If you are a beginner and you just started looking for telescopes to buy, you’ll find out that there are different types of telescopes. This might make you think “how many types of telescopes are there?” or “What are the different types of telescopes?“. Well, in this article you will find the answer to this question in detail.
There are 3 main types of telescopes. The first is a Refractor telescope. The second is a Reflector telescope. And the third is a Catadioptric telescope or you can say Compound telescope.
You might come across other types, such as Dobsonian, Schmidt-Cassegrain, or Maksutov-Cassegrain, they all come under one of these main three types. Whether a telescope is large or small these are the main types in which telescopes are classified.
We will look at each type and see how they are different from each other.
Refractor Type Telescope
Refractor telescopes are simple ones. It is a stereotype of how a telescope looks. It has a long tube with a lens at the front and an eyepiece at the back. As this telescope deals with refraction they are also known as dioptric telescopes. A properly designed refractor telescope gives better and sharper images.
As refractor telescope uses lenses instead of mirrors, it becomes very expensive to manufacture bigger aperture refractor telescopes.
Usually, you will find most refractor telescopes with an aperture size of 4 inches or lower. The majority of the telescopes which has less than a 4-inch aperture are refractor telescopes.
Refractor telescopes are good for observing the moon and the planets which will give super-sharp images. As this telescope uses lenses they hardly need any alignment and you can start using it as soon as you open it from the box. The small-sized refractors are true “grab-n-go” telescopes.
The only disadvantage of refractor telescopes is apochromatic aberrations. These aberrations can be removed by using secondary lenses or by using filters.
Reflector Type Telescope
One of the biggest problems with the refractor telescope is that the cost of a bigger aperture is too much. So this problem is solved by reflector telescopes.
These telescopes use a mirror to gather and focus light. The most common reflector we know is the Newtonian reflector. It is called the Newtonian reflector because it was invented by Sir Isaac Newton.
This type of telescope has a slightly curved concave mirror at the bottom of the tube, which collects light. The collected light is reflected at the top, where a secondary mirror directs this light to an eyepiece.
Dobsonian telescope
One of the most important parts of the telescope is its aperture & if you want the biggest aperture for the money you spend, then the reflector is the telescope you should go for. One of the most common reflector telescope types you’ll find is a Dobsonian telescope. These telescopes give excellent performance for the price you pay for.
The refractor telescope does not need any collimation or adjustment. However, you’ll need to collimate the reflector telescope once in a while.
Catadioptric Type Telescope
Catadioptric is a branch of optics where you deal with mirrors and lenses at the same time. So all the catadioptric telescopes use the best of the refractor and the reflector telescope to form an image. That’s why it’s called a compound or a catadioptric telescope. The biggest plus point of these telescopes is they are very compact and lightweight. The telescopes which come under these categories are Schmidt Cassegrain or Maksutov Cassegrain-type telescopes.
As these telescopes are compact they are lightweight. Because of this, you can get a bigger aperture telescope that is easily transportable. Due to its compactness, the mount of the telescope is also not heavy. That’s why many of these small-sized catadioptric telescopes are kind of grab & go-type telescopes. Like reflector telescopes, catadioptric telescopes also need occasional collimation.
Costs
When you compare the cost of these telescopes it lies between the reflector and refractor types of telescope.
For example.
If you want to buy an 8-inch refractor telescope then it would probably cost you around $8000+. The most important is you need to find someone who manufactures a bigger aperture refractor telescope.
If you want to buy the same 8-inch reflector telescope it will cost you probably $800 – $1200.
If you want to buy the same 8-inch catadioptric telescope then it will cost you around $1200-$2500.
So this is how various telescopes are classified into the main three types. If you want to buy, then check out this article.
We hope you understood the difference between the different types of telescopes to make a better buying decision. If it helped, then please share this article with someone who is interested in astronomy and space stuff.
