Celestron’s NexStar 8SE promises to be the latest and greatest rendition of their legendary C8 telescope line, and is the lowest-priced model of their currently available Schmidt-Cassegrains. But is it really all that it’s cracked up to be?
The Optical Tube
The NexStar 8SE optical tube is an 8ʺ f/10 Schmidt-Cassegrain, otherwise known as the C8 telescope. Celestron has been producing C8s in basically the same style since 1970, when the orange tube C8 made its debut. Celestron did produce a blue and white C8 as early as 1965, but these scopes were only available at f/12 and f/17 focal ratios and are very rare and expensive.
Although the C8 scopes have undergone revisions when it comes to the design of the tube, as well as new coatings and adding Hyperstar compatibility, the C8 is more or less the same scope that it was forty years ago.
The 8SE scopes are pretty good optically, though collimation can be tedious as with any Schmidt-Cassegrains. You can read how to collimate an SCT in our guide.
Speaking of the lens cap, it’s nice, made of plastic, and it twists and locks into place. This has been a feature of all Celestron SCTs since the 1980s.
The NexStar 8SE has a long Vixen dovetail bar on the side of the optical tube, but it is largely decorative in purpose as the scope will only balance when slid basically all the way forward.
Interestingly, the focus knob of the 8SE is on the bottom side of the tube when used on the stock mount. I guess this is because it would cost Celestron a fair amount of money to rotate the dovetail 90° for one scope model, so they decided to have it made on the same production line as their equatorially-mounted scopes. These also have their dovetails on the bottom of the tube and the eyepiece 90° on the right side.
The 8SE’s moving-mirror focuser does cause some image shift (wobbling of the primary mirror on the rod causing the field of view to jiggle when focusing), but nothing too severe.
The back of the 8SE optical tube has the industry-standard Schmidt-Cassegrain threads, which allow you to attach a variety of accessories such as a 2ʺ star diagonal, focal reducer, DSLR T-adapter, and various other items.
The NexStar 8SE comes with a single 25mm Plossl eyepiece, a quality 1.25ʺ prism star diagonal, and a 1.25ʺ visual back.
While the 25 mm Plossl eyepiece works well for low power, you will probably want a 2ʺ diagonal and a few wide-angle 2ʺ eyepieces for low powers, and also a few various 1.25ʺ eyepieces for higher magnifications. You can attach a 2ʺ diagonal simply by unthreading the 1.25ʺ visual back and threading a 2ʺ diagonal for SCTs on in place, or by purchasing a 2ʺ visual back and a 2ʺ diagonal with a 2ʺ nosepiece. The latter is less convenient but there are more refractor diagonals to choose from.
The NexStar 8SE’s finderscope is a simple red-dot sight, which is all you need to align the GoTo system. After alignment is complete, you don’t really need a finder at all.
The NexStar 8SE’s mount is the same as the one supplied with the NexStar 6SE. While it does work pretty well with the C8 optical tube assembly, it is not ideal to support the telescope, and can be jiggly at high magnifications. This is particularly a problem if you are using any heavy accessories or have the legs extended. This also presents the possible problem of knocking the scope out of alignment if you’re not careful.
The 8SE mount takes eight AA batteries, but I recommend only using these as a backup. Get a portable 12-volt DC power-supply and cord. Celestron even sells some under their PowerTank line.
However, you should always keep AA batteries in the scope’s battery compartment, because if external power is lost accidentally and there is no internal backup, the scope will have to be rebooted and realigned.
The 8SE’s hand controller contains a catalog of about 40,000 objects for the telescope to point at. While the 8ʺ aperture can show an impressive amount of deep-sky objects and double stars, most of the 40,000 objects in the NexStar database are simply uninteresting and unaccompanied stars.
The 8SE mount has a Vixen saddle and thus it can, in theory, take other optical tubes, but nothing besides a similarly sized or smaller Schmidt-Cassegrain or Maksutov-Cassegrain will be able to clear the base.
What All Can You See?
Once initial setup, alignment, and collimation are out of the way, the 8ʺ aperture of the 8SE will show you a lot.
In the solar system, you can explore:
- Mercury and Venus’ phases
- The moon’s ridges, faults, valleys, mountains, flatlands, craters, and more – any feature bigger than a mile is visible provided good atmospheric conditions and collimation
- Mars’ albedo shading, its ice cap, and dust storms
- Jupiter’s bands, cloud belts, the Great Red Spot, and its moons as tiny colored disks
- Saturn’s rings and the division in them, its cloud belts, and a half dozen of its moons
- Uranus as a small turquoise disk, with possibly one or two of its moons
- Neptune and its moon, Triton
Outside the solar system, you can complete the entire Messier catalog given half-decent skies, and even the Herschel 400 catalog with effort. Thousands of galaxies and star clusters, as well as hundreds of nebulae, are yours to explore, and are all readily accessible with the 8SE’s GoTo system.
How Good Is the 8SE For Astrophotography?
The NexStar 8SE is capable of very good lunar and planetary astrophotography with either a CCD camera or a DSLR. Both need a 2x or 3x Barlow lens for optimal sampling and the latter requires a T-adapter. Just take a couple minutes of video and process it with free programs like Registax or AutoStakkert.
Simple deep-sky astrophotography of objects like the Orion Nebula and the Andromeda Galaxy is possible with the NexStar 8SE, provided you obtain Celestron’s f/6.3 reducer and keep exposure times to under twenty or thirty seconds. Any longer than that and the alt-azimuth mount’s field rotation and small inaccuracies of the tracking will blur your images.