A Rudimentary Guide to Refractive Telescopes

Perhaps the oldest type of telescope is the refracting telescope that has been in use since the early 15th century. The design was good and has been improved upon since then but essentially a refracting telescope is still a refracting telescope.

The refractor has a set of convex lenses that allow the images presented to the viewer to take on a larger shape and be bigger and brighter to the perspective of the viewer. This makes them especially useful for viewing the stars, planets and other celestial bodies.

The telescopes are made up of a series of convex lenses that feed an image through an eyepiece lens much like you would find in a set of binoculars. These harness the principles of refraction to bend light and better view distant objects. This has allowed for many great observations of the night sky. While their design may seem complex, the idea is fairly simplistic and just requires a few properly shaped lenses.

There are also various versions of the refracting telescope that have been invented and popularized for different reasons. The Galilean telescope is named after the famous scientist whose insights into the universe challenged the “truths” of his time. This was one of the first refracting telescopes in history. The Keplerian refractor was also named after another noteworthy man of science which changed the Galilean concave eyepiece to a convex eyepiece.

The various designs and styles would be changed and improved much over the next few centuries. The achromatic refractor would be introduced in the mid-16th century with the more impressive apochromatic refractors being invented years after.

COMPARE: Reflector telescopes are composed of mirrors whereas refractor telescopes are only made of lenses (Source: Vaonis).

Pros and Cons of Refractor Telescopes

As the technology that supports the refractor telescope continues to evolve, there have been many advancements made in the telescope. While the technology continues to advance, the issue of size has become a problem. The fact is after a certain size, the telescope will have a greater chance of defects in the construction that retard the function and performance.

There are other issues too.

  • Impressive contrast and sharpness
  • Light and transportable
  • Closed tube = protection against humidity and dust
  • Maintenance and cleaning almost nonexistent
  • Small diameter = less light collected
  • Chromatic aberrations
  • Higher price

Source: Vaonis

While we are not sure how the refracting telescope will advance from here, we do know that many of the world’s greatest achievements were visualized through a refracting eyepiece. This type of telescope has been in use for centuries and will continue to do so as the years continue.

No matter which type of telescope you choose to use, you are sure to have a unique view of your neighbourhood and the universe. Never forget the importance of the famed refractor and how much our word has benefitted from the brilliant design.

Originally written for celestialworld.co.uk.

Image by Szőcs Tamás – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7138040

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