What is Telescope and How Does it Work?

We all were curious about what was happening in the sky during our childhood. We used to be awestruck by the animated pictures of stars, moon, galaxies, sun, and the entire solar system. Many of us are still mystified by the things far away in the sky. There is a tool that can ease our curiosity about planets and galaxies. This tool is called a telescope. Read along with me to learn what is telescope and how does it work.  

You must be eager to know about this tool in detail. Lend me your ears as it will be informative and exciting reading for you!


1. What is a Telescope?

A telescope is an optical instrument that employs curved lenses and mirrors to magnify the image of far-away objects through involving various phenomena, including reflection, refraction, absorption, emission, electromagnetic radiations, etc.

The Italian astronomer Galileo became the first person to develop the first practical refracting telescope in the early 17th century with a curious mind. Since then, several technologies and efforts have been put into the thought “WHAT IS A TELESCOPE” to enhance the structure and efficiency of this tool.

2. Components of a Telescope:

There are 6 essential components of a telescope given a brief view as follows:

  • Eyepiece: The most important component of a telescope that enhances the clarity of the image and provides safety to the ocular lens from falls and damage is the eyepiece.
  • Lenses: Most refractive telescopes include two biconcave lenses, one of which is an eyepiece lens and the other is an objective lens.
  • Mirror: To enhance the quality and improve the position of the image, most of the reflecting telescopes and some massive refracting telescopes involve two mirrors in their structure. The shape of the mirror varies from planar, parabolic, hyperbolic or spherical depending upon the telescope’s design.
  • Structural support: High power telescopes require some support like a tripod stand to mount to rotate the telescopic axis in the horizontal or vertical direction.
  • Telescope tube: With a diameter of almost 8 inches. The telescope tube comprises the body of a telescope. It also assists in adjusting the focal length with the help of a knob available downside.
  • Finderscope: The finder scope is a small telescope attached to the main telescope tube with a broader field of view and relatively lower magnification. Its main function is to estimate the location of the target object to be viewed.

3. Important Features of a Telescope

  • The most important feature is the ability of a telescope to collect light. It mainly depends on the size of the aperture that assists in constructing a clear image. Larger the aperture, the better is the focused image.
  • Another important feature is the wavelength of the telescope. A high-quality telescope has a wavelength of about 1/8 or less.

4. Essential Telescope Accessories

Like any gadget or machine, telescopes also need accessories. And for this, we have compiled a list of some of the accessories that will help to turn your scope into a complete system.

  • Single-power finders
  • Finder scopes
  • Lights and magnifiers
  • Storage cases
  • Batteries and power supplies
  • Protective scope covers
  • Focusers
  • Clocks
  • Fans and SCT coolers
  • Observing chairs and ladders

5. Types of Telescopes

There are many different types of telescopes employed by astronomers for different purposes. The main types of telescopes are as follows:

(1) Optical Telescopes

  • Refracting Telescope




  • Reflecting telescope

Cassegrain Telescope

Newtonian telescope

  • Catadioptric Telescopes

Maksutov–Cassegrain telescope

(2) Non-optical Telescopes

X-Ray and Gamma-Ray Telescope

6. Difference between Monocular and Binoculars

In addition to outdoor sightseeing and adventures to professional activities, monoculars and binoculars efficiently serve the purpose. The selection between two requires a descriptive understanding of both devices.

  • Monocular: With the size of a palm, monoculars are the smallest and simplest telescopes used to see distant objects with one eye. Although their viewing efficiency is far less than high power telescopes, they are handy to see otherwise blurry objects.
  • Binoculars: In contrast to monoculars, binoculars comprise two viewing tubes. Binoculars have some advanced features than monoculars, like night vision.

Magnification specifications of both monocular and binoculars are almost identical but different from those of a high-power telescope. 

7. Working Principle of the Telescope

The main function is to gather light from celestial bodies at one point to form a clear image of distant bright objects.

After seeing a telescope, the first question that arises in a viewer’s mind is, “how does a telescope work?” The telescope works through constructing an inverted, virtual, and magnified image (at least distance of distinct vision) of the target object to be resolved, present at some specific distance from the objective lens.

8. Final Thoughts

Astronomers have come a long way from a mere thought of “what is a telescope” to today’s most efficient and quick telescope variants! From observing celestial bodies, collecting accurate data, and analyzing the image, there are so many magics this tool is capable of.  APEXEL is one of the leading manufacturers, delivering the best telescopes for all-purpose use. Their specialized team of engineers brings together various key areas of expertise and makes sure to deliver modern optic services and solutions. Connect with APEXEL to know more about this visual tool in detail!

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