130SLT Optical Performance Overview
The Celestron NexStar 130SLT computerized telescope is a standard 130mm f/5 Newtonian like the Orion SpaceProbe 130ST, Zhumell Z130, and others. It uses a plastic 2” focuser, which is theoretically capable of handling 2” eyepieces. But it’s questionable how well the focuser can handle a heavy accessory if the secondary mirror is big enough for a wide-angle eyepiece to not vignette or, of course, if the too-small SLT mount can handle another kilogram of weight being added to it.
At f/5, there is some coma, and many inexpensive eyepieces will gradually lose sharpness toward the edge of the field. Collimation accuracy is also rather important, but it’s not that difficult to get an f/5 Newtonian collimated with even the most basic collimation cap—or a bright star.
Included Eyepieces and Red Dot Finder
The 130SLT includes two 1.25” Kellner eyepieces, a 25mm for 26x magnification and a 10mm for 65x magnification. These are enough to get you started, but you’ll want additional eyepieces for more magnification options, particularly for viewing fine detail on the Moon and planets or splitting double stars.
For aligning the mount to the sky, the 130SLT includes Celestron’s standard StarPointer red dot sight, which is all you really need.
The Celestron NexStar SLT’s Alt-Az Mount
The Celestron NexStar SLT mount is a pretty simple, inexpensive alt-azimuth mount that moves up and down, left-to-right. To use it, you enter the time, date, and your location, then sight the telescope on any two or three bright stars. The mount can then map out the rest of the sky and point the telescope at any object of your choosing. This is fairly standard for most GoTo mounts. The SLT mount uses a Vixen dovetail saddle, so you can easily swap in other telescopes with Vixen dovetail bars if you wish, provided they don’t exceed the SLT mount’s capacity or crash into the base.
The SLT mount looks well-made and performs okay for the most part, but its main flaw is the skinny steel tripod legs supplied with it. They easily twist and buckle when they’re extended to a comfortable height, making the scope’s pointing less-than-accurate. Compensating for this issue is possible with some DIY workarounds, but it’s probably easier to just buy a different telescope with a more solid mounting.
The Celestron NexStar 130SLT’s poor value for the price, less-than-steady tripod, and cumbersome hand controller eliminate it from being a strong recommendation in our book. Here are some of our alternative picks, sorted by price and ranked from best to worst in value and capability.
- The Apertura AD8/Zhumell Z8/Orion SkyLine 8 offers 2.5 times as much light-collecting surface area thanks to its huge 8” primary mirror, giving you 250% brighter images – and nearly double the resolving power. The AD8/Z8 features a dual-speed 2” Crayford focuser, a simple, rock-solid, and easy-to-use Dobsonian mount, and a wide assortment of well-made accessories to get you started with.
- The Explore Scientific 10” Hybrid Dobsonian offers double the resolving power of the 130SLT and 4 times as much light gathering power in a compact and portable package – the tube is composed of 8 interlocking truss poles which disassemble in minutes leaving you with a compact arrangement when dismantled. The 10” Truss also features a single-speed 2” Crayford focuser, though the included accessories aren’t the best and the tube really needs a shroud.
- The Orion SkyQuest XT8 offers 250% more light gathering ability than the NexStar 130SLT, as with any 8” telescope, atop a rock-steady Dobsonian mount with a solid mechanical design. The included features and accessories, however, are a bit lacking out of the box compared to some of the other 8” Dobsonian options available at this price point.
- The Sky-Watcher Virtuoso GTi 150P offers slightly more aperture – and thus greater resolving power and light-gathering ability – than the NexStar 130SLT with a GoTo mount that’s operated exclusively via your smartphone or tablet with the SynScan or SkySafari Pro app. The 150P can also be aimed manually, and features a collapsible tube for maximum portability. A manual version, the Heritage 150P, is available at a lower price and is identical apart from the lack of motorized tracking or GoTo.
- The Sky-Watcher Virtuoso GTi 130P features the same optics as the 130SLT but in a collapsible tube with a dual manual/GoTo tabletop Dobsonian mount which is controlled with an app on your smartphone or tablet. The Virtuoso GTi 130P is available in a manual format, the Heritage 130P, as with the 150P from Sky-Watcher.
- The Celestron Astro-Fi 130 is essentially identical to the NexStar 130SLT, but features Celestron’s Astro-Fi onboard WiFi system allowing you to control the scope with your phone or tablet, and sturdier tripod legs that significantly improve usability and stability compared to the flimsy NexStar SLT tripod.
- The Apertura AD10/Zhumell Z10/Orion SkyLine 10 has 4 times as much light gathering and double the resolving power of the NexStar 130SLT and features a stable, easy-to-aim manual Dobsonian base. As with the AD8/Z8, this scope features a huge variety of included accessories as well as built-in features like a dual-speed 2” Crayford focuser and a cooling fan for the primary mirror.
- The Celestron StarSense Explorer 8” Dobsonian features a computerized object locator in the form of Celestron’s StarSense Explorer technology, which turns your smartphone into an easy-to-use tool to aim the telescope around the night sky without any motors or even much in the way of an initial alignment. As with any 8” Dobsonian, the StarSense Explorer 8” delivers more than 2.5x the light gathering power and close to double the resolution of the NexStar 130SLT. The StarSense Explorer 8” Dobsonian also features cutouts in the base and handles built into the tube to enhance portability.
- The Sky-Watcher 8” FlexTube Dobsonian features a collapsible tube making it easier to store and transport than a regular 10” or 8” Dobsonian, along with a pair of eyepieces and a 9×50 straight-through finder included with the telescope. However, there’s no significant weight savings compared to a standard 8” and the scope needs a shroud to keep light and dew out of the open extended tube.
Aftermarket Accessory Recommendations
Aside from its less-than-stable mount, the Celestron NexStar 130SLT’s biggest flaw may be its very short focal length of only 650mm. For high power, a 6mm “goldline” provides a measly 108x. The best planetary and lunar views with the 130SLT are arguably obtained at magnifications between 140 and 180x when atmospheric conditions permit, and for that, we’d recommend something like the Astromania 4mm Planetary, which will give you 163x with the 130SLT.
Another thing we’d recommend is a rechargeable battery/power supply for the SLT mount. If you use the scope frequently, you’ll probably burn through a lot of AA batteries quickly, and if you use it infrequently, there’s the concern of corrosion in the battery compartment to worry about. A rechargeable battery solves both of these problems and keeps you from having to run the scope from your car or a long AC cord, which is inconvenient.
What can you see with the Celestron NexStar 130SLT?
The wide field of view and large, but not huge, aperture of the Celestron NexStar 130SLT make it good for looking at large deep-sky objects like open star clusters like M11 and M45. You’ll also have no trouble viewing the Orion Nebula or the Swan, resolving a few stars in bright globular clusters, and spotting a few planetary nebulae like the Ring and Dumbbell. Most galaxies will remain little more than fuzzy blobs, though a few, such as M31 and M82, might show dust lanes. Keep in mind, however, that if maximum image brightness and detail are your goals, dark skies and aperture rule over all else. The 130SLT will struggle to show you much in the way of deep-sky views if you live in a city beyond the brightest star clusters.
The NexStar 130SLT can show a fair amount of detail on the Moon and planets, provided it’s collimated, though the 65x that the stock 10mm eyepiece can provide isn’t exactly going to be jaw-dropping. With a more powerful eyepiece (albeit not too powerful; remember, magnification isn’t everything), you’ll have no trouble spotting the cloud belts on Jupiter, the Cassini division in Saturn’s rings, and albedo features on Mars. Venus’ and Mercury’s phases, along with the moons of Jupiter and Saturn, can also be seen. And, of course, you’ll love viewing the moon. Uranus and Neptune are easy to locate with the NexStar 130SLT’s GoTo system, but will remain bluish-blurry dots at best and starlike points at worst.
Astrophotography with the NexStar 130SLT
The 130SLT’s mount does track, but it’s not accurate enough for serious deep-sky astrophotography. The short focal length of the scope itself doesn’t lend itself well to planetary imaging. A 5x Barlow and a planetary camera will let you photograph Jupiter, Saturn, Mars, and the Moon at a reasonable sampling size, but it’s a cumbersome setup, and there are better telescopes for the job if planetary astrophotography is your primary goal.