The 6SE’s optical tube is an orange version of the Celestron C6, which is a 6” f/10 Schmidt-Cassegrain. The C6 is the newest of Celestron’s standard SCT models. It came out in 2006. The C5, C8, and C14 were made in 1970, and the C11 and C9.25 were made in 1977 and 1993, respectively. The C6 offers significantly more light gathering ability and resolution than the C5, and is a favorite among experienced astronomers as a “grab n’ go” telescope.
Thanks to its small size, the C6 doesn’t really suffer from the mirror flop problems that plague larger Schmidt-Cassegrains nor have a particularly narrow field of view. That being said, despite being physically compatible with a 2” diagonal, the C6 cannot actually illuminate the field of view of a 2” low-power eyepiece and will vignette quite badly with an f/6.3 reducer. Thus, the scope isn’t going to provide a field of view much larger than 1 degree (about 2 full moons)-which means it isn’t ideal for wide-field vistas of star clusters and nebulae, though a 1-degree field is still plenty big to satisfy most users.
The C6 also has HyperStar compatibility. This means that with Starizona’s Hyperstar corrector, you can remove the secondary mirror, stick the Hyperstar in its place at the front of the telescope, and image with a CCD or CMOS camera at a focal ratio of f/2. However, the C6 only works with relatively small sensors in its Hyperstar configuration, both due to the physical constraints of the design and the fact that a large camera housing can start to obstruct most of the telescope’s aperture. Additionally, a HyperStar costs more than the entire telescope and is more useful if the C6 is mounted on a German equatorial mount rather than an alt-azimuth like the NexStar SE.
Being a Schmidt-Cassegrain, the C6 does need to be collimated from time to time. Contrary to what some folks might tell you, this is not a particularly scary or difficult process and absolutely does not require sending it back to Celestron! You simply adjust 3 small screws on the secondary mirror housing while pointed at a bright star – it’s arguably easier than collimating a Newtonian. Check out our collimation guide for more information. However, don’t buy the oft-advertised “Bob’s Knobs” or thumbscrew collimation knobs for the 6SE-they’re overpriced and counterintuitively cause the telescope to go out of collimation more often due to the insufficient torque they exert to keep the secondary secured tightly.
The Eyepiece and Red Dot Finger with 6SE
The 6SE comes with a single eyepiece – a 25mm E-Lux Plossl providing 60x. It’s a good starter eyepiece for low magnification, but as with any telescope, you’ll want at least a few extra eyepieces to provide a range of magnification options. We’ll get back to this topic in the “Aftermarket Accessories” section.
Like most GoTo telescopes, the 6SE also comes with a simple red dot sight to complete the initial alignment before it can automatically slew itself around the sky.
Nexstar 6SE Mount Capabilities
The 6SE and 8SE both use a larger version of the NexStar SE mount with a tall, single-arm fork and a rather robust steel tripod with 1.75” legs. Unlike the smaller mounts sold with the 4SE and 5SE, the 6/8SE mount does not come with a built-in wedge. The loss of this feature is not especially relevant, as it is little more than a useless gimmick on those telescopes.
The NexStar SE mount uses the same NexStar+ hand controller supplied with most of Celestron’s computerized telescopes. It looks pretty much like a pocket calculator. To use it, you enter your location, time, and date, point the telescope at two or three reference stars, and off you go. The whole process takes about 10 minutes from start to finish. Once the telescope is aligned, you can choose from lists of deep-sky objects, the planets, and double stars to point it at, which it’ll slew to automatically with high accuracy, assuming you’ve aligned it properly. However, getting the initial alignment to work can be challenging for some beginners, and the NexStar controller makes no indication of where in the sky your targets are or what is visible. Additionally, most of the objects available in its catalogs are too faint for the C6 to reveal, and its “40,000 objects” claim is mostly due to the fact that it features tens of thousands of SAO-designated stars. You’re basically limited to the solar system, the Messier catalog, and many of the brighter NGC objects.
Should I buy a Used NexStar 6SE?
If the price is right, go for it. Make sure that the telescope powers on and slews correctly, and that the interior of the telescope is clean.
The 6SE is just about the pinnacle of computerized (and indeed, non-Dob) telescopes under $1000, so if you’re looking for an alternative, the only thing we’d recommend in its place would probably be a Dobsonian. Here are some of the best options:
- The Apertura AD10/Zhumell Z10/Orion SkyLine 10 offers 2.8 times as much light collecting power and just under double the resolution of the NexStar 6SE, mounted atop a simple and easy-to-aim Dobsonian mount that sets up in seconds and with a variety of high-quality features and accessories like a built-in 2” dual-speed Crayford focuser and cooling fan along with a 9×50 right-angle finder, laser collimator, and 2” wide-angle eyepiece. It’s got nearly unprecedented value for the money and the views will knock your socks off.
- The Apertura AD8/Zhumell Z8/Orion SkyLine 8 is a similarly great bargain to the larger AD10/Z10, though if you can afford the larger of the two models you’ll be rewarded greatly as the overall weight and bulk difference between a 10” and 8” is nearly immaterial.
- The Explore Scientific 10” Hybrid Dobsonian offers a lot of aperture for the money in a compact and easily collapsed package with high-quality fittings. However, besides the telescope itself you basically get nothing – the provided 2” focuser is a simple single-speed Crayford unit, the included red dot finder and eyepiece are almost unusable and the telescope needs a shroud to keep light out of the optical tube – along with a new finder and at least a couple of new eyepieces to go with it. When dismantled, the 10” Hybrid takes up hardly any more space than the 6SE and its tripod, and it is easy to put together and be observing faster than it takes to get the 6SE’s tripod leveled and the mount done with a 2-star GoTo alignment.
- The Sky-Watcher Virtuoso GTi 150P features full motorized tracking and GoTo like the 6SE, and its tabletop Dobsonian mount and collapsible optical tube take up about as much space as the 6SE optical tube and mount head – thus opening up the possibility of a carry case or backpack and airline travel. You do need a steady surface to set it on, but if you can accommodate that need you’ll be rewarded with a wider field of view than the 6SE can achieve with the ability to aim the telescope entirely manually as well as control its mount via your smartphone/tablet instead of an old-fashioned hand set controller. The Virtuoso GTi 150P is also available in an all-manual configuration as the Heritage 150P from Sky-Watcher.
- The Sky-Watcher Virtuoso GTi 130P is similar to the GTi 150P except slightly scaled down; like the 8” vs 10” normal Dobsonians we’d recommend the 150P over the 130P due to the minimal difference in size, weight, and cost compared to the jump in capabilities that the extra inch of aperture of the 150P gives you. Like the 150P, you can also get this telescope in a manual-only format for a lower price as the Sky-Watcher Heritage 130P.
- The Celestron Astro Fi 130 has less aperture than the 6SE, but its vastly shorter focal length and the ability to take 2” eyepieces allows you to achieve a much wider field of view which is more ideal for viewing deep-sky objects. The Astro Fi mount is also controlled via your smartphone or tablet rather than a hand controller. The optics are the same as those in the Virtuoso GTi/Heritage 130P tabletop Dobsonian.
- The Apertura AD12/Zhumell Z12/Orion SkyLine 12 has double the aperture – thus double the resolution and quadruple the light gathering ability – of the NexStar 6SE, though its massive Dobsonian base and gigantic optical tube stand in stark contrast to the petite and ultra-portable design of the NexStar 6SE and its mount/tripod. This telescope is a monster for sure, but more than worth it – and arguably easier to use – if you have the space for it.
- The Celestron StarSense Explorer 10” Dobsonian offers the performance of any good 10” Dobsonian with the added bonus of Celestron’s StarSense Explorer technology to aim the telescope (though not for you – it just gives a readout and instructions on the display of your smartphone) and with handles on the optical tube and cutouts in its base to make transport a little less difficult. Like the 6SE, only a single 25mm Plossl eyepiece and red dot finder are provided, and the 2” Crayford focuser is only a single-speed unit. The 8” StarSense Explorer Dobsonian is also a good choice, though a 10” is equally portable and provides better views and thus we’d recommend the larger scope provided you can afford purchasing it.
- The Explore Scientific 10” Truss Tube Dobsonian has all the great performance of any 10” Dobsonian, vastly besting the NexStar 6SE yet collapsing into only a slightly larger volume when dismantled. This telescope is extremely compact compared to a solid-tubed 8” or 10” yet still comes together in minutes, and features an all-aluminum frame with no cheap plastic or particle board parts. The focuser is also a fancy 2” dual-speed Crayford design. However, the included finder and eyepiece are abysmal and you’ll need to buy or make a shroud for the open tube.
Aftermarket Accessory Recommendations
The NexStar 6SE really could use a few extra eyepieces. For starters, we’d recommend the beloved 6mm “goldline” for 250x, a fairly high but still reasonable magnification for the Moon, planets, and double stars. For moderate magnification, a 15mm goldline or 15mm Agena Starguider, either of which will provide 100x, is a good choice. Various other eyepieces at focal lengths in between these would also be good, but we’d recommend just two to start, along with, of course, the included 25mm Plossl.
The 6SE also benefits significantly from a dew shield. In addition to delaying the formation of dew or frost on your front corrector lens, the dew shield helps block stray light from entering the telescope tube and reducing contrast.
The last accessory we’d like to recommend is the Celestron SkyPortal Wi-Fi Module. It replaces the antiquated included hand controller by connecting the telescope to your smartphone or tablet, allowing you to align and control the 6SE with Celestron’s free SkyPortal app or the vastly superior SkySafari app.
What can you see with the Celestron NexStar 6SE?
Within the solar system, the Celestron Nexstar 6SE can do a lot. Expect to see the following:
- Mercury & Venus: Phases
- The Moon has a ridiculous amount of detail, with features as small as a mile visible. We could go and write paragraphs about how great the views of the Moon are with the 6SE, or arguably any decent telescope, but we couldn’t possibly do it justice, so we’ll let the views speak for themselves.
- Mars: The ice caps are fairly obvious even when Mars is far from Earth. Around opposition, you can see a bunch of dark shaded areas, which are just duller colored sand.
- Jupiter: The cloud bands and Great Red Spot look great. With good sight, you can pick out mottled details and ripples within the cloud bands and the brownish polar zones. Jupiter’s 4 large moons are especially obvious as disks when they eclipse and transit the planet.
- Saturn’s rings are easily visible, as is the Cassini Division within them, the latter provided you have good sight. Around half a dozen moons can be spotted, along with faint variations in the tones of Saturn’s cloud bands. Saturn’s largest moon, Titan, is visibly not a star and appears a slightly gold color.
- Uranus – A small turquoise dot. The moons are out of reach of anything under 10 inches in aperture.
- Neptune – A near-stellar blue dot. Its largest moon Triton can just barely be glimpsed under dark and steady skies.
Outside the Solar System, the NexStar 6SE is a solid performer, albeit limited somewhat by its aperture and field of view. You can expect to see a lot of open star clusters like M35, M11, and M67. Some large clusters, like the Pleiades (M45) and Beehive (M44), cannot fit into the field of view with the 6SE, though they can still be enjoyed. The bright globular star clusters such as M13, M15, and M22 are kind of resolved with 6 inches of aperture-though barely, and only with fairly decent skies. Smaller globulars will remain fuzzy patches of light.
The few bright emission nebulae that dot our skies look magnificent in the 6SE, particularly if you use a good UHC nebula filter on them. The Trapezium star cluster’s fainter members, nestled within the heart of the Orion Nebula, are an easy catch. Planetary nebulae look decent with the 6SE, and some begin to show teal or blue coloration.
The 6SE’s aperture is enough to start showing you a fair number of galaxies, but you won’t see detail unless you are under truly dark skies. With dark skies, however, galaxies start to come alive – M51’s spiral arms can be vaguely glimpsed, as can the dust lanes in M82, M64, and M31. M33, M63, and M101 may also reveal faint spiral arms.
The Celestron NexStar 6SE is also a fantastic double star splitting scope, especially thanks to its lack of diffraction spikes from spider vanes that a Newtonian reflector typically suffers from. Sub-arcsecond doubles are possible with good seeing conditions.