We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

How Do I Choose the Best Cassegrain Telescope?

By G. Wiesen
Updated May 17, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

If you are interested in a Cassegrain telescope, there are a number of different aspects to look at and consider before making a purchase. One of the first things you should look at is the aperture size of the telescope, as well as its focal length. Though there are a few different types of Cassegrain telescopes, these differences are fairly minor and not likely to impact amateur usage. You should look for a Cassegrain telescope with the right combination of power and size for your needs, and consider a mounting system that is sturdy and includes a “GoTo” interface.

A Cassegrain telescope is a type of catadioptic telescope, a telescope that uses multiple mirrors or lenses, first developed in 17th century France by the man from whom it takes its name. The basic construction is quite simple, and allows these telescopes to have impressive focal lengths despite small tube lengths. These telescopes typically have two internal mirrors within the tube and an eyepiece at the far end of the telescope. Light enters the end of the telescope and reaches a concave reflector at the bottom of the tube; the light is then reflected back toward the open end but is focused onto a small mirror within the tube that reflects the light back toward an opening in the primary lens so the light can reach an eyepiece.

As you consider the best Cassegrain telescope for your needs, you should typically begin with the aperture size. This is usually the size of the primary reflector in the tube, which has a tremendous impact on how much light is gathered by the telescope and on its maximum magnification, so you should look for as large an aperture size as possible. The maximum magnification for a telescope is basically its aperture size in inches multiplied by 50, or the size in millimeters multiplied by two.

A Cassegrain telescope’s focal length also has an impact on the magnification and the quality of the images you can see through it. You should look for as large a focal length as possible, while still keeping the tube itself to a reasonable length. Though larger telescopes are often better than smaller ones, you should be sure to choose a telescope you can actually use in a reliable way. Smaller telescopes are typically easier to transport and set up, so unless you have a permanent observation point, you should choose a telescope that is small enough for you to easily set up and use.

You should also consider the type of mounting or stand you can use with any Cassegrain telescope you choose. While some telescopes come with a stand, many are sold individually and you may end up spending as much on a good telescope tripod as you do on the telescope itself. You should consider a Cassegrain telescope with a stand that features a “GoTo” system. This is an automated computer system that allows you to quickly and easily aim your telescope toward a selected object in the night sky.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.