The three types of telescopes that you are likely to be able to access and operate are of the optical variety. There is the refractor telescope, the reflector telescope, and then the compound telescope that makes use of a combination of both of the first two’s methods. Unless you are a professional and/or very serious astronomer, you may never have the opportunity to operate a non-optical telescope (e.g., radio telescope).
Telescopes have had a prodigious history with the first patent being filed in the Netherlands all the way back 1608 and have most certainly have been in use before then although the originator is as elusive as the mysteries of the universe that fascinate us. Telescopes have been used for navigation and sighting things on distant shores by pirates and other maritime travelers, and then other times they are used for looking deep into space in order to challenge our eyes to something bigger than ourselves and see the unimaginable.
These optical varieties generally all use what is already in the visible portion of the electromagnetic spectrum, but they differ in how that light is focused (the type of objective) and presented to you. The refractor type uses lenses to accomplish this. This objective lens is coordinated with an eyepiece so that whatever is being looked at will be amplified enough and gather more detail for you to see. These type of telescopes were very popular well into the late 19th century, and they may be good for historical purposes or if one is looking for a cheaper tool, then this might be a good option. However, the diameter of the lens (known as the aperture) is what determines much of a telescope’s power, and the next two types of telescopes allow for a larger one.
The difference in a reflector version is that it uses mirrors in order to achieve the amplification that is done with a lens in the previous type. There might be multiple ones or just a single mirror, but in any case, these eponymous reflectors are curved in order to get a detailed image to your eye. One of the advantages of this type is that it does not produce the same chromatic aberrations that the refractors are known for, but there are still newly introduced focus issues depending on the total quality of the device.
Probably the greatest improvement of these over the older variety is that they allow for a much greater aperture so that these telescopes can be of a higher power in many cases. That is one of the reasons that they are practically ubiquitous when it comes to astronomy and the research within that field.
The compound telescope does as its name implies and uses both mirrors and lenses in order to bring the amplified and improved image to your eye. They are also known as catadioptric as opposed to catoptric for those with mirrors only. They are excellent at allowing you to focus and adjust the error correction so that the field of view is aberration free for a wider expanse than the two aforementioned types that might be found in stores. The reflectors are basically able to utilize the refractors as corrects on the aberrations produced and vice versa.
This design allows for a couple of complication saving processes when it comes to the manufacturing, and they are also generally able to be much lighter in weight. Both of these factors mean that this easy of manufacture can often be passed on to the consumer who is looking to purchase one that will provide an excellent viewing experience while still remaining in the range of a reasonable budget.
The compound telescope does as its name implies and uses both. This just about sums up the basic three types of telescopes that you are likely to encounter when you first begin to delve into the exciting field. After that, there are many different subtypes and varieties that can be looked through depending on the direction the field takes you in the coming future.
Want to know more? Be sure to check out our comprehensive Telescope 101 Guide for more information about all aspects of telescopes, including history, construction, components, plus care and maintenance tips.
If you’re wondering if binoculars can be used for astronomy, be sure to check out our article that delves into the possibility of viewing the stars and planets above with astronomy binoculars.