ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

A Basic Guide to Telescopes, Explaining How They Gather and Concentrate Light Rays

Updated on June 8, 2019
stephaniedas profile image

Stephanie is a student who enjoys accumulating books and recipes. She wants to be a Wizard when she grows up.

A telescope may be one of your favorite investments.

Everyone who owns a nice telescope knows how much fun they can be. If you're planning on buying one but want to make an educated purchase, check out the information I've put together below.

Looking through a telescope at the night sky.
Looking through a telescope at the night sky.

How to Calculate the Magnifying Power of a Telescope

You will see numbers printed on the telescope that tell you the width of the lens and the eyepiece. If the objective lens is 2000 mm and the eyepiece is 40 mm, divide 2000 by 40.

2000 / 40 = 25.

This means that your telescope magnifies the image 25 times.

Telescope aren't just for looking!

The other types of telescopes include radio telescopes that read radio waves, UV telescopes that see ultraviolet light, which humans cannot see, gamma ray, x-ray, infra red telescopes, and many more!

Below is a picture of a SKA (square kilometer array) site in Australia. These are powerful radio telescopes that are meant to pick up radio noise coming from space. These were featured in the movie Contact, which stared Jodi Foster.

Radio telescopes, SKA Australia
Radio telescopes, SKA Australia

Reflecting Telescopes

Almost all of the major telescopes used in astronomy are reflecting telescopes. There are many different designs, but I've included the most basic here so you can easily get an idea of how they work.

In this image, your eye would be at the focus of the telescope. The light is shown entering from the right, and hitting the primary mirror on the left. Notice that the primary mirror is curved, which causes the light rays to come together. The light hits the secondary mirror, which concentrates the light even more, sending it to you eye.

Reflecting telescope
Reflecting telescope

Refracting Telescopes

These aren't too common anymore. Check out the image below.

It shows the light entering the objective lens from the right. The objective lens bends the light so it comes together before entering the eyepiece lens. So, the refracting telescope and the reflecting telescope accomplish the same thing in two different ways.

refracting telescope
refracting telescope

Telescope Bits and Pieces

  • Some telescopes show the image backwards and upside down. This doesn't really matter, because whose to say whats up, down, front, and back when you're in the middle of space? However, if it bothers you, you can buy an eyepiece to correct this.
  • When purchasing your telescope, remember that you don't need the telescope with the biggest lens or longest body.
  • What you need is a good magnification and a sturdy tripod, without which you won't be able to see anything.
  • If you're not ready to invest at least $100 in a good telescope, don't buy one a cheap one from Wal-Mart, because it isn't worth your money.
  • You would be better off investing $50 in a nice pair of binoculars, which will also allow you to see many details of the moon's surface, the phases of Venus, Jupiter's moons, Saturn's rings, and much more.

Have fun!

Celestron - AstroMaster 70AZ Telescope - Refractor Telescope - Fully Coated Glass Optics - Adjustable Height Tripod – Bonus Astronomy Software Package
Celestron - AstroMaster 70AZ Telescope - Refractor Telescope - Fully Coated Glass Optics - Adjustable Height Tripod – Bonus Astronomy Software Package
This is the brand that my parents bought for me when I was 8. I'm now in my early 20s, and I still use it.

This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

Show Details
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
ClickscoThis is a data management platform studying reader behavior (Privacy Policy)