A telescope is an item used to view things that are far away; it makes distant objects appear magnified. Below are several types of telescopes.
- Refractor telescopes
This is also called a reflecting telescope and is built with lenses that refract light. The refractor uses a single or combination of curved mirrors reflecting light to form an image; the refractor also has an eyepiece that captures light at a focal point. This is a telescope that has been there since the 17th century, and it was invented by someone known as Isaac Newton, Reflectors were used mostly for astronomy research because of its excellent design of reflecting work in the broader spectrum of light.
- Achromatic telescopes
Unlike the other telescopes, achromatic gathers light at every wavelength, and in this case, lenses target the different wavelength lights to several points. It has the blue and the red light; the blue light is focused closer compared to the red light. This telescope has an exceptional lens which is made by combining two glasses, the Flint and the grown glass; the reason for using the two glasses is that it helps achieve different dispersions of light and corrects aberrations.
- Apochromatic telescope
This is different from the chromatic telescope because their lenses differ; the apochromatic lens disperses three wavelengths, unlike the achromatic, which has two lenses. They have the same glass as the achromatic lens, but they are a bit unique because they have a liquid in between the lenses to help improve dispersion.
This telescope has a third lens, has a normal consideration that is positive and 2 Flint’s. It has several colors, but the red, green, and blue light are brought to a single focus leaving out other colors.
A cheap telescope that can be used by several eyepieces because of its versatility. An eyepiece is used for magnification; it’s very easy to build this kind of telescope yourself because it comes in a kit. Galileoscope is made up of the telescope tube, the modern eyepiece, which is the larger lens, the Galilean eyepiece, which is the smaller lens, the ring cap, and the Barlow tube.
- Kaplerian Telescopes
Johannes Kepler invented it, and it uses lenses known as convex. This lens widens the field of view because of its arrangement; it has excellent magnification strength. In this case, the convex lens is used as an eyepiece instead of concaved ones. Kaplerian telescope does not focus at the same place. You need to adjust it differently to get a clear image. This telescope does not magnify images, but it gives a larger field of view.
- Reflector telescopes
It’s built with mirrors that gather and focuses light; this telescope has a parabolic shape that focuses parallel light rays into one point. Reflector telescopes do not suffer chromatic aberration because all wavelengths do not reflect the mirror, they are cheaper to make compared to refractors, objective mirrors can be made very big because it’s a long the backside.
- Newtonian Reflector
It was invented by Isaac Newton and is a classic mirror telescope design. This is one of the telescopes which have no lens; the absence of the lens is advantageous because it solves chromatic aberration problems. Here is how it works, light enters through a mirror either spherical or parabolic, the mirror then bounces the light back up the telescope to another mirror (secondary) it then sends the light to the eyepiece.
One of its major advantages is its price; it’s the price. It is affordable compared to other telescopes and refractors. You can get this telescope easily because of the low price.
- Liquid mirror telescope
Most telescopes use a glass mirror, but the liquid mirror uses a rotating dish with highly reflective liquid, for instance, Mercury. Mercury is poured in a rotating dish when the dish rotates; there are two forces created inertia and gravity.
Gravity works by pulling down the liquid surface while on the other end, inertia pulls the liquid sideways. When the liquid is disturbed, it will return to its original state. Liquid mirror telescope has a relatively low cost.
- Three mirror anastigmat telescopes
It has three parabolic mirrors to correct aberrations, only one mirror corrects spherical aberrations, but when they are three, they can work well by eliminating the other two aberrations. The three aberrations to be eliminated are coma, spherical, and astigmatism.
- Catadioptric Telescopes
This telescope can produce images at a far distance. It uses refractive optics and reflective optics; the refractive optics is lenses while reflective are mirrors. Using both mirrors and lenses is essential because it boosts performance. There are several types of catadioptric telescope designs, and this is; Schmidt -Newtonian, Schmidt-autograph, Maksutov-Cassegrain, and Schmidt-Cassegrain.
- Infrared telescopes
For this telescope to work well, it should be kept in a dry high altitude environment. It has a combination of mirrors and lenses, these two gathers radiation and focuses it on a detector, and the data produced is translated by a computer into useful information. You might be asking yourself what a detector is; it is simply made up of digital devices.
The infrared telescope is able to detect cool objects, and apart from that, it has longer wavelengths than the visible light. This telescope is too faint, and it can’t be observed in visible light.
- Ultraviolet Telescopes
They are used to view things that are so far away, such as distant planets and stars. UV telescopes have helped us learn a lot about the stars; they have been used to study winds from hot stars that are still informing process, hot dead stars.
You can have clear observations when using this telescope because it’s not affected by the atmosphere. There is no limitation in using it at night because it’s simply perfect. Apart from the good side of it, it has a few disadvantages too.
UV’s are expensive to build and position in place, some of the telescopes like the Hubble space are hard to image the moon because it’s too sensitive to light and can’t image something that’s in the sun’s direction and to add in that maintaining it is too difficult.