For many people, Reflecting Telescopes are a dream instrument to have. Although it’s not like a simple mobile phone that you can use around, it’s an instrument that needs proper learning.
So, what exactly is a Telescope?
A Telescope is an optical instrument which the astronomers use to view distant and far away objects.
Principle of Telescope Working
A basic understanding of physics reveals that objects emit or absorb radiation – the telescope detects different objects’ presence by their ability to detect, absorb, or reflect Electromagnetic radiations.
To add to your surprise, if you use a telescope of higher magnification, you can view other planets as well. Isn’t it amazing?
Importance of Mirrors in Reflecting Telescope
The most essential components in the telescope are the mirrors that collect and converge the light. The older telescopes used curved and clear glass lenses.
However, modern telescopes employ slightly curved mirrors that converge the light from different objects. It’s mostly the mirror that decides how the light concentrates and what we view from the telescope.
Optics of a Telescope
In terms of telescopy, we call the mirrors or lenses the “optics.” The optics are lighter in weight that makes the telescopes more favorable to use.
It solely depends on the magnification power of the optics that how good a telescope will work. The bigger and powerful optics will view even the very dim objects and objects that are really distant.
The logic behind this is that the larger mirror, lenses, or what we call them “optics,” gather more light than the smaller ones. Hence, the more the light, the better we will have the picture of the distant objects.
Generally, there are two types of optics that further determine the types of Telescopes:
- Refractor Optics or Lenses
- Reflector Optics or Mirrors
Types of Telescopes on the Basis of their Optics
The Following are the basic types of telescopes:
The telescopes have lenses as their optics are known as Refracting Telescopes.
Every one of us has once in our lifetime read or studied the principle of refraction. Let’s recall it here. In a Refracting telescope, we have a pair of lenses that focus the light, and the objects appear closer than they really are.
The lenses are ‘Convex shaped,’ which makes them particularly useful in converging (or gathering) the light. Unlike the concave lens, which bends the light away from one point (diverge), the convex lens turns the light inward and converge all the rays at one point.
Refractor telescopes are best to observe and view Earthly objects or things.
Advantages of Refracting Telescope
- Once they are perfectly aligned, Refractor telescopes do not misalign easily.
- The lens’s inner surface does not need cleaning very often, as it does not come in contact with the atmospheric air.
- The air, humidity, and temperature changes do not affect the results as the tube is totally sealed.
In Reflecting telescopes, we employ mirrors instead of the available lenses. A reflecting telescope is more preferred because of the higher efficiency of the mirrors. The Mirrors – do not refract the light – instead, they “reflect” the light. Hence, we use concave mirrors here.
As the light passes through the concave mirrors, the mirrors reflect it as it is – without bending. As we know, the mirrors flip the images upside down – hence, we have to use another mirror to flip it back again to view the upright image.
Reflecting Telescopes are employed to view far off objects that are faint and deep in the sky.
Advantages of Reflecting Telescope
- There are no chances of chromatic aberration in reflecting telescopes.
- Reflector telescopes are more comfortable and cheaper to build and maintain.
- Only one side of the reflector telescope is critical for efficient working.
Preference for Reflecting Telescope
Astronomers usually prefer the Reflecting Telescopes for a number of reasons. Some of these reasons are:
- A lens is very thick and heavier in weight. Hence, it gets challenging to gather and collect light.
- Lenses are complicated to manufacture, and any slightest scratch can result in distorted images.
- A mirror is usually very thin – even the bigger mirrors do not have to be considerably thick.
- The mirrors are lighter, so they make reflecting microscopes easier to use.
- The mirrors are super easier to clean and polish.
Moreover, as we speak of it, it is far more convenient to make a mirror than to make a lens that fulfills telescopy’s purpose. Hence, to overcome the problems, astronomers usually prefer Reflecting or Mirror telescopes than the refracting ones.
The type of telescopes with both the reflector and refractor optics present within the same assembly is called Catadioptric Telescopes. Hence, these are also known as the Compound Telescopes.
The catadioptric telescopes are best for Astrophotography. However, they might require more frequent maintenance and alignment as compared to the typical refractor telescopes.
Handling of a Telescope
The telescope is not just like an ordinary computer that you would change when it gets some damage. Hence, you have to take special care of it, particularly when you are traveling. It’s a fact that you will have to travel with them to different areas to view distant objects.
- You must have a designated carrier bag for your telescope and all its accessories.
- Keep the unit in a shock-free area to avoid any damage to the lens.
- Be very careful when cleaning the telescope. Make sure to avoid using your hands.
- Use lens tissues, solutions, surgical cotton, or compressed gas for cleaning the optics.
- It is highly unrecommended that you disassemble the unit very often. It contains very delicate parts that may be hard or impossible to align once disassembled.
- Do not directly look at the sun with your telescope.
All these Telescopes have their own significance and importance. However, it solely depends on you what purpose you need it for. If you have an interest in astronomy, you should go with a Compound or a Reflecting telescope.
However, if you want to view Earth objects such as birds, clouds, or buildings, you might want to go with a refracting telescope. Although a reflecting telescope is generally preferred, it isn’t easy to maintain. Hence, it will be best if you consider using a refracting telescope.