What is a refractor telescope?

What is a refractor telescope?

Refractor telescopes

It’s easy to look at different telescopes and assume that they all work in the same way. While that is partly true, the mechanics on the inside is what matters the most.

For example, it is almost impossible to tell a refractor telescope from a reflector telescope by simply looking at the tube, yet the two kinds of telescopes use different components to bring the night sky into view.

Different types of telescopes

How a refractor is different from other telescopes

Typically, there are three types of telescopes that budding astronomers use, with a refractor telescope the preferred for beginner or amateur viewers.

They were the first kind of telescope developed, and their history goes as far back as the 1600s. Their operating principle is relatively simple. There is a curved lens at one end to focus the light down the tube. The inside is coated with a dark substance to increase efficiency. On the other end, there is another lens that magnifies the image. This lens is called the eyepiece.

Refractor telescopes excel at viewing objects within our own solar system, such as the moon, Mars or Jupiter. However, the lenses can struggle with the faint light of distant objects, which won’t produce a clear image.

The other two types of telescopes are:

Reflector: Uses one or a series of curved mirrors to project the light to form a magnified image. These are often referred to as Newtonian telescopes and are lighter than refractor telescopes. Reflector telescopes are best for viewing deep-sky objects several light-years away.
Compound: Uses a combination of elements from refractor and reflector telescopes such as a glass lens with a mirror to produce the visuals. Also called catadioptric telescopes, these are the most modern in astronomy and have short, stubby tubes. As a result, they have a higher magnification range and, due to their construction, allow for more light to enter the tube.

Digital vs. mechanical

When you envision a telescope, most people will think of a mechanical model that uses lenses or mirrors. There are no moving parts on the inside of the tube, and you must manually adjust the focus by turning a knob. A digital telescope is a highly advanced gadget that takes care of all things for you. It incorporates low-light sensors, an onboard computer, and an integrated battery to adjust the visuals automatically. The disadvantage of a digital telescope is that there is no eyepiece to look through. Instead, you and others wirelessly connect to the telescope and view space objects through your mobile device.

Accessories for better viewing

Motorized GoTo mount

It’s great to peer into deep space from your backyard, but finding nebulas, clusters or planets can be challenging. A motorized GoTo mount makes it easier — this is an attached telescope tube that can automatically turn and tilt to align with an object.

This is handled by a controller where you can cycle through different celestial bodies. After calibrating its precise location, the motorized mount faces the eyepiece toward the object.

Smartphone eyepiece for photography

Once you figure out where your favorite planet or constellation is, you’ll want to snap a photo to show friends. But the standard eyepiece that comes with any telescope makes this difficult. Unfortunately, the eyepiece isn’t built for photography, but luckily you don’t need to buy a new one.

While they are commercially available, many telescopes come with a smartphone adapter. The mobile device clips into it the same way as a dash mount, and then you slide the adapter’s eyepiece into the diagonal mirror.

Best refractor telescopes

Celestron NexStar 102SLT Computerized Telescope

This telescope tube attaches to the motorized GoTo mount to automatically turn toward one of the 40,000 stars, galaxies and nebulae in its database. The Celestron telescope has a 102-millimeter aperture and comes with two eyepieces and a red dot StarPointer finderscope.

Unistellar eVscope eQuinox Smart Digital Refractor Telescope

This digital telescope has a built-in low-light sensor, an onboard computer and a built-in battery. There is no eyepiece as you connect to the telescope through Bluetooth and view the images on a mobile device. It is 100 times more potent than a regular telescope.

Gskyer Astronomical Refractor Telescope for Beginners

Perfect for taking photos of planets, this telescope comes with a smartphone adapter for astrophotography. It has a 600-millimeter focal length and 90-millimeter aperture and comes with three eyepieces.

Prices listed reflect time and date of publication and are subject to change.

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