also, bear in mind that it’s not enough to read one article in order to understand the complex nature of telescopes and astronomy.
So, before investing in such a device — our recommendation would be to join an astronomy club if there’s a local one in your area. Its members will likely be more than happy to help you out with any questions you might have. And of course, all that’s left then is to enjoy your gorgeous view of the night sky! We hope that this guide was useful to you and that you feel more confident about your knowledge of visible light telescopes. Stay safe and have a good one, folks!