How do Telescopes Work

A telescope is a complex tool used by astronomers to spectate distant objects in the sky; the practice of using a telescope has been around for years. Only recently, certain amendments have been made, and simple telescopes have been transformed into more complex and hybrid ones. The basic laws of physics that oblige here in the working of a telescope are related to light. Curved mirrors are used in various sets and orientations to gather and focus on a particular object’s light. You might be wondering that how do telescopes work actually, right? Well, we got you covered! 

Main types and how do telescopes work?

There are two different deviations or flavors of telescope that you see nowadays;

  •         Refractor telescope (lens are used in here)
  •         Reflector telescope (it uses mirrors)

The telescope’s main objective is to see the faraway objects more transparently and subtly; the mirrors or lenses used within the telescope can even brighten up some of the dimmest objects. To answer the question, how telescopes work? Consider the following scenario as it will better help to understand how it works;

Why can’t you read something that is written on a billboard far away from your original position, it appears small and all dim, and you can’t read the text at all? Why? Because being that far away, the text doesn’t take as much space on your retina, which also happens to be extremely small. Having a big enough eye or a telescope for that matter will significantly collect more light from the text etched on the billboard and magnify it enough so that your retina can have more pixels to process. Following is a brief difference between the raw materials that are used in the building of various telescopes and the significance that these bring to the table.

What lenses do?

If you were wondering, how do optical telescopes work? Then you are about to find out. A telescope that uses a lens is known as a refracting telescope. It works as simply as an eyeglass does. It bends the light that passes from it and makes things brighter and more apparent than these are. This is the reason why afar things seem closer than ever when viewed from a telescope. If you want to consider more distant objects in the sky that appear to be dim, you would have to use a bigger and heavier lens. Just like a heavy lens used in glasses that people wear. The bigger is better and evidently more powerful.  

The refracting telescopes can only work too much because where the need to see more distant objects arises, the lens has to become heavier, and it becomes difficult to hold it into place. Not only this, but it stops a lot of light passing through it. This is where the refracting telescope finds its limitations because to see farthest objects, the lens’s surface needs to be smooth, and with heavy lenses, this is something that can’t be done. The image will look significantly blur and purely out of focus.     

Why mirrors are a better option?

Those interrogating how do reflecting telescopes work? Now will be able to find a reasonable argument here. When a telescope is made up of mirrors as the central piece, it is known as a reflecting telescope. The light is concentrated by ricocheting from the mirror. That is why all it matters for the mirror to have is the perfectly curved shape; else doesn’t matter much. It can be bigger or smaller. Mirrors have a smooth surface and can make even the most obsolete and far away objects brighter and nearer. That is why it is way easier to develop a large mirror than to develop a large lens. The only difference between the two is that the lens gets heavier when made big, but the mirror presents with specific maneuverability even when it is big that a lens can’t.

But mirrors have their own problems; as a matter of fact, the reflection telescopes produce inverted images. To resolve the issue, another lens of the same power needs to be fitted near to the eyepiece. So, the initially inverted image can be reversed back for you to have a clear and erect picture. One of the most endearing benefits of using mirrors is that these are not heavy at all, and for that same reason, can be launched into space.    

How do Mirrors work in telescopes?    

There are two particular pieces on a telescope that make it happen, and it also effectively explain how do mirrors work in telescopes;

  • The objective lens collects enough light from an object that is distant and then brings that light or image into a proper focus that is brighter and reveals all aspects of the object so the naked eye can easily perceive them.
  • On the other hand, the eyepiece (from where the image is seen from the telescope) takes the bright light. This light is coming from the source (lens or mirror depending on the type of telescope used). It then magnifies it for our eyes to process the image as the object seems exceptionally near.

This is the same principle a magnifying glass works on, taking light from the object and then spreading it out for the retina to perceive the image as brighter and crystal as it can be. So, this is the detailed working of a telescope, there are many factors at play here, and you need to determine your needs or project that you are working on to discern between the type of telescope to engage yourself.


So, this is the detailed working of a telescope. There are a lot of factors at play here, and you need to determine your needs or project that you are working on to discern between the type of telescope to engage yourself with. It is probably best to buy reflecting telescopes as setting them up is more straightforward, and results are almost imminent on a lighter note.