Maksutov-Cassegrain telescopes are extremely compact, low-maintenance telescopes that are ideal for travel telescopes as well as planetary viewing/imaging. Their simplicity in manufacturing leads to sharp optics with minimal need for collimation, and their long focal ratios enable great performance with even the cheapest eyepieces.
Advantages & Disadvantages of Maksutov-Cassegrain Telescopes
Maksutov-Cassegrain telescopes use a spherical primary mirror and a thick meniscus corrector lens that is spherical on both surfaces and has an aluminized reflective “spot” on the back surface that functions as the telescope’s secondary mirror. The convex secondary mirror gives them a “folded” optical design, and the all-spherical surfaces of these telescopes are easy to manufacture to high tolerances. Because the secondary mirror and corrector are built into the same piece of glass, collimation is rarely required in most Maksutovs. As a result, Maksutov-Cassegrain telescopes are incredibly sharp on small targets like the Moon, planets, and double stars; it’s extremely rare to see one with bad optics.
Behind apochromatic refractors, Maksutov-Cassegrains easily cost the most per inch of aperture of any telescope type. They are rarely made with apertures larger than 7-8 inches, and the thick corrector plates on larger Maksutovs can slow down the time it takes to cool down. Many Maksutovs are limited to 1.25”-only accessories, and almost all have focal ratios of f/12 to f/15 or above, severely limiting their field of view and keeping them boxed in at high magnifications with most eyepieces. Most Maksutovs also use a moving-mirror focuser like a Schmidt-Cassegrain telescope, where the primary mirror slides on a metal rod adjusted at the back end, moving the focal plane without physically elongating the back of the telescope. This usually works well but can have “image shift” when focusing, which can be a bit of a pain at high magnifications or when trying to do astrophotography. You won’t be doing deep-sky astrophotography with a Maksutov-Cassegrain due to the super-long focal ratio and limited field, but planets and the Moon are possible.
Things to Look For
Any good Maksutov-Cassegrain usually has some kind of visual back which can be removed. Some scopes have “flip mirror” assemblies, which are often plastic and low-quality; replacing them if the flip mirror is damaged, gets stuck, or is bad optically can be a pain. If possible, stick with a scope that takes a standard astronomical star diagonal.
Best Maksutov-Cassegrain Telescopes: Our Recommendations
Under $200: SarBlue Mak60 with Dobsonian Mount
The SarBlue Mak60 comes in several variants, but the tabletop Dobsonian-mounted package is easily the best one. This telescope is extremely compact, able to fit in a small backpack or handbag and with an optical tube hardly any bigger than a large beverage can. A decent medium-power eyepiece, star diagonal, and finder are also provided. The Mak60’s small aperture, however, quickly runs out of steam on targets besides the Moon and bright planets; the limited field of view, low resolution and minimal light-gathering ability put a bottleneck on what you can actually see.
$200-$300: Orion StarMax 90
The StarMax 90 shares much of the basic design and features as the SarBlue Mak60, but has significantly larger aperture and a true 1.25” rear port allowing for the use of wide-field 1.25” eyepieces without vignetting. It’s still extremely compact and easily fits in a backpack, but has more than double the light gathering ability and 50% more resolution than the tiny Mak60, though 90mm is still quite small for a serious telescope. The StarMax 90 includes a red dot finder, high-quality 1.25” prism star diagonal, and two 1.25” Kellner eyepieces yielding 62.5x and 115x respectively. You can also attach the StarMax 90’s base to a sturdy photo tripod if you wish thanks to the threads on the bottom.
$300-$450: Sky-Watcher Virtuoso 90
The Virtuoso 90 is optically more or less identical to the StarMax 90 and features an alt-azimuth mount that can be used on a table top or attached to a tripod. However, the Virtuoso 90 adds automatic motorized tracking (albeit not GoTo) to its mount and includes a solar filter as well as a pair of eyepieces, a star diagonal, and a 5×24 finder scope. The Virtuoso 90’s motorized tracking is a huge help for planetary observing but doesn’t have the cumbersome setup of aligning a full GoTo system which is arguably unnecessary for such a small telescope anyway.
$450-$650: Celestron Astro Fi 102 Mak GoTo
The Astro Fi 102 is a fully motorized GoTo telescope with a full-sized free standing tripod, larger 102mm (4”) optics and the mount is controlled exclusively via your smartphone or tablet with Celestron’s SkyPortal app or another app like SkySafari Pro. The Astro Fi 102 is quick to set up and get to observing with, includes a pair of decent eyepieces, and the dismantled telescope packs up into a fairly small package able to fit in a suitcase or small storage container. While it might not seem like much, the extra ½” of aperture the Astro Fi 102 has over a 90mm Maksutov does wonders for brightness and resolving power.
$650-$750: Celestron NexStar 127SLT
The NexStar 127SLT is actually only 120mm in aperture due to its stopped-down internal parts, but it still features 38% more light gathering ability than a 102mm Maksutov (78% more than a 90mm) and slightly more resolving power. The 127SLT is controlled with an old-fashioned hand paddle unlike many newer GoTo instruments but the SLT mount is built similarly to the Astro-Fi mount and fairly easy to use, offering a huge database of objects with fully motorized tracking and slewing capabilities – a WiFi adapter can also be purchased separately to control the telescope with your smartphone/tablet if you wish.
$750-$1000: Sky-Watcher Skymax 127
The Skymax 127 features the same optical tube as the Celestron NexStar 127SLT, but paired with the more advanced and compact AZ-GTi mount from Sky-Watcher. The AZ-GTi can be used manually or as a GoTo mount without affecting alignment while pushing the telescope around the sky by hand (unlike the GoTo mounts from Celestron) and is also controlled via your smartphone/tablet with the free SynScan app or another app such as SkySafari Pro. The AZ-GTi mount can easily accept a variety of telescopes and even be converted to an equatorial mount with some additional accessories if you desire.
$1000+: Explore Scientific FirstLight 152mm Mak-Cassegrain Telescope with Twilight I Mount
The FirstLight 152mm Mak is fairly unique in its use of a 2” Crayford focuser on the back instead of an internal moving-mirror focusing system. The external focuser design eliminates the problems of image shift and mirror flop, which is particularly nice for imaging purposes. There are also tube rings and a carry handle instead of a simple bolted-on dovetail which makes carrying the telescope a bit more convenient. This version of the FirstLight 152mm package comes with Explore Scientific’s all-manual Twilight I mount, which is easy to set up and use, rock-steady and has slow-motion manual adjustments to easily track objects in the night sky by hand. The standard Vixen-style dovetail on the FirstLight 152mm Mak makes it easy to put it on an equatorial mount with tracking if you desire and the Twilight I likewise will accept a variety of other telescope optical tubes.
$2500+: Celestron Advanced VX 700 Maksutov-Cassegrain
The Advanced VX mount is packed with features for astrophotography and is of course a fully motorized GoTo mount. The huge 180mm Maksutov-Cassegrain optical tube offered by Celestron and Sky-Watcher offers unparalleled lunar and planetary views as well as the potential to be used for some excellent astrophotography work; award-winning lunar photographer Robert Reeves uses one of the telescopes. However, the 2700mm focal length is outright claustrophobic, especially given that the telescope can’t really illuminate the field of a 2” eyepiece, and for the price you could get a C9.25 or C8 Schmidt-Cassegrain with comparable portability but better deep-sky views. The thickness of the Maksutov corrector in such a large instrument also begins to hinder cooldown time and makes this scope quite heavy; with a total weight of 75 lbs it’s hardly a portable or convenient instrument the way smaller Maksutovs tend to be.
- $300-$400: Explore FirstLight 100mm Mak-Cassegrain with Twilight Nano Mount
The 100mm FirstLight Maksutov is excellent optically, and the Twilight Nano suffices as a mount, but its lack of fine adjustments is a bit of a nuisance, and the included accessories with this telescope are very low-quality.
- $300-$400: Explore FirstLight 100mm Mak-Cassegrain with EQ3 Mount
The EQ3 mount provides more fine adjustment for easily tracking the sky with the 100mm Firstlight Maksutov and can be motorized for automatic tracking if you wish. However, it’s not the easiest to set up nor does it have the steadiest design, and the included accessories are, of course, still terrible.
- $400-$600: Explore FirstLight 127mm Mak-Cassegrain Telescope with EQ3 Mount
The EQ3 mount is capable of supporting the 127mm FirstLight Maksutov, but it’s hardly the most stable or easy-to-use combination, with poor-quality accessories being the norm as with the other FirstLight telescope models.
- $400-$600: Celestron NexStar 90SLT
The NexStar 90SLT is nice enough, but for the price, you could get the Astro-Fi 102, which has a larger aperture and an easier-to-use mount interface. And at 90mm of aperture, there’s really no need for a GoTo telescope, and the Virtuoso 90 or StarMax 90 probably make a lot more sense if you’d prefer to stick on the small side.
- $600-$700: Sky-Watcher 102 mm Skymax AZ-GTi Mak GoTo
The 102mm Skymax AZ-GTi package is a great telescope with an incredibly versatile and easy-to-use mount and decent accessories. However, the only advantage over the cheaper Astro-Fi 102 is that this telescope can be aimed manually, which may or may not matter enough to you to justify the additional expense. And if you’re spending more, why not go for the 127mm model?
- $600-$700: Celestron NexStar 4SE
The NexStar 4SE uses the same optics as the Astro-Fi 102mm and Skymax 102. However, an annoying built-in flip mirror of lower quality than standard 1.25” star diagonals is permanently affixed to the back of the tube, the mount is rather heavy and bulky, and for the price, the Astro-Fi 102 and Skymax 102 are available and both are significantly more portable and offer more features.
- $700-$800: Explore FirstLight 127mm Mak-Cassegrain Telescope with Twilight I Mount
The 127mm FirstLight Maksutov is an excellent telescope, and the Twilight I is a rock-solid, high-quality alt-azimuth mount. Unfortunately, the price is the same as several computerized 127mm options, and the included accessories are of poor quality, making this combination a poor value proposition at best.