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. It’s a good scope on a mount that would be good for almost anything besides what is actually sold with it. There are good reasons it is the only catadioptric telescope out there sold on a tabletop mount without slow-motion controls or motors.
This being said, the StarMax 90 is not a bad telescope, but it would’ve been nice if the designers had put a little more thought into it.
The Optical Tube
The StarMax 90 OTA is the same as Celestron’s C90 optical tube, a 90mm f/13.9 Maksutov-Cassegrain – the only difference being it’s attractive ruby-red powder coated finish, and a red-dot finder instead of the cheap straight-through finderscope supplied with the C90.
The StarMax 90 has 3 Allen head collimation screws which can be used to collimate the scope if need be, though Maksutov-Cassegrains rarely if ever, fall out of collimation. I’ve actually dropped a 90mm Mak a few feet onto the ground by accident and the collimation remained fine. This is certainly a testament to the build quality of these fine telescopes.
The views of the Moon and planets through the StarMax 90 are exceptional – though, the mount causes some issues with achieving that, as we’ll go over later in this review. Jupiter’s Great Red Spot, though currently at nearly its smallest ever, can be seen, as can the Cassini Division in Saturn’s rings, around 30 craterlets in the Moon’s Clavius crater, and other interesting sights. Double stars are also fun to look at with this telescope. However, the StarMax 90’s slow focal ratio of f/13.9 combined with its 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 at low power.
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 – it has built-in T-threads to attach your DSLR and use the telescope as a long focal length telephoto lens.
The StarMax 90 comes with two eyepieces: A 25mm Kellner (50x) and a 10mm Kellner (125x). At f/13.9 they are more than acceptable and the 10mm provides plenty of magnification for planetary views. The StarMax also comes with a red-dot finder on an interchangeable Vixen/Synta-type dovetail shoe and a quality 1.25” prism star diagonal.
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 motion and position isn’t as crucial.
In addition, a tabletop Dobsonian mount, lacking in slow-motion controls or a large enough physical size to make fine adjustments easy, 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 makes fine adjustments even more difficult as the tube is harder to use as a lever to pivot the instrument.
This being said, the mount is not terrible, 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.
I really want to like the StarMax, and if it were priced a little lower, I’d probably be more forgiving of its shortcomings with regards to its mounting choice. However, for the same price as the StarMax, you can buy a larger tabletop Dobsonian which will be much less frustrating to track with and have arguably better views, and if you really want a 90mm Maksutov you can get one with motorized tracking or even GoTo for just a little more money.
This being said, it’s not a bad choice and if you happen to have some other good reason to buy one I certainly wouldn’t pass it up. The StarMax is still a nice telescope, just maybe not the best available at its price point.