The word telescope conjures up images of tall, pointy towers with a giant lens at the top. However, the telescope is actually a type of optical instrument designed to capture light. The earliest known telescopes date back to the early 1600s. These early versions were not much more than tubes and lenses that, combined, could capture an image of an object on the other side of a room. Modern telescopes have advanced substantially over the years. Many different kinds of telescopes are used for specific purposes and in specific circumstances. Here are some common types of telescopes that you should know about if you want to learn more about this optical device and its various uses.

Reflecting telescope

A reflecting telescope uses a large mirror inside a long tube to capture and focus light. These telescopes are known for their wide field of view. This means the telescope can capture a wide swath of the night sky. The images from a reflecting telescope are not as bright as other telescope types, but they are more detailed and come with a higher resolution. Reflecting telescopes are also easy to use and relatively low cost. The biggest drawback of the reflecting telescope is that it needs a long tube with a large mirror. This makes the telescope very large and difficult to transport. Reflecting telescopes are best used in wide-open spaces, like deserts, where there is little interference from light pollution.

Reflecting Telescope with An Infrared Camera

Some astronomers use a reflecting telescope with an infrared camera. The infrared camera allows the telescope to see objects in the distant universe that the human eye cannot see. The infrared camera can see through clouds and red lights emitted by objects in the universe that are very far away. Infrared light is invisible to the human eye. The reflecting telescope with an infrared camera is a specialized tool that can be used to discover and learn more about astronomical phenomena that are very far away but cannot be seen with a typical telescope.

Optical Telescope

The optical telescope has mirrors at the end of the tube, but the primary focus is on the lenses. The lenses inside the telescope focus the light so that you can see a magnified image of the object you are observing. The optical telescope is the most common type of telescope today. Most of the telescopes that are sold for amateur and professional use are optical telescopes. Like the reflecting telescope, the optical telescope comes in optical and reflecting varieties. Optical telescopes come with a wide range of magnifications and can be used for various purposes. Some optical telescopes are portable enough to be used for stargazing. Other large optical telescopes are used on the ground or in space for more advanced purposes, like observing the planets or distant galaxies.

Dobsonian Telescope

The Dobsonian telescope is a reflector telescope with a very simple design. The tube and the base are of a single piece of wood. The primary mirror is very large, and the central axis has a very little correction. This makes the Dobsonian a very inexpensive telescope. While the Dobsonian telescope is cheap, it has a very high optical quality and is a very strong and durable piece of equipment. Because of its simplicity, the telescope is easy to use and requires no special skill or knowledge. The simplicity of the Dobsonian telescope also means that you can build your own. It is an ideal telescope for amateur astronomers who want a high-quality telescope but do not want to spend a great deal of money.

Cassegrain Reflecting Telescope

The Cassegrain reflecting telescope is a much more advanced version of the reflecting telescope. This type of reflecting telescope has two mirrors. The primary mirror is placed at the end of a long, narrow tube. Light enters the tube and bounces off this primary mirror, moves down to a smaller secondary mirror at the bottom of the tube, and then back up to a focus point. This type of reflecting telescope has a wide field of view and very high image quality. The Cassegrain reflecting telescope is very expensive and not easy to build. This type of reflecting telescope is most often used in professional observatories.

Stellar Observatory

The stellar observatory is specifically designed for studying stars. It is most often used in space. The stellar observatory consists of a large telescope that is connected to an optical spectrometer. The telescope focuses light from the stars onto the spectrometer so that the astronomer can study the chemical composition of the stars. The stellar observatory is a very advanced telescope that is used to study the stars in great detail. It is a very large and expensive telescope, but it enables astronomers to see and learn things about the stars that they could not learn using smaller, less advanced telescopes.

Telescopes are a long-standing optical instrument that can be traced back to the early 1600s. The telescope comes in various types: reflecting, optical and stellar observatories. Regardless of the type, they all function by collecting and focusing light. What started out as a simple tool to allow people to see objects that are far away has become a high-tech instrument used for several different purposes.

Other interesting reads 

Buying your first telescope

Basic Telescope Types(External Link)