When you are getting introduced to the telescopes for the first time, you might find two major types of telescopes, reflectors, and refractors. They are different from each other only for their building process and the method they are using.
The reflector telescope is mainly designed using mirrors to focus light on distant objects whereas the refractor telescope only uses lenses for focusing method, not mirrors. And this method of using two different components created a lot of differences between them.
Today we are going to reveal which telescope is more or less durable, which one gives the best performance, what optical quality they provide, which is suitable for a beginner or a pro, and some other things including tips. Stay with us, learn the differences elaborately.
Definition and focusing method
Before going through the features and making differences between the two, the first question may arise in your mind, “What is a reflector telescope?” Well, a reflector telescope is an optical instrument using two mirrors to focus on the celestial objects. It's also known as a Newtonian telescope.
In a reflector telescope, the light coming from a distant object directly goes through the optical tube. Then the first reflection occurs on the primary mirror located at the bottom of the tube. The major part of a reflector is the primary mirror. Then it passes the light towards the eyepiece in which we keep our eyes. There is a secondary mirror located near the top of the optical tube. This mirror reflects the light for the second time and makes the object visual to the observers.
Mirrors in a reflector telescope
You have just known what a reflector telescope is and how it works. Now let's see the optical quality of the mirrors at a glance.
- Made with a hyperbolic or parabolic or spherical primary mirror.
- Hyperbolic mirrors can give the perfect view of the stars but they are more expensive than the latter two. So manufacturers stopped using these types of mirrors.
- It's a very simple and low cost to make reflector telescopes using parabolic mirrors.
- But while using a parabolic mirror in a telescope, the coma aberration causes the deformation of the objects. So the spherical one is more preferable.
- The spherical mirrors are being manufactured mostly as they can perfectly focus and show the best views.
Using a reflector telescope
Knowing a telescope isn't similar to using one. As the primary or secondary mirrors are openly settled in a reflector, there is a chance that the mirrors might get dirty after a few days. And if it continues, the mirrors become less reflective within a year. So the mirrors should be manipulated carefully. Usually, in this case, the users don't want to take any risk. They just clean the mirrors frequently so that a reflecting telescope can be used for a long time.
Along with the cleaning process, a reflector telescope needs to be collimated so that you can adjust yourself with the alignment of your telescope. And this collimation should be done before you get prepared for an observation whether it's an astrophotography session or wildlife viewing.
- Gives the best view with a larger screen
- Relatively cheaper
- Easy building procedure
- The wavelengths reflect on the mirror in the same way and that's why chromatic aberration doesn't occur.
- Collimation procedure seems to be a little hard
- Mirror cleaning requirement
Definition and focusing method
A refractor telescope is an optical instrument that is scientifically designed with lenses to produce clearer images. There are two lenses in a refractor: the objective lens(larger), the eyepiece lens(smaller). The objective lens is for focusing whereas the eyepiece is for viewing. Let's know the focusing method of a refractor telescope:
First, the light created from an object passes through the optical tube and refracts on the front lens. Then it goes to the eyepiece holder where an eyepiece or a camera is settled. Now the view becomes clearer to the observer.
The optical system of a refractor
The refractor telescope can produce sharper images than a reflector telescope. The optical system of a refractor is of high quality. And for its extraordinary features of sharpness and contrast, it becomes popular to the astronomers. In the meantime, there are some defects too. Some refractors contain only one lens for which they can't create brighter images. So in this case, you need to choose a refractor capable of using two lenses.
Refractor in Astrophotography
Instead of not having high lighting capability, the beginners in astrophotography want to use a refractor telescope. You know why? Because they want more compact and durable images than a lot of light. There is a key feature that can select only the wavelength on the lenses and remove the ultraviolet light. Despite all of these qualities, this refracting telescope is not heavier and easy to carry anywhere. And thus a refractor is most preferable for the skywatchers who want to enjoy the starry night with a lightweight, portable and simple telescope.
- Transportable and lightweight
- Not necessary to clean or manipulate
- Incredible sharpness with great contrast
- No chance to be dirty as the tube is closed
- Not enough light collected
Reflectors vs Refractors at a Glance
Though we have explained the two telescopes separately and clarified all the differences above, still this section is arranged for you so that you can see only the principle differences at a glance:
|Reflector telescope||Refractor telescope|
|1.Works with mirrors||1.Works through lenses|
|2. Low cost and easy building method||2.Higher price with complexity|
|3. The cleaning procedure is required for open tube||3. No need to clean as the tube is closed|
|4. Collimation should be done||4. Collimation isn't required at all|
|5. A larger screen and brighter images||5. Smaller screen but sharper images|
|6. Heavier to carry||6. Lightweight and easy to carry|
|7. The capacity for collecting better light||7. Can't collect much light|
|8. No chromatic aberration||8. Chromatic aberration occurs|
|9. Optical quality is often disappointing||9. Stable optical quality|
|10. Preferred by amateur astrophotographers||10. Preferred by the experienced astronomers|
Some things to remember:
- The larger of a reflector telescope's primary mirror, the brighter the objects
- In some cases, the large mirrors can create optical aberrations.
- Need to collimate a Newtonian telescope before each of an observation
- To collect a large amount of light, clean the reflector telescope mirrors frequently
- Use a second lens in a refractor to avoid the optical defects
If you can differentiate a telescope from another, you can easily decide which one will be appropriate for you to enjoy the night sky. And for making your celestial journey easier and quicker, we showed the differences in detail. Let us know what you are thinking right now. If you have any curiosity or interest to know, feel free to ask us. We would be pleased to have your opinions.