Celestron NexStar 4SE Review: Partially Recommended

The Celestron 4SE Optical Tube

The Celestron NexStar 4SE computerized telescope is a Maksutov-Cassegrain telescope with an aperture of 4” (102mm) and a focal length of 1325mm, giving it a focal ratio of f/13.

The Pointless Flip Mirror

The 4SE has an integrated “flip mirror” at the back, which means that there is a built-in star diagonal that can be retracted to allow light directly out of the back of the telescope and into a camera adapter, usually for a DSLR or mirrorless camera. But this isn’t really necessary.

This flip mirror simply adds some additional bulk and complexity to the telescope and requires an unusual threaded adapter to be utilized. A normal Maksutov gets by with the user just detaching the star diagonal. The 4SE isn’t really intended for astrophotography anyway, especially not with a DSLR or mirrorless camera, which are primarily meant for long exposures.

NexStar 4SE’s Small Field Of View and It’s Effects

A slightly larger aperture (114mm) but cheaper instrument such as the Orion StarBlast 4.5 or Zhumell Z114 can get 3.6 degrees of field of view, while the very-slightly-smaller Zhumell Z100 or Orion SkyScanner 100 can achieve a field of view of about 4 degrees across. This is, respectively, triple and nearly quadruple that of the Celestron NexStar 4SE (and they cost a fraction as much, to boot).

Of course, I realize that most of the advantages of that extra field of view are simply in finding objects manually, which the Nexstar 4SE does not need to worry about due to its fully computerized mount. However, a wide field of view is still desirable for many of the large star clusters, asterisms, and nebulae that a small telescope excels at.

If all you’re looking at is the planets, the Moon, and perhaps a few double stars, how much do you really need GoTo anyway?

Offering Just a Single Eyepiece & a Red Dot Finder

The Celestron NexStar 4SE computerized telescope comes with a single 25mm Plossl eyepiece, yielding 55x. This is good as a low-power or “finder” eyepiece for viewing deep-sky objects and initially aligning the telescope. But if you still want the best, for the widest possible field of view and lowest magnification with the 4SE, a 32mm Plossl is my favorite choice.

For optimal usage of the telescope, you’ll want something for higher magnifications. Specifically, a good high-magnification eyepiece in the 6mm to 9mm range, such as “goldlines”, the Meade 8.8mm UWA, or another eyepiece such as a Baader Hyperion or Explore Scientific 82-degree.

The only other accessory included with the 4SE is its StarPointer red-dot finder, which is used for aligning the telescope’s GoTo system.

The NexStar 4SE Mount

The NexStar SE mount is similar in all versions, but the 4SE and 5SE have a shorter fork arm on the mount and a base with 3 foot-like bits sticking out. It’s a holdover from the days of the NexStar 4GT, the 4SE’s predecessor, which was sold as a tabletop telescope.

The mount is well-made.

The tripod legs are, however, solid steel. The whole assembly is actually somewhat overkill for the Celestron NexStar 4SE’s tiny optical tube.

One thing I’d like you to keep in mind with the SE mount is that the power jack can lose connection, which will shut down the mount. The mount then requires re-booting and re-aligning. I solved this issue by installing AA batteries in the scope as a backup.

The 4SE’s tripod has an “equatorial wedge,” which theoretically allows the scope to be converted to an equatorial configuration. However, without accurate altitude adjustments or any azimuth adjustment to speak of, short of picking up or kicking the entire scope/mount/tripod combination, an equatorial mount is only needed for deep-sky astrophotography. Deep-sky astrophotography is something that the 4SE, with a focal ratio of f/13, is simply not capable of (the mount’s mediocre gearing quality doesn’t help, either).

Why The Mount Doesn’t Make Much Sense To Me

The biggest issue I have with the 4SE’s mount is that it doesn’t make much sense.

The mount weighs 17 pounds, much more than it needs to weigh. It must be perfectly leveled during setup, especially if you want the SkyAlign easy-align feature to work. It either burns through lots of AA batteries frequently or needs a good, steady source of DC or AC power. And, of course, it has to actually be aligned.

What can you see with the Celestron NexStar 4SE?

The Celestron NexStar 4SE shines primarily on the moon and planets.

• We can easily see lunar details just a few miles across, as well as the phases of Venus and Mercury.
• Mars will show its ice cap and some dark markings when it is close to Earth.
• Jupiter’s cloud belts, polar and equatorial zones, and Great Red Spot are visible, and its four largest moons, the Galilean Moons Io, Europa, Ganymede, and Callisto, appear as tiny, not-quite-stellar dots. With good atmospheric seeing, we can just see their shadows as they transit across the planet.
• Saturn’s rings, the Cassini division within them, and some faint, low-contrast cloud bands on the planet itself are no problem, and we are easily able to catch its largest moon, Titan, along with smaller moons such as Enceladus, Hea, Tethys, Dione, and Iapetus.
• Uranus and Neptune are nothing more than turquoise and deep blue dots; we would struggle to resolve the latter as more than a star at all.

Outside the solar system, the 4SE is relatively limited.

• Most galaxies, such as Andromeda, M81, and M51, appear as vague smudges of varying sizes under all but the best conditions (Andromeda and M33 will also be unable to fit into a single field of view with the 4SE). M82 is the only one that might show any detail, especially under light-polluted skies, in the form of a cigar shape and dark streaks perpendicular to it.
• Globular clusters are merely brightish fuzzy balls with maybe the slightest hint of resolution.
• A fair amount of open clusters are visible with the 4SE, but many are visually unappealing to beginners or don’t fit in the field of view.
• There are also a couple dozen nebulae visible with the scope, but overall, if you’re looking for mind-blowing views of deep-sky objects, you should probably look elsewhere. Visible does not mean spectacular.

Astrophotography with the NexStar 4SE

The Celestron NexStar 4SE GoTo telescope does well at lunar and planetary astrophotography.

I’ve attached a few images that I took with my NexStar 4SE and a cheap 640×480 webcam that I found at a flea market and attached a 1.25” nosepiece and 2x Barlow lens to.

Forget deep-sky astrophotography, however. The 4SE’s f/13 focal ratio, mediocre tracking capabilities, and the alt-az nature of the mount do not allow for good long exposure photos.

Alternative Recommendations

The Celestron NexStar 4SE is a decent enough telescope, but given its lack of performance or anything resembling good value for the money, we have quite a few alternative recommendations, regardless of whether you want a smaller and more portable computerized instrument or a larger but more capable Dobsonian telescope.

Under $700

• The Apertura AD8/Zhumell Z8/Orion SkyLine 8 offers double the resolving power, quadruple the light gathering area, and a significantly easier-to-use and more stable mount than that of the NexStar 4SE. You also get a pile of decent accessories included and features like a built-in cooling fan and 2” dual-speed Crayford focuser.
• The Sky-Watcher Virtuoso GTi 150P features GoTo just like the NexStar 4SE, but its 6” of aperture provides 50% more resolving power and about double the image brightness of the 4SE. As with the 4SE, you get a very compact instrument with GoTo, but with more performance and a lower price tag, controlled via your smartphone or tablet instead of a keypad. The 150P’s f/5 focal ratio and mere 750mm focal length produce a much wider field of view, too, and the telescope can be aimed manually with or without being powered on. The Heritage 150P, also offered by Sky-Watcher, is essentially identical to the Virtuoso GTi 150P, apart from its lack of electronics, making it a purely manual scope (but a great budget pick). The Sky-Watcher Virtuoso GTi 130P is similar to the GTi 150P but with less aperture.
• The Celestron Astro-Fi 130 boasts the same 130mm f/5 optics as the GTi 130P and is similarly operated with a smartphone, but is mounted atop a full-sized tripod, lacks a collapsible tube, and cannot be aimed manually. However, if you want a fairly compact and wide-field instrument that’s mounted atop a tripod, few better options exist in this price bracket than the Astro-Fi 130.
• The Celestron Astro-Fi 102 has the same optics as the NexStar 4SE, but without the latter’s goofy flip mirror and with a lighter and more advanced mount that can be controlled by your smartphone. A 10mm Kellner eyepiece is included along the stock 25mm, unlike the 4SE. If you like the NexStar 4SE, the Astro-Fi 102 has all the same positives but with a load of improvements.

$700-$1000

• The Apertura AD10/Zhumell Z10/Orion SkyLine 10 has 2.5x the resolution of the NexStar 4SE and more than 6.5x the light gathering area thanks to its humongous 10” primary mirror. The included accessories and features, as with the AD10/Z10, are simply excellent, the simple Dobsonian mount is a joy to use, and you get a ton of performance for the price.
• The Celestron StarSense Explorer 8” Dobsonian is similarly poorly accessorized to the NexStar 4SE—just one 25mm Plossl eyepiece and a red dot finder are included—but this scope offers some computerized capability in the form of the StarSense Explorer technology, which turns your phone into a precision pointing device, allowing you to find thousands of faint fuzzy deep-sky objects in seconds by pushing the scope around the sky. The Dobsonian base is also lightweight and the tube features carry handles to increase portability, too.
• The Sky-Watcher 8” FlexTube Dobsonian is a little more compact and thus easier to store and transport than a standard commercial 8” f/6 Dobsonian telescope thanks to its collapsible strut tube, and it includes an ample accessory kit (two 1.25” eyepieces and a straight-through 9×50 finder scope). However, the collapsible tube requires more assembly time and often more frequent collimation in the field, and it isn’t significantly lighter than a solid-tubed instrument.

Aftermarket Accessory Recommendations

A useful item is a real rechargeable battery to run the scope off of—the 4SE uses an enormous number of AA batteries and will gobble through a set after less than 24 hours of runtime. This makes a rechargeable supply a great investment that will quickly pay for itself.

I recommend the TalentCell 600Mah battery and a male-to-male power adapter. You can use Velcro, zip ties, or duct tape to secure the battery to the tripod leg.