Combining the powers of both reflecting and refracting telescopes, catadioptrics use lenses and mirrors simultaneously in order to focus on celestial images. The most popular types are Schmidt-Cassegrain and Maksutov-Cassegrain respectively.
Given that they utilize more complex mechanisms, a catadioptric scope will cost you more than a standard one; the improved stability, increased aperture and more portability, generally, is definitely worth the investment, however.
As with most products these days, the market is flooded with options: some good, some mediocre and others just plain bad. That’s why we’ve assembled a list of five top telescopes, sure to put a smile on any stargazer’s face.
To discover more about how a catadioptric works, as well as the difference between a Schmidt and a Maksutov, have a look at our Buyer’s Guide. We’ve avoided jargon when writing up our research, for explanations everyday astronauts can understand.
If, after all that, you still have a question or two, don’t panic just yet. There’s also a handy set of FAQs right at the end, where we’ve answered the most common inquiries posed by fellow space explorers, so maybe yours is there too. Good luck!
Seeking Some Space ASAP? Here’s Our Top Pick:
OUR TOP PICK
Suitable for beginners and experts alike, Celestron’s NexStar 4SE is a computerized scope packed full of updated technology and the latest features. Easily distinguished by their iconic orange tube design, it will provide amazing stargazing opportunities.
With its 4 inch aperture, the primary mirror is more than capable of gathering enough light to accurately recreate celestial objects. A 1325mm focal length is longer than average, though the scope itself has a smaller than average footprint for portability.
Users are able to choose from a database of over 40,000 stars, clusters, nebulae, galaxies and more using the fully automatic GoTo mount, which locates and automatically tracks your intended object with incredible accuracy.
Thanks to Celestron’s SkyAlign technology, you can automatically align your scope against any three bright objects, enabling you to locate hundreds, if not thousands, of different stars. Taking away all of the effort, you’ll be ready to go in minutes!
Promising complete customer satisfaction, Celestron offers an unbeatable two year warranty, with unlimited access to their US based technical support experts. Based right in the heart of California, they’re an American manufacturer you can trust.
Pros
- Instantaneous alignment with SkyAlign software
- Fully automatic mount capable of finding over 40,000 celestial objects#
- Lightweight in spite of its considerable power
- Highest usable magnification of 241x
Cons
- Computerized tech makes for a much pricier telescope!
EDITORS CHOICE
Providing spectacular views, day or night, the 9823 telescope from Orion may be small enough to store on your bookshelf, but don’t underestimate it. Capable of producing images at the quality of scopes five times its size, it still packs a punch.
With an aperture of 102mm and a focal length of 1300mm, the focal ratio of f/12.75 makes for fantastic celestial views. You’ll be able to view bright deep sky objects, the moon, and the planets, as well as beautiful views of wildlife and nature in daylight.
As part of your purchase, you’ll also receive a 25mm Sirius Plossl magnification eyepiece, a 6x26 correct image finder scope and a 45 degree correct image diagonal. Each accessory will contribute to even more efficient space exploration.
Unfortunately, this scope does not come with a tripod, or with a mount. Given it costs more than the average model that includes both, we’d recommend that beginners aim for an option that features everything you’d need to get started.
What you will receive, however, is some Starry Night software, which serves as a desktop planetarium to help you map out the objects you’re looking at. Plus, a soft carry case to store everything in! For those with experience, it’s a great deal.
Pros
- Lightweight and highly portable - great for explorers
- Can be used in both light and dark conditions
- Additional Sirius Plossl eyepiece and correct-image diagonal included
- Free carry case and Starry Night software with every purchase
Cons
- Does not come with a tripod or a mount, which will need to be purchased separately
BEST VALUE
An excellent example of the Maksutov-Cassegrain from Sky Watcher is their Skymax telescope, with matched primary and secondary mirrors. Paired with an expertly coated corrector plate, prepare for contrast rich views, even in the blackest skies.
With a 102mm aperture and 2700mm focal length, the ratio of f/15 is impressive, especially when paired with the included 10mm and 25mm eyepieces also included. Plus, there’s a 90-degree star-diagonal, for even easier object tracking.
Promising a 95% reflectivity rating, the fully baffled tube ensures that stray light will never interfere with your viewing experience. A borosilicate primary mirror coated in aluminum delivers outstanding light transmission, every time
Using the red dot finder provided, locating objects and aligning your telescope towards them couldn’t be easier. Plus, the industry standard dovetail plate can be used with virtually any telescope mount, giving you endless choice.
Every single Skymax optical tube is equipped with internal primary mirror focusing; offering a wider than average focus range, you’ll be able to observe anything, from our very own moon to viewing deepest darkest space.
Pros
- Impressive aperture and focal length for the price
- Includes bonus 10mm and 24mm removable eyepieces
- Red dot finder and 90-degree diagonal included
- Compatible with just about any mount
Cons
- No tripod or mount provided - must be bought separately
RUNNER UP
Capturing the essence of a classic Schmidt-Cassegrain design is the CPC 100 from Celestron’s StarBright collection, utilizing their premium XLT optical coatings in order to reduce aberration as much as possible.
An aperture of 280mm and a focal length of 2800mm makes for a ratio of f/10, and the highest possible magnification of 661x. That’s far enough out to see the rings of Saturn, and they won’t just be a distant blurry smudge!
Thanks to their proprietary formula, you’ll certainly notice the difference with these coated lenses, which are capable of enhanced light transmission. For noticeably brighter, sharper images, look no further.
Built with a fully computerized, dual fork arm altazimuth mount, this baby has an internal GPS packed full of more than 40,000 celestial objects. Navigate the stars like a pro, even if you don’t have much experience in stargazing.
Ergonomically designed whilst remaining heavy duty, this tripod is so easy to assemble and attach to your scope, you’ll have no trouble doing it in the dark. Though it’s on the heavier side, it’s still portable enough to take out and about.
Pros
- Aperture 280mm, focal length 2800mm = decent f/10 ratio
- CPC GPS capabilities, with 40,000 objects to scan and find
- Computerized dual fork arm mount, ideal for beginners
- HD Pro wedge mounting for long exposure astrophotography
Cons
- On the very heavy side at 92lb - not one for the kids (unsupervised!)
RUNNER UP
Last but not least, we have a third and final offering from Celestron. What can you expect when they’re America’s number one telescope manufacturer? Their SkyProdigy 6 is a beautiful example of the Schmidt-Cassegrain design.
Combining an aperture of 152mm and a focal length of 1500mm, for an overall ratio of f/9.87, the highest possible magnification for this scope is 359x. Capable of viewing stars, moons and planets with ease, this is a seriously high tech product.
If you’re stressed about assembling a scope for the first time, worry not: the quick release fork arm mount and optical tube make for an incredibly easy set up. It’s simple, efficient and requires zero tools, so you’ll be up and running in minutes.
Offering everything a beginner needs to get started, you’ll find two eyepieces at 9mm and 25mm respectively, as well as a red dot finder and free Starry Night astronomy software included in box. This makes a great gift for a budding astronomer!
As it comes with its own sturdy stainless steel tripod, as well as several other useful accessories, this scope is on the expensive side. However, for seasoned astronomers, or newbies not hindered by a strict budget, it’s certainly worth it.
Pros
- Totally automatic alignment process for easy, quick location
- Computerized SkyProdigy mount with database of more than 4,000 celestial objects
- Integrated imaging camera automatically captures the sky for star identification
- Solid stainless steel tripod with built in accessory tray
Cons
- For such an expensive investment, customer reviews which indicate a few issues with alignment are concerning (but the majority of ratings are 5 stars)
Best Catadioptric Telescope Buying Guide
Catadioptrics 101 - What Are They?
Also known as compounds, a catadioptric telescope is an optical instrument that combines specifically shaped lenses and mirrors to form images. The intention behind them is avoiding errors that occur when using full lens or full mirror scopes.
Such errors are known as aberrations. In astronomy, this refers to the strange phenomenon in which celestial objects or beams of light are incorrectly displaced, appearing to move toward the direction in which the observer moves.
Typically, catadioptric scopes function by bringing together a spherical mirror, which can reflect light back on itself, in combination with a larger lens toward the front of the scope. This is known as a corrector, used to bend the light as it passes through.
As a result, they offer a much greater field of vision, able to use a folding optical path rather than a static one, which results in a more lightweight scope. This makes manufacturing easier, but the specialist lenses and mirrors used keep costs high.
Though many catadioptrics exist, the most prevalent and mass produced are the Schmidt Cassegrain and Maksutov Cassegrain. So named after the inventors of their respective corrector plates, they work in combination with Cassegrain reflectors.
The Schmidt corrector, first used in Bernhard Schmidt’s 1931 camera, was subsequently popularized in telescopes and mass produced in the 1960’s. Such designs swap out the Schmidt camera film holder for a secondary Cassegrain mirror.
Dmitri Maksutov also replaced the more complicated Schmidt corrector with a meniscus style, spherical lens with full aperture. In doing so, his design was able to correct spherical and chromatic aberrations, whilst staying true to the original.
Features To Consider:
Aperture
Any budding astronaut will tell you that a telescope’s aperture is perhaps the most important feature. Essentially referring to the diameter of the scope’s lens, it determines how much light it is able to gather, and therefore overall image quality.
A broader aperture is better, as this can allow you to see much further away objects in clearer detail, though that isn’t to say a more narrow telescope wouldn’t also work. Light conditions are also important when it comes to the clarity of images.
Focal Length
Also important when it comes to how far out you’ll be able to see is a telescope’s focal length. Referring to the length of the scope overall, this measurement divided by the aperture will provide your f/ratio.
By performing this calculation, you’ll be able to work out what level of magnification a particular scope offers. For instance, a focal length of 120mm and an aperture of 30mm provides an f ratio of f/4, for a magnification of 40x.
Finder
Essentially a smaller scope mounted on top of your bigger one, these viewfinders will enable you to find the celestial object you’re looking for much quicker. Nowadays, these usually incorporate a ‘red dot’, beamed into space for easier navigation.
All you have to do is look through the finder and move the telescope itself until the red dot (or another finding tool) is aligned with the object you’re looking at. For the purposes of sighting, you’ll want to keep both of your eyes open!
Tripod
Unless you’re sticking to handheld models only, you’re going to want to get a telescope with a dependable tripod. For those planning on intrepid exploration to get the best views, one that can stand up to uneven ground is even better.
Don’t just trust the manufacturer when they tell you their tripod is solid or sturdy. Of course they’re going to say that! Instead, consult the reviews from fellow customers in order to find out the true nature of its quality.
Portability
Again, those planning to stick to their backyards when stargazing don’t need to worry too much about this. It’s also worth mentioning that catadioptric scopes are also more lightweight by nature, as they consist of fewer parts and mechanisms.
However, you don’t want a telescope that’s impossible to transport, given that you may one day change your mind. Particularly for beginners, try to stick to a model that’s easily carried from A to B, and if it comes with its own travel bag, even better!
Best Catadioptric Telescope - FAQ's
What is the difference between Maksutov Cassegrain and Schmidt Cassegrain telescopes?
Whilst they work in the same way primarily, the main difference between Maksutov and Schmidt telescopes is the size of their corrector lens. This key piece, which is found in front of the secondary mirror, prevents the formation of aberrations.
In a Maksutov, you’ll typically see a thicker, spherical corrector lens, paired with an aluminum disc rather than a secondary mirror. Schmidt scopes tend to have thinner, more complexly designed corrector lens, used with the mirror as standard.
Likewise, Schmidt style telescopes will normally have a larger aperture (diameter of lens), where the Maksutov scopes employ a smaller, narrower design. Both, however, follow the same Cassegrain, catadioptric principles.
Which is best, reflecting or refracting telescopes?
The answer to this question depends on who you ask! When it comes to seeking out the deeper, darker reaches of space, it’s best to pick out a reflector, as these are better for checking out planets or closely examining the moon.
For picking up larger targets or multiple stars at once, say, a refractor is better, as they offer a much wider field of view in spite of their smaller apertures. Therefore, the best scope for you will depend on what you plan on looking at most frequently!
What kind of telescope is best for beginners?
First and foremost, you’ll want to opt for a telescope with a decent mount, as even the most powerful models will fail to function if they’re wobbly and unstable. This is especially true for beginners, who have less experience in positioning and locating.
Additionally, picking out a scope that comes with a decent finder will help you to navigate the wonders of space more easily. Those equipped with a red dot sight are especially helpful for pinpointing even the blurriest of clusters and nebulae.
Be careful not to spend too much money straight away. As a novice, many of the technological features that higher end telescopes come with will be useless to you, as you won’t be able to make use of them. A good quality, average scope is best.
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