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Shop for Telescopes: Our Telescopes Organized by Optical Design
There are at least three major types of telescope available today, as well as a number of variations on those themes. "Why so many?" you may ask. A telescope is basically a tool, and different tools are sometimes needed to perform different tasks. We advise buyers to answer a few simple questions about what the telescope will be used for and how it will be used before contemplating a choice.
Which type of telescope is the best? There is no simple answer to that question until you define your expectations of the telescope. Some telescope types allow for both terrestrial and lunar / planetary observing. Others are mainly intended for observing distant galaxies and other deep space objects, and may be completely unsuitable for terrestrial use. The images and brief descriptions below will start you on your way to understanding these different design types and their applications. If this is your first telescope and you find yourself a bit overwhelmed, you may want to start with some simple advice at the bottom of this page.
Refractors are generally the most expensive type of telescope available, and they are also the best for certain limited applications.
Dobsonian telescopes offer the most aperture for your dollar, and aperture is the most important factor when viewing deep space objects.
Schmidt-Cassegrain telescopes represent a compromise between large aperture and compact design. They are the most popular design we sell.
The Aplanatic Schmidt-Cassegrain is a derivative of the standard Schmidt-Cassegrain design that substantially reduces coma. This can be highly advantageous when imaging with today's larger format CCD cameras, but the difference is also visibly noticeable.
Maksutov-Cassegrains telescopes are similar to Schmidt-Cassegrains, using both mirrors and a lens to focus light. Maksutov-Cassegrains offer superior contrast to Schmidt-Cassegrains and are excellent telescopes for planetary and double star observing.
Solar telescopes by Coronado, Daystar, and Lunt Solar Systems allow you to safely observe the Sun in Hydrogen-Alpha and Calcium-K wavelengths.
Newtonian reflector telescopes are an alternative optical design that use mirrors to focus light into a smaller area. Most of the larger telescopes in use today rely on mirrors because it is prohibitively expensive to produce large lenses.
Maksutov-Newtonian telescopes are a form of catadioptric telescope that uses both mirrors and lenses to bring light into focus. Mak-Newts perform similarly to high quality refractors, allowing both very low and very high magnifications.
Telescope optical tubes may be purchased separately to be combined with the mount of your choice. This practice is often the norm with Apochromatic Refractors, but is also popular with Schmidt-Cassegrains and their derivatives.
Advice for First Time Telescope Buyers
Are you thinking of buying your first telescope? Telescopes are basically tools for making things look closer. There are different types of telescopes available that are optimized for different purposes. The most important steps in deciding which type of telescope to buy is determining how it will be used and what it will be used for. We suggest that you stop to ask the following questions about your expectations of this first telescope before proceeding further:
- What do you hope to see with the telescope? If your application is strictly daylight terrestrial observing, then what you may really need is a Spotting Scope. If your real interest is astronomy, then you need to ask a few more questions:
- Will you be satisfied with just the moon and planets?
- Does your passion include deep space objects such as star clusters, nebulae and distant galaxies?
- Would you favor a dual purpose instrument that also allows you to observe birds and other wildlife or boats out on the water?
Please read the brief descriptions on our main telescope page, which provide a quick introduction to what each type of telescope is best suited for. - Does the telescope need to be portable enough to transport to a dark site? This is often essential for urban dwellers who want to observe deep space objects. All of the telescopes on our website have specifications listed towards the bottom of their individual descriptions. We encourage you to look at these in order to better understand the size and weight of the instrument you will be setting up and taking down every time you observe. Some types of telescopes are inherently more portable than others. We are often asked to sell telescopes for our customers, and the number one reason for this is that the telescope turned out to be too large or heavy for frequent use. Don't buy more telescope than you can comfortably handle.
- Are you the type of person who has the patience to track down celestial targets on your own, or do you require the assistance of a computerized "go-to" telescope to locate objects for you? If you are a beginner or live in a highly light polluted urban environment, then a go-to telescope may well be your best option. Go-to capability is a function of the telescope mount, and generally speaking, almost all telescope types are available with or without a go-to mount. More seasoned observers and those who have access to very dark skies may not need or want go-to capability, but we think it is a good idea for most beginners.
The answers to these questions will start to narrow your choices considerably. We also highly recommend the Advice for Beginners written by Ed Ting, amateur astronomer and contributing editor for Sky and Telescope magazine. And by all means feel free to give us a call for some friendly and honest advice.
Skies Unlimited was founded in 2004 with the object of making the telescope buying experience both easier and more enjoyable. Our staff of real amateur astronomers actually use the telescopes and accessories we sell and can give you honest advice on their suitability for your particular needs. At Skies Unlimited we offer a broad selection, including used telescopes, all at low prices and with practical honest advice. If you are unable to find the answers you need here, then by all means give us a call.
More Reading on Telescopes
Those of you with a real thirst for knowledge with respect to telescopes, both amateur and professional, may want to start Wikipedia's broad based coverage of the topic, including many links to other articles, at wikipedia.org/wiki/Telescope. Keep in mind that you do not need to know how telescope optics work in order to enjoy them.
NASA maintains a website dedicated to the Hubble Space Telescope at www.nasa.gov/hubble/. This website includes the history and technical details of the telescope, as well as a gallery of images. Please keep in mind that the Hubble telescope is much larger than any amateur telescope and that it is not encumbered by the negative effects of the Earth's atmosphere. Hubble images will invariably be better than what can be seen with an amateur telescope, but the experience is just not the same as seeing an object with your own telescope.
