Refracting Telescope Explained

Refracting Telescope Explained

A refracting telescope is a type of optical instrument that allows you to view faraway objects close up. If you are into astronomy, you may have heard of this instrument. 

Perhaps you are trying to decide what kind of telescope to use since there are three main kinds of telescopes on the market. 

This guide will explain everything you need to know about refracting telescopes. We will cover what a refracting telescope is and how it works. 

We will also explain the different parts of a refracting telescope and how to use one.

By the end of this guide, you will know everything you need to know about this model and will know if it is the right instrument for you. 

Keep on reading to learn more. 

What Is a Refracting Telescope?

What Is a Refracting Telescope?

A refracting telescope is a type of optical instrument that allows you to see faraway objects close up.

Most people use refracting telescopes for astronomy and observe planets or other terrestrial objects in the night sky. The instrument uses an objective lens to collect light to form an image. 

Historians have traced the first refracting telescope to the 17th century in the Netherlands. A man named Hans Lippershey attempted to create one but was unsuccessful.

However, when Galileo Galilei heard of the failed invention, he attempted to create one himself.

A year later, Galileo invented a refracting telescope of his own and used the instrument for astronomy.

Most refracting telescopes will consist of a long body tube, a finderscope, a mount or tripod, a lens near the front and an eyepiece near the back of the instrument.

Users will look through the eyepiece to see the final image that the telescope produces. 

Astronomers use refracting telescopes to observe visible light wavelengths of the electromagnetic spectrum.

Some terrestrial objects that you can see with refracting telescopes include the moon, double stars and planets such as Mars and Jupiter. 

Refracting telescopes are one of the most common telescopes that you will find on the market. They are quite low maintenance but are on the higher end of the price range.

The average price range of a refracting telescope is around $500 to $1500, depending on the make and model. 

These instruments also come in a few different sizes. Whether you want a telescope for your backyard or even your bedroom, it will be easy to find a model.  

Many beginners prefer to use a refractor telescope since there is not as steep of a learning curve compared to other types of telescopes.

It is pretty simple to use and will not require a lot of adjusting once you set it up. 

How Does It Work

How Does It Work

If you are a beginner, it may be daunting trying to learn how a refractor telescope works.

Even though telescopes are complex machines, it doesn’t mean it is impossible to understand how they work.

Let’s take a look at the technology behind these optical instruments. 

Refraction of Light

Before we get into how a refracting telescope works, let’s examine the concept behind the technology: refraction of light. 

Refraction refers to the phenomenon when light bends as it passes through one substance to another.

Light refracts whenever it passes through a translucent substance at an angle.

For light to refract, the substance needs to have a different optical density. Optical density refers to how easily something transfers through the substance. 

How the Telescope Works

Now that we know what refraction means let’s examine how this concept applies to the telescope. 

A refracting telescope has two main lenses called the eyepiece lens and the objective lens.

These are two of the most important telescope components, which we will discuss in more detail later. 

As the light enters the telescope, these lenses refract, focus, and magnifies the light. They also increase the clarity and brightness of the magnified image.

Some telescopes will also have a second smaller lens behind the eyepiece of the telescope.

This lens will make sure that the image is the right orientation and is not upside down. 

The objective lens and eyepiece lens are both curved lenses, which are called convex lenses. When light passes through a convex lens, it bends the light inwards.

As the light bends inward, it collects and gathers to a single point called the focal point. The distance from the focal point to the lens is called the focal length.

The focal length determines how much the telescope magnifies the image.

Parts of the Refracting Telescope

Parts of the Refracting Telescope

Even though refracting telescopes look like complex machines, there are only a few basic parts that play essential roles.

Let’s take a look at the different parts of a refracting telescope.

The Objective Lens

The main job of the objective lens is to gather and collect light. Objective lenses are typically the largest lens on the telescope. 

Objective lenses are responsible for refracting the light that enters the telescope and converging it into one main focal point. 

As a general rule of thumb, the bigger your object lens is, the more light can enter. A large objective lens is always better than a small one.

If your telescope has a large objective lens, it will also improve the quality of the final image and will help you observe terrestrial objects that are deeper in space. 

On the other hand, you will experience limitations with a small objective lens. The image may be a bit blurry, and you won’t be able to see as many objects in space.

The Eyepiece Lens

The eyepiece lens, also called the magnification lens, determines the magnification power of the telescope.

The eyepiece lens is normally the lens that is closest to the user’s eye. You look through this lens to see the magnified image of the object you are looking at.

Furthermore, on most telescopes, you can adjust the eyepiece lens to focus the image. 

On newer models, you can replace these lenses with various eyepiece lenses, depending on your preference.

Telescope users will normally replace the lenses if they want stronger (or lower) magnification powers. 

The eyepieces that originally come with the telescope are usually not the highest quality, which is why many people will buy extra eyepieces. 

Telescope Tube

Next is the telescope tube. This part is the main body of the telescope and holds essential components such as the lenses.

While different tubes will be different sizes, one of the most common sizes you will see is 8-inch tubes. 

Besides holding the telescope’s essential lenses, the tube also helps by improving the focal length.

The focal length helps to magnify the image, and you can usually adjust the focal length by using the finderscope. 


The finderscope is a crucial part of the telescope. It is essentially a miniature telescope attached to the body of the main telescope.

Telescope users will use the finderscope to initially locate the object that they want to observe. 

This component makes it easy to find terrestrial objects since it has a wider field of view than the telescope has and a lower magnification level.

Once you find the object with the finderscope, you can then look through the telescope and study it. 

The Mount and Tripod

Telescope mounts and tripods keep the optical instrument stable as you are using it. Since most telescopes are very heavy instruments that cannot be handheld, it is the job of the tripod to support it. 

Not only do the mounts and tripods keep the instrument safe, but they also allow you to move the telescope either up and down or left to right as you scan the night sky.

Without these parts, you would not be able to find objects in the sky. 

How To Use a Refracting Telescope

How To Use a Refracting Telescope

Now that we know how a refracting telescope works, it is time to find out how to use one.

These instruments are complex machines that have a bit of a learning curve. With these tips, you will get it in no time.

  • Become familiar with your mount and tripod. The first thing you need to do is to practice using your mount and tripod. Each tripod will be different and will have a bit of a learning curve. It is best to know exactly how to move your telescope before you go out to observe. The last thing you want to do is spend half an hour figuring out your tripod in the cold. 
  • Choose a location. The next thing you should do is pick a location. Make sure you choose a place that is far from city lights. Ideally, you want to go to the darkest place possible. If there are lights around, it will be more difficult to see faint objects in the sky. 
  • Set your tripod up. Now that you have your location, you can set the tripod up. Make sure that the legs are all the same length and that you tighten each leg. Mount your telescope into the tripod and tighten the screws.
  • Set up the finderscope. Insert the finderscope on the telescope mount and tighten the screws and knobs. 
  • Aim the telescope at an object. Before looking through the telescope or finderscope, choose an object you want to observe and aim the telescope in that general direction. 
  • Use the finderscope to adjust your aim. After choosing an object, use the finderscope to locate the exact position of the object you want to look at. Adjust the orientation and make sure that the object is in the middle of the lens. 
  • Start with a low-power eyepiece. The next thing you want to do is attach a low power eyepiece to the telescope. If you do not have multiple eyepieces, use the eyepiece that your telescope came with. The ideal eyepiece to start with will be lower than 75x. Once you attach the eyepiece, look through the lens and verify that the terrestrial object is in your field of view.
  • Observe the object. Everything is now set up! Take some time to study the object you are looking at. 
  • Switch the eyepiece to a higher power lens. Now you can attach a higher power eyepiece to your telescope. Try to use an eyepiece that is over 75x. 

If you follow all of these steps, you should not have a problem using your refracting telescope. The most important thing to remember is to never look at the sun through the telescope. 

How Does It Compare to Other Telescope Types

How Does It Compare to Other Telescope Types

How do refracting telescopes compare to other models on the market? Let’s compare the refracting telescope to a reflecting and compound telescope.  


Reflecting Telescopes

Reflecting telescopes uses one mirror or a series of mirrors that are curved to reflect light and form a final, magnified image.

The main component is a primary mirror that is near the end of the main tube. This mirror reflects incoming light back to the focus of the telescope. 

Compound Telescopes

Compound telescopes are also called Catadiopritc telescopes. These models use both reflector and refracting technology.

More specifically, compound telescopes contain both reflective mirrors and refractive lenses. 


Reflector telescopes are typically less expensive than refracting telescopes. You can pick up a reflector telescope for around $300 to $500.

Refracting telescopes will cost around $500 to $1500 for a good quality model. 

Compound telescopes are also more affordable compared to refracting telescopes. You can buy a good compound telescope for $300 to $700.

Ease of Use

Depending on the model, all three telescopes are beginner-friendly. Out of the three different kinds of telescopes, the reflector telescope may be the most difficult. 

First of all, you will need to make a few more adjustments on the go with a reflector. Secondly, you may run into more issues when you are cleaning your reflector telescope.

It is rare to come across serious issues while performing maintenance on a refracting or compound telescope. 

Image Quality

Compared to refracting telescopes, a reflector telescope will have a higher image quality since you won’t experience chromatic aberration.

Chromatic aberration refers to the faint image distortion that occurs at high magnification powers.

Furthermore, reflector telescopes can capture more light than refractors can, leading to more detailed images. 


If you are mostly into astronomy, then a compound or reflecting telescope will be the way to go. However, refracting telescopes are mostly used for photography.

Due to its technology, refracting telescopes are ideal for astrophotography compared to simply using them for observation. 


We hope that this guide has helped you understand the refracting telescope. 

A refracting telescope is a type of telescope that allows you to observe terrestrial objects like the moon, planets such as Mars and Jupiter, and even double stars.

The instrument uses a series of lenses, the most prominent being the objective lens, to refract light and magnify an image of a faraway object.

There are a few main parts of a refracting telescope including the objective lens, the eyepiece lens, the telescope tube, the finderscope, and the mount and tripod. 

While refracting telescopes may seem complex, the instrument is beginner-friendly. To use the telescope, choose a location and set your tripod up.

Next, set up the finderscope, aim the telescope at an object, and use the finderscope to adjust your aim.

Once you have focused on the image, take your time and observe the object. 

Compared to other telescopes, refracting telescopes are typically more expensive. Much like other telescopes on the market, there are many beginner-friendly refracting telescopes to choose from.

Finally, refracting telescopes are best for those interested in astrophotography.