The Telescope Optical Assembly
The “tube” of the XX12i is made up of two steel segments connected by aluminum trusses. This allows you to fit the entire scope into a smaller car than a solid-tubed, single-piece scope like the Zhumell Z12, a water heater-sized monstrosity that takes up my entire hatchback and is hard for one person to work with. The XX12i’s tube, when disassembled, turns into a 26” long lower tube assembly, eight 22” long truss poles, and an 8” long upper tube assembly.
The assembly process of the tube is pretty simple. You attach the lower part of the tube to the Dobsonian base, and then you use the hand knobs to connect the four pairs of truss poles. The upper tube assembly then sets on top of the trusses and is secured using four hand knobs. This entire process takes only a few minutes.
The main disadvantage of using a truss system is that stray light can shine into the tube far more easily, causing glare and contrast loss. This is easily solved by purchasing or making a light shroud, which is essentially a black Spandex or Lycra sock that fits around the trusses. Orion and various third parties sell them, or you can sew your own out of Lycra.
The optical quality of the XX series of scopes is outstanding; as with the XT series, I’ve rarely heard anyone complain about them. The XX12i and XT12i have both given me fantastic lunar, planetary, and deep-sky views. The primary mirror sits on a 9-point floatation cell with a cooling fan on the back.
The focuser on the XX scopes is Orion’s dual-speed 2” Crayford model. It works almost as well as a more expensive unit like a Moonlite or Feather Touch, and most users will probably never need to upgrade to one of those.
The Mount of Orion Skyquest XX12i
The XX12i’s mount is made out of particle board, as is typical with Chinese-made Dobsonians. You assemble it with a series of included screws and a hex wrench, which takes only a few minutes. And you’ll probably find yourself doing this often; the mount is tall and wide enough that it is quite difficult to fit it assembled into many vehicles without accidentally scratching the inside of your car. This is quite a big inconvenience to deal with on a regular basis, and with routine assembly/disassembly of the mount, you risk chipping it or exposing the particle board (which easily warps and rots) to moisture damage. Unfortunately, you can’t really replace the base with a plywood unit without removing the IntelliScope functionality due to the way the encoders are installed.
Unusually, unlike on their smaller XT scopes, which use a bearing of melamine or whatever covers the whole base directly on cheap Teflon pads, the XX12i and larger XX scopes use real Ebony Star on chunky, thick Teflon pads for the most buttery-smooth motions possible.
The tube secures to the mount with two hand knobs, which also adjust the tension/friction on the attitude axis. While it’s a little less convenient and less ideal compared to the spring tensioning system on the regular XT scopes, this system is much easier for the IntelliScope’s encoders to install on.
Accessories with the scope
The XX12i and XX14i both come with a 9×50 straight-through finderscope. This finder works well, but you shouldn’t need it much thanks to the IntelliScope. A red dot sight will work just as well, as will a Telrad.
The eyepieces included with the XX12i are a bit of a token effort. The 35mm DeepView (a glorified Kellner) performs rather poorly at the XX12i’s fast focal ratio of f/4.9, and actually provides too low of a magnification (42x) to be of much use; the exit pupil of 7.09mm is so big that many users will see image brightness loss and the shadow of the secondary mirror will be visible at the center of the field. The 10mm Plossl (150x) is acceptable, but you will probably want something better.
The included collimation cap with the XX12i is somewhat of a joke; you’re best off collimating on a star or using a laser collimator. Read our guide for more information on how to do that.
The Orion Intelliscope
The Orion IntelliScope system is extremely simple to use. Alignment just requires entering the time, date, and location, and aligning the scope on two reference stars. After that, the IntelliScope will pretty accurately lead you to any object you choose. The scope works fine without the IntelliScope, and you can point it at a target by hand without messing up the alignment or accuracy of the IntelliScope.
Should I buy a Used XX12i?
The XX12i is a great telescope, but given its high cost and the relatively complicated nature of its design, as well as the relatively exposed optics, care should be taken when shopping for a used one. Make sure that the Intelliscope system works, and if at all possible, try to check that the encoders are still accurate and have not been damaged. Check that the base has not been chipped and that the particle board isn’t swelling. Verify that the mirror coatings aren’t thinning or corroding, and inspect the truss poles for any damage. If you’re confident that all of the aforementioned are in good shape, then you’re good to go.
The Orion SkyQuest XX12i is a pretty massive telescope even when dismantled, as well as, of course, quite expensive and sometimes unavailable due to stock issues. Here are a few options we would recommend in lieu, though unfortunately none exactly duplicate all of its features.
- Manual Scope: The Apertura AD12/Zhumell Z12/Orion SkyLine 12 includes a dual-speed focuser and 9×50 finder like the XX12i, along with a slightly better low-power eyepiece and a collimation tool. However, a solid-tubed 12” is an absolute nightmare to deal with compared to a truss or collapsible design and you should consider your storage/transport options carefully before purchasing.
- Manual Truss Tube Scope: The Explore Scientific 12” Truss Tube Dobsonian features a significantly more compact and better designed truss tube assembly with large altitude bearings and buttery-smooth motions vastly superior to the XX12i’s mount, though it’s of course a manual-only scope. There’s no particle board to be found here, either, and the focuser is a respectable 2” dual-speed Crayford unit. However, the included accessories are lackluster at best, and the upper tube assembly needs additional baffling on top of the already-mandatory light shroud for the tube itself.
- Computerized Truss Tube Scope:The Sky-Watcher 10” FlexTube GoTo Dobsonian is fairly quick and easy to set up and remains fairly compact thanks to its collapsible FlexTube design, while also featuring fully motorized tracking and GoTo with Sky-Watcher’s FreedomFind encoders allowing you to manually aim the telescope even when it is powered on.
- Computerized Scope:The Celestron NexStar Evolution 8” is significantly less capable than a 12” scope like the XX12i, but its full motorized tracking, GoTo, built in battery and the ability to be controlled by your smartphone/tablet or the provided hand controller are huge pluses. You get some astrophotography capabilities, too, and a decent set of provided accessories to start out with.
- Partially Computerized Truss Tube Scope: The Orion SkyQuest XX14i Dobsonian is only a little bulkier than the XX12i but its 14” of aperture gives it 36% more light collecting power, while still featuring the IntelliScope encoders and object locator and a fairly easily assembled truss tube.
- Computerized Truss Tube Scope: The Sky-Watcher 12” FlexTube GoTo Dobsonian is not as compact as the XX12i but still is fairly easily transported and its FlexTube design is easier to assemble. You also of course get full motorized GoTo/tracking capabilities with the ability to manually aim if you wish.
- Computerized Truss Tube Scope: The Orion SkyQuest XX12G Dobsonian is heavier than the XX12i but otherwise similar in bulk and performance, with full GoTo and tracking capabilities but still able to be aimed manually thanks to its dual encoder design.
Aftermarket Accessory Recommendations
We’d definitely recommend adding some better accessories to the XX12i. It’s severely limited by its included eyepieces. But before you think about any of those, you need to purchase the XX12 light shroud. It’ll greatly reduce the amount of stray light that can get into your telescope and hamper contrast or cause glare issues. Along with that, the shroud prevents dew, dust, dirt, and critters from getting on your optics while you use the telescope. Even if you don’t live in a light-polluted or damp environment, the shroud cuts down on even the faintest background sky glow from starlight and atmospheric scattering, and insulates the cold metal truss tubes for a more comfortable user experience.
As for eyepieces: for low magnification, an 82-degree eyepiece in the 20mm to 30mm range would be our pick, and probably the first thing you should upgrade. Our favorites are the Explore Scientific 82-degree and Meade UWA range, but you could splurge on something like a 22mm Tele-Vue Nagler if you feel so inclined.
Next would be a medium-power eyepiece in the 16mm to 12mm range. Another ES82, UWA, or Nagler will do it, but if you’re on more of a budget a Baader Hyperion or 16mm Explore Scientific 68-degree will work nicely.
Lastly, you’ll need a high-magnification eyepiece in the 6mm to 10mm range (or preferably two separate eyepieces at either end of that). Any of the eyepieces from the aforementioned lines will work but our favorite would probably be the 6.5mm and 9mm Baader Morpheus.
A UHC filter significantly boosts contrast on nebulae with the XX12i under light-polluted skies. It’ll actually help quite a bit with contrast under dark skies too. A 2” filter can thread onto the included 2” to 1.25” adapter for use with 1.25” eyepieces.
Normally we’d recommend supplementing the included 9×50 finder with something like a Telrad or Rigel Quikfinder, but as you’re only going to need the finder at all to align the Intelliscope system when you set up the telescope, you probably would be better off spending your money on other items.
What can you see?
The Moon shows details as small as a mile across, and is dazzlingly bright through the XX12i. Some users might want to use a moon filter to cut down on the brightness, though at moderate to high magnifications, your eyes should adapt pretty quickly.
Mars sports a few dark albedo features (in reality, dark patches of sand/dust on its surface) as well as the ice cap when it’s around opposition. With some techniques to reduce Mars’ glare, you can spot Phobos and Deimos when they’re at maximum elongation from the planet.
Jupiter’s two main cloud belts are extremely obvious through the XX12i, and you can also spot its polar zones and other features, including the Great Red Spot (Jupiter’s weather is always changing). Its 4 largest moons, the Galilean moons, are clearly not stars, and cast tiny shadows as they transit the planet. On very steady nights you can tell that they have slightly different sizes and colors.
Saturn and its rings are fantastic with the XX12i. You can easily see the Cassini Division, and with steady seeing and good collimation, the Encke Division can just be glimpsed. At least 5 or 6 of Saturn’s moons are also easily visible.
Uranus and Neptune are little more than turquoise and azure dots through the Z12, but their moons are visible. Uranus’ moons Ariel, Umbriel, Titania, and Oberon are about as dim as Pluto and require a careful eye to be spotted, while Neptune’s lone large moon Triton is quite easy to spot.
Pluto can be spotted with the XX12i under decent skies, but don’t expect to see anything more than a faint star-like point. The Intelliscope will get you close to Pluto on its own, but you’ll need to carefully look at charts or sketch the area over a few nights to figure out which dim “star” is really Pluto.
For optimal viewing of deep-sky objects, you’ll really want to bring your XX12i to dark skies. If you can, expect to see something like the following:
Galaxies – Many of the brighter galaxies show a lot of detail through the XX12i. You’ll have a lot of fun browsing the many Messier and NGC galaxies that feature spiral arms and dust lanes, as well as spotting the H-II regions in M33, M51, and M101 under dark skies. The Virgo Cluster contains dozens of galaxies that are easy to spot, and with some luck, you might be able to glimpse the faint members of the Perseus A and Coma galaxy clusters.
Globular star clusters – The XX12i resolves even the relatively faint globular clusters like M53, and you might get hints of color and detail in brighter globulars like M15, M4, and M13.
Open star clusters – Even with lots of light pollution, open clusters are fantastic to look at with the XX12i. Even faint stars in clusters like M35, the Pleiades, the Double Cluster, and M6 will show color and pop out against the background like jewels on black velvet.
Emission nebulae – The few bright emission nebulae that dot our skies (namely Orion, the Lagoon, and the Swan) are quite a sight to behold through the XX12i, featuring blue-green colors and detail that often exceeds what’s visible in photographs. A UHC filter will improve them even further, at the expense of any natural color and many of the fainter stars in the field of view.
Planetary nebulae – Most of the easier-to-spot planetary nebulae are quite detailed and vibrant in the XX12i, and the Intellscope makes it extremely easy to locate the smaller ones, which may not pop out while scanning for them at low magnification.