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Orion StarMax 90mm Review – Partially Recommended

The Orion StarMax 90mm Tabletop is an ill-suited combination of an otherwise acceptable telescope and mount, priced way too high for the level of build quality or performance it offers.
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When you read one of my reviews at TelescopicWatch, you can trust that not only have I gotten to use the product, but I’ve compared it to numerous others and tinkered with it down to the literal nuts and bolts. When I'm not writing reviews, I'm out under the night sky with my own homemade or modified telescopes, with over 7 years of hands-on experience in astronomy, having owned 430 telescopes myself, of which 20 I built entirely.

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Score Breakdown

Optics: 5/5

Focuser: 5/5

Mount: 3/5

Moon & Planets: 5/5

Rich Field: 2/5

Accessories: 5/5

Ease of use: 4/5

Portability: 5/5

Value: 3/5

Read our scoring methodology here

A good telescope needs to have a good mount with capability that matches what the telescope is designed to use. Unfortunately, Orion’s StarMax 90mm Tabletop completely and utterly falls short of this. There are good reasons why the StarMax 90mm Tabletop is the only catadioptric telescope out there sold on a tabletop mount without slow-motion controls or motors. The StarMax 90mm Tabletop is a great scope optically but gets frustrating to use due to its long focal length, stubby tube, and lack of any fine pointing adjustments. The recent decline in the build quality of this telescope, owing to Orion’s switch of suppliers, means that it’s even harder for us to recommend.

If you want a small Maksutov-Cassegrain, we’d recommend one with a mount that offers manual slow-motion controls or motorized tracking, features that the StarMax 90mm Tabletop lacks. Our top pick in the 90mm range is the Sky-Watcher Virtuoso 90, a tabletop 90mm Mak like the StarMax but with a tracking mount, better build quality, and an included solar filter too.

Orion StarMax 90mm

How It Stacks Up

Ranks #9 of 29 ~$200 telescopes






Orion Starmax 90 Maksutov


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Best Similar Featured Alternative: Sky-Watcher Virtuoso 90

What We Like

  • Great optics
  • Very easy to use
  • Fast setup time

What We Don't Like

  • Small aperture
  • Narrow field of view
  • Low-quality build and accessories
Partially Recommended

The StarMax 90mm Tabletop is not a terrible telescope, but it would’ve been nice if the designers had put a little more thought into it.

The Optical Tube Of Starmax 90mm

You might be forgiven at first for thinking the StarMax 90mm Tabletop is related to or derived from the Virtuoso 90 or C90 from Sky-Watcher/Celestron. For a long time, the StarMax 90mm Tabletop was indeed the same telescope as those two. I was surprised to learn recently that due to Orion’s ongoing divorce with Synta (the parent of Sky-Watcher and Celestron and formerly a large supplier of Orion), they have cheapened the scope and its accessories. The StarMax 90mm Tabletop now has a largely plastic build, including the exterior of the tube itself. The present-day StarMax 90mm Tabletop seems to be made by JOC/Bresser, who are also the OEM for Explore Scientific telescopes and many of Orion’s other offerings nowadays.

StarMax 90 before the 2023 update

Fortunately, the optics at the heart of the StarMax 90mm Tabletop haven’t changed. It’s still a 90mm (3.5 inch) f/13.9 Maksutov-Cassegrain telescope with a 1250mm focal length. The Maksutov-Cassegrain design uses a spherical, concave primary mirror with a spherical meniscus corrector lens. The StarMax 90 and the majority of other mass-produced Maks use the Gregory-Maksutov design, which has a secondary mirror that is simply an aluminized portion of the corrector’s back. Maksutov-Cassegrain telescopes have fairly lenient manufacturing and alignment tolerances because they only have three surfaces on two pieces of glass to worry about, and all of them are spherical curves. As a result, they produce world-class images for their aperture. The StarMax 90mm Tabletop is no exception, with sharp stars across the periphery of its (relatively narrow) field of view.

Light path of Gregorian Maksutov Cassegrain
Gregory-Mak Light Path

Focusing the StarMax 90mm Tabletop is done the same way as with most other catadioptrics; the primary mirror moves up and down the tube on a shaft when you turn the knob at the back end. Your star diagonal/eyepieces or other accessories attach to a visual back or “eyepiece holder” which screws onto threads at the back end of the tube and doesn’t move when you adjust focus. The StarMax 90mm Tabletop is too small to suffer from much “image shift” – the apparent wobble of the view that can happen if the primary mirror rocks on its support as it travels back and forth.

The StarMax 90mm Tabletop has 3 hex head collimation screws for adjusting the primary mirror which can be used to collimate the scope if need be, though Maksutov-Cassegrains rarely, if ever, fall out of collimation. These screws are recessed at the back of the telescope and push on an assembly between the rear of the tube and the primary mirror; they should be firmly tightened, and only small adjustments are needed to fix any miscollimation of the telescope.

The 1.25” visual back attached to the StarMax 90mm Tabletop is not the same as a Schmidt-Cassegrain visual back – though adapters are available to attach such – but it has built-in T-threads to attach your DSLR and use the telescope as a long focal length telephoto lens. The 1.25”-only format of this telescope and its long 1250mm focal length mean the maximum field of view you can get with the StarMax 90mm Tabletop is about 1.3°, or two and a half times the angular diameter of the full Moon or Sun in the sky.

Like many other telescopes, the StarMax 90mm Tabletop’s optical tube has a Vixen dovetail bar with ¼ 20 threaded holes, so it can be used on any compatible mount that accepts a Vixen dovetail, or it can be directly attached to a photo tripod. Unfortunately, this dovetail is made entirely out of plastic now, but it does the job.

Like many telescopes, the StarMax 90 optical tube has a Vixen dovetail bar with ¼ 20 holes so it can be used on any compatible mount that accepts a Vixen dovetail, or it can be directly attached to a photo tripod.

The 1.25” visual back attached to the StarMax 90 is not the same as a Schmidt-Cassegrain visual back – though adapters are available to attach such – but it has built-in T-threads to attach your DSLR and use the telescope as a long focal length telephoto lens.

Quality of Accessories

The StarMax 90mm Tabletop comes with two 1.25” interchangeable eyepieces: a 25mm Kellner (50x) and a 10mm Kellner (125x). Both use glass lenses, though the body of each eyepiece is disappointingly plastic. At f/13.9, they are more than acceptable, and the 10mm provides plenty of magnification for close-up lunar and planetary views.

The 1.25” star diagonal included with the StarMax 90mm Tabletop used to be a high-quality 90-degree prism; however, Orion has swapped this with a low-quality mirror diagonal of dubious flatness. An aftermarket diagonal will have brighter and clearer images and would be a good investment for this telescope.

For aiming, the StarMax 90mm Tabletop includes a standard battery-powered red dot finder that slides into its (also plastic) Vixen/Synta universal finder shoe attached to the side of the tube. This finder is more than adequate for aiming this small telescope at most targets.

Finally, a cheap screw-on “moon filter” (in fact, a 13% transmission neutral density filter) is thrown in with the StarMax 90. This device, designed to attach to the end of the star diagonal or one of your eyepieces, is quite silly. Not only does it dim the view far too much for this small telescope, but its low-quality glass blurs your view of our nearest neighbor. There is no harm in observing the moon’s full, unfiltered brightness through any telescope; moon filters are not a necessary accessory and are little more than a marketing tactic to get you to waste money on a few cents’ worth of tinted glass.

The Dobsonian Mount with Starmax 90

The StarMax’s tabletop mount is the same “Dobsonian” single-arm mount supplied with most inexpensive tabletop scopes, which are almost-always Newtonian reflectors. However, the shorter focal lengths of those scopes make them more suited for wide-field, low-power use, where the ability to fine-tune the scope’s position isn’t as crucial. 

In addition, a tabletop Dobsonian mount can be frustrating and tedious to use with a primarily high-power instrument like the StarMax 90. The StarMax’s compact optical design and resulting short tube make fine adjustments even more difficult, as the tube is harder to use as a lever to pivot the instrument accurately. If you have large hands, like myself, it can be hard to aim the telescope without grossly over-adjusting or obstructing most of the aperture as you attempt to maneuver the scope around the sky. This being said, the mount is at least steady once you get it on target, but it is certainly not the best that could be supplied for a 90mm Maksutov-Cassegrain design.

The StarMax’s tabletop Dobsonian mount has a ¼ 20 hole at the bottom that allows the whole telescope assembly to be attached to a photo tripod, which is nice if you don’t want to use a table. At the scope’s weight of 6.5 pounds (2.94 kilograms), however, make sure to use a relatively heavy-duty photo tripod for such a task.

Should I buy a used Orion StarMax 90mm Tabletop?

The pre-2023 StarMax 90mm Tabletop is a different telescope from the one Orion sells now. I mean, it’s basically identical to the Celestron C90 or the 90mm Maksutovs offered by Celestron, and that goes hand-in-hand with an all-metal build. The tabletop mount is the same and has the same shortcomings, but the older-gen StarMax’s included star diagonal and eyepieces are up a notch quality-wise (the provided diagonal is a prism, and a good one at that).

If you either don’t mind the limitations of the tabletop mount or plan on using a different one, there’s little that can go wrong with a used StarMax 90, pre-2023, or the newer kind. The sealed nature of the optical tube means you’re unlikely to find one with damaged optics. However, a unit with damage to either the mirror or a cracked corrector should be avoided; recoating the secondary mirror is nigh-impossible, and it is not cost-effective to recoat the primary or replace the corrector/secondary assembly.

Alternative Recommendations

The Sky-Watcher Virtuoso 90 uses a similar 90mm Maksutov-Cassegrain optical tube to the Orion StarMax 90, but with substantially less plastic. Its Virtuoso tabletop mount has full motorized tracking abilities with push-button control of fine adjustment for aiming, along with a solar filter bundled in by default. Like the StarMax 90, it works either on a tabletop or with a sturdy photo tripod attached to the bottom.

For more information on what telescope is best for you and your budget, check out our Telescope Rankings and Best Telescopes articles.

Aftermarket Accessory Recommendations

The 90-degree mirror star diagonal included with the Orion StarMax 90mm Tabletop telescope is pretty bad; we’d recommend Celestron’s 1.25” prism diagonal or a high-quality 1.25” dielectric unit to get the sharpest views possible. And while workable, the eyepieces included with the StarMax are not exactly of the highest quality. A 32mm Plossl eyepiece, for instance, provides a lower 39x and a 1.3-degree true field with the StarMax 90mm Tabletop, which is a bit more optimal for viewing deep-sky objects or initially locating your target. A 9mm “redline” or “goldline” ocular can be swapped in for the provided 10mm, yielding 139x—ideal for lunar, planetary, and double star views—along with a wider, sharper field than the 10mm Kellner design. A 6mm redline/goldline will provide 208x with the StarMax 90, which is a little bit much for the telescope’s optics to handle and will require steady skies to benefit from.

What can you see?

The Orion StarMax 90mm tabletop telescope, with its precision optics, is primarily tailored for solar system observations. It offers viewers the opportunity to witness the phases of Mercury and Venus, the intricate details on the Moon’s surface, including craters and mountain ranges, and the polar ice caps on Mars. Jupiter’s vibrant cloud belts, the prominent Great Red Spot, and its four major moons are discernible, with the added bonus of observing the moons’ transits and their shadows on the planet when these occur. Saturn’s iconic rings, including the Cassini Division bisecting them, present themselves with clarity, and observers can also identify some of Saturn’s moons. Uranus and Neptune are visible, but they will look like little more than stars and might be quite challenging to locate.

With its sharp optics, the StarMax 90mm Tabletop also offers a delightful experience for double-star observers. The telescope can split thousands of co-orbiting binary stars, revealing their colors and separating close pairs up to its theoretical Dawes limit, even under less-than-ideal sky conditions.

Unfortunately, the StarMax 90’s small aperture limits it to only the brightest deep-sky objects, and some large open star clusters and nebulae may not fit in the field of view of the telescope, even at low magnification. You’ll also likely have issues finding these objects, given the scope’s narrow field of view and feeble light grasp. However, smaller objects such as the Ring Nebula, M11, the Orion Nebula, and M35, among others, are still enjoyable to look at and reasonably easy to find. Galaxies like Andromeda might be perceivable, but they’ll appear as faint smudges, especially in areas with significant light pollution. Globular star clusters, on the other hand, will mostly appear as indistinct, hazy balls of light. For those keen on exploring the depths of the cosmos and seeking detailed views of these deep-sky objects, telescopes with larger apertures would be more suitable, such as a 4-5” tabletop Dobsonian in this price range.

Astrophotography Capabilities

The Orion StarMax 90’s direct T-thread attachment on the scope’s visual back means that you can screw it to a camera for use as a telephoto lens. Likewise, atop its provided mount or a photo tripod, it makes for a great daytime spotting scope.

Astrophotography of the Moon with a smartphone is easy to do with any telescope; we’ve written a whole guide on it for you. However, you can also use the StarMax 90mm Tabletop with a planetary camera to create stacked close-up images of Solar System objects, though you’ll want a different mount that offers motorized tracking of some sort.

Optical Design:Maksutov-Cassegrain
Mount Design:Wooden Alt-Azimuth
Focal Length:1250mm
Focal Ratio:f/13.9
Assembled weight:6.5 lbs
Warranty:1 year

Zane Landers

An amateur astronomer and telescope maker from Connecticut who has been featured on TIME magazineNational GeographicLa Vanguardia, and Clarin, The Guardian, The Arizona Daily Star, and Astronomy Technology Today and had won the Stellafane 1st and 3rd place Junior Awards in the 2018 Convention. Zane has owned over 425 telescopes, of which around 400 he has actually gotten to take out under the stars. These range from the stuff we review on TelescopicWatch to homemade or antique telescopes; the oldest he has owned or worked on so far was an Emil Busch refractor made shortly before the outbreak of World War I. Many of these are telescopes that he repaired or built.

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