Difference Between Reflecting and Refracting Telescopes

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What is the difference between refracting and reflecting telescopes? If you’re a star-lover, then you’ll know that these two telescopes can both bring the night sky closer to you but in very unique ways. They work by increasing the amount of visible light to make dim objects more visible in the sky.

Here’s a quick guide on the difference between reflecting and refracting telescopes and how they work.

What Are Reflector Telescopes?

A reflector telescope has an open-ended design with a curved mirror at the base of the tube. This is known as the primary mirror and its job is to collect light from the night sky so it can reflect it onto the second flat mirror on the other end of the tube.

The focuser is where the eyepiece is and it eliminates the need for a diagonal mirror.

In a Newtonian reflector, for instance, light enters from the left-hand side and travels to the inner mirror on the right-hand side. From here it goes back to the eyepiece opposite the optical cube.

Thanks to the reflector design, this type of telescope lead to an inverted image which makes it unusable during the day because it would show everything hanging upside down. But, it’s perfect for astronomy purposes.

What Are Refractor Telescopes?

Refractor telescopes are characterized by a front-facing curved lens which works by using the optical tube to bend and concentrate light on a specific point.

As such, it works similarly to a pirate’s spyglass because you could place an eyepiece in front of the light. But if the telescope were directed at the sky while the eyepiece sits at the end of the tube, you’d have to kneel to get a look at what you’re trying to view.

Astronomical refractor telescopes are especially unique because they can bend light at a 90-degree using a diagonal. This allows you to position the eyepiece properly. That’s because you must diagonally insert the eyepiece. Daytime diagonals typically use a 45-degree angle, while astronomy diagonals are at a 90-degree angle. This is known as the “star diagonal.”

When you look at an image through the lens of a diagonal, the left and right hemispheres will be reversed, but the up and down positions are correct. Since space doesn’t have any left or right directions, this small detail doesn’t matter.

If you plan to use your refractor for daytime boat viewing, you can always fix this problem with a prism, which is how binoculars and spotting scopes are created.

What is the Difference Between Refracting and Reflecting Telescopes?

The main difference between a reflecting and refracting telescope lies in how they work to magnify the image by manipulating light. A reflecting telescope is primarily made up of a mirror that bounces off the light onto a smaller focus area.

A refracting telescope, on the other hand, focuses light from one end to another using lens. Refracting telescopes were big in the old world because they were easy to produce with the available technology of that time.

But, this also means that this type of telescope has some inherent design limitations like the need to make glass lenses that don’t have any foreign materials in them.

This is extremely difficult to do when working with large lenses. On the other hand, it’s much easier to make the reflecting mirrors required to make a reflecting telescope.

Reflecting telescopes are also great because you can make them any size you want. The lenses have a one-meter size limit due to the design flaws mention in the previous paragraph.

You can make reflecting telescopes as big as you like because there are no inherent design limitations to deal with. You can make little mirrors and then put them together to make one large model or build large arrays for the fraction of the cost of a refracting telescope.

Reflecting telescopes are popular due to their versatility and the fact that they’re cheap to make. Aside from their step price, refracting telescopes introduced many challenges, such as presenting distorted images caused by the material used or lens weight.

Refracting and reflecting telescopes each have their unique uses. Reflecting telescopes are more useful for astronomy because they allow you to see clearly across farther distances, whereas refracting telescopes are designed for everyday applications such as the use within camera lens systems.


Truth be told, both reflecting and refracting telescopes are useful and beneficial. Both offer exceptional value for money and versatility. Depending on the specific provider you choose to purchase from, you may even have access to different packages to choose from.

Keep in mind that the higher your aperture, the more stuff you’ll be able to perceive in the night sky. Extra aperture allows you to magnify the image and see it in more detail. However, this also means that the larger the aperture, the pricier it is to make the telescope and the bigger your budget has to be.

If your goal is to learn collimation with a 4-inch scope or less, then you’ll do well with a refractor. They’re always quite rugged and easy to use, which makes them ideal to take with on family vacations. They can easily fit into your carry-on luggage.

Add a correct-image diagonal at a 45-degree angle, and you’ve got yourself the perfect daytime spotting scope. For nighttime viewing, you can just use the 90-degree star diagonal instead. Using these two image diagonals might add to the weight, but it’ll give you a more versatile experience as well.

A reflector is probably your best bet if you’re looking for a telescope that’s bigger than 4 inches. For a cost-effective option, look into the Newtonian design, whose specs tick all the boxes without breaking the bank.

When paired with a Dobsonian mount, this type of reflector offers a comprehensive solution. It’s easy to use, steady and versatile. The Newtonian/Dobsonian design is very popular for “star viewing parties.”

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