Telescopes can range in price from under $200
to tens of thousands. Naturally, only the top professionals and scientific institutions are going to shell out more than $10k for a telescope. But that doesn’t mean that the average person looking to explore the heavens should be left out.
Luckily, the consumer and professional class of telescopes is meant exactly for the average person to the advanced hobbyist. These telescopes are equipped with the useful tools and features you need to take your hobby to the next level, finding, tracking, and observing different celestial bodies.
But these telescopes are also built to fit into the average person’s budget. Telescopes in this class bridge the gap between professional astronomy tools and the telescopes used for beginners to get started with. They represent the best all-around value and will provide you with a great tool to expand your knowledge and love of astronomy.
1. Refractor Telescopes
Refractor telescopes are built with lenses that refract light and send it along a focal path within the telescope tube. An eyepiece captures the light at its focal point, creating the image you see within. Below are 4 types of refractor scopes and their common uses.
2. Achromatic Telescopes
A refractor telescope gathers light at every wavelength, but not all wavelengths have the same focal length inside the telescope tube. This creates chromatic aberration, a sort of fuzziness around the outside of the object you’re viewing as the light waves scatter toward the edges. An achromatic telescope uses a special lens made by combining Flint glass and Crown glass to achieve different light dispersion, correcting these aberrations.
3. Apochromatic Telescopes
Like an achromatic telescope, an apochromatic telescope uses a special lens to correct chromatic aberration. The apochromatic lens differs in that it disperses three wavelengths at a time instead of two. While apochromats contain the same glass as the achromatic lens, they typically also contain liquid between the lenses for added dispersion.
4. Superachromat Telescopes
Like the apochromatic and achromatic lenses, a superachromat corrects aberrations by bringing different colors into focus at the same time. The superachromat is quartic, meaning it disperses four colors simultaneously. These highly fine-tuned lenses are built with expensive fluorite glass to achieve the best type of image correction.
An inexpensive telescope produced for the 2009 International Year of Astronomy, a Galileoscope is a refractor scope built to bring astronomy to the masses. It is versatile enough to use with various eyepieces to enhance magnification, and economical enough for kids and amateur enthusiasts. Its narrow field of view and 17x magnification are meant to parallel the kind of telescope Galileo would have used, in effect harnessing the astronomy of the past to bring new interest to the field. The best part is, they come in a kit so you can build them yourself.
6. Keplerian Telescopes
Invented in 1611 by Johannes Kepler, the Keplerian telescope uses convex lenses to widen the field of view from Galileo’s concave lens prototype. While Kepler’s invention meant higher magnification strength for telescopes, it also inverted the image.
7. Reflector Telescopes
A reflector telescope is built with mirrors that elongate the focal path of the light entering it. This style was invented by Sir Isaac Newton in the 1680s and became popular due to its enhanced image clarity.
8. Newtonian Reflector
Isaac Newton’s original invention from 1668, and the basis for most reflector telescopes developed since. Light enters through a parabolic or spherical primary mirror, which bounces the light back up the telescope to a secondary plane mirror, when then sends the light to the eyepiece at a 90-degree angle. Because they are optically “fast,” they tend to be much shorter than a refractor. The absence of lenses also solves the problem of chromatic aberration.
RELATED: we also reviewed Dobsonian telescopes here. (these are very close to Newtonian reflectors)
9. Cassegrain Reflector Telescopes
A Cassegrain reflector telescope uses a series of concave and convex mirrors to fold the light path to enhance its focal length and improve magnification. A hole in the center of the primary, parabolic mirror sends light to the eyepiece.
10. Catadioptric Telescopes
The marriage of catoptric and dioptric (refractor and reflector) engineering is the catadioptric telescope. This combination is the best of both worlds, providing mirrors and lenses that better correct aberrations and provide a wider field of view. Their method of folding the light path within the telescope tube means faster optics and a shorter device.
11. Schmidt-Cassegrain Telescopes
A catadioptric telescope that uses spherical mirrors and corrector plates to prevent spherical aberration. Their focal path is long, but their field of view is narrow, perfect for observing planets or for deep-sky viewing. Most catadioptric telescopes are derivatives of the Schmidt-Cassegrain telescope, or SCT.
12. Infrared Telescopes
Infrared telescopes must be in a dry, high altitude environment to detect infrared space radiation without interference. These telescopes are used to gather information about our universe’s history. Because light travels for so long before it reaches Earth, it has had time to become detectable infrared radiation. This radiation dates back to the beginning of the universe, providing insights into the vast history of the cosmos.