As the world of astronomy and astrophotography has evolved in recent years, so have telescopes. Celestron has been at the forefront of this revolution with their range of NexStar telescopes, including the SLT, SE, and Evolution series, along with other computerized scopes under the Astro Fi and LCM lines. Each telescope offers unique features and capabilities that make them suitable for different types of astronomers and astrophotographers. In this article, we take a closer look at these three models to compare their performance and determine which is best suited for your needs. We will examine the optics, portability, imaging capability, ease-of-use, and more to help you make an informed decision on which model is right for you.
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A Brief Overview of Celestron NexStar Telescopes
All of Celestron’s NexStar and other beginner computerized telescopes are GoTo telescopes, which use computer-driven motors to find and track objects in the night sky. This requires an alignment procedure of pointing the scope at a couple of bright stars so it has something for reference. After alignment is complete, the telescope will automatically point at whatever you want, with operation controlled either with a provided hand controller or via an app on your smartphone or tablet.
All of the Celestron telescopes reviewed here are alt-azimuth mounted, which means that they move up-down and left-to-right. This makes them poor choices for deep-sky
astrophotography. The NexStar Evolution and CPC telescopes are sufficiently high-quality that they can be converted to equatorial mount configurations with a wedge, but are still less-than-ideal for deep-sky astrophotography compared to a true German equatorial mount. However, for imaging the Moon and planets, an alt-azimuth mount is fine for the job.
The biggest problem with any GoTo telescope is, of course, that your money is going to the mount in a greater proportion than it is to the telescope; in cheaper instruments this translates to more of you money going into the computer/software aspect than the mechanical design of the mount itself. As such, cheaper computerized telescopes tend to be small – often as little as half the aperture of a comparably priced manual instrument, depending on the exact specs. The time-consuming setup and alignment process of a GoTo telescope can also obviate any convenience in an otherwise lightweight or portable design, and as such we wouldn’t recommend a GoTo scope below around 5” (127mm) aperture. They are of arguably limited utility at apertures of under 8-10” (203-254mm); the upper bound of this is usually where the biggest beginner scopes lie. You should definitely consider the pros and cons of a computerized scope before purchasing one in lieu of a manual unit, especially if you are choosing your first telescope or a gift for someone else.
We would rate the Celestron computerized telescope lines each as a whole as follows:
- LCM – 2.5 / 5 stars
- SLT – 3.5 / 5 stars
- Astro Fi – 4 / 5 stars
- NexStar SE – 4.2 / 5 stars
- NexStar Evolution – 4.5 / 5 stars
- CPC – 4.5 / 5 stars
Celestron LCM Telescopes
The Celestron LCM telescopes are a “budget” line designed to go after newbies and often from non-astronomy-oriented vendors as an impulse buy. These telescopes feature extremely poor quality optics, mechanics, and computerized pointing abilities, and as such, we do not recommend any of them. The Celestron LCM telescopes are a complete rip-off and do not provide the quality performance typical of a good scope at their price range, which can in fact be obtained. The LCM mount’s poor quality motors, software, mechanical design, and cheap plastic parts, combined with the tiny or severely flawed optics of every scope offered with this mount configuration, makes it next to impossible to recommend to anyone.
The LCM mount is sold with several telescopes. The most prominent of these is the 114LCM, a 114mm “Newtonian” which is actually a Bird-Jones, using shoddy optics and a cheap corrector lens inserted into the focuser in a meager attempt to compensate for its flaws. This telescope provides dim, fuzzy views and is not on par with a true 114mm Newtonian reflector which can be found for the same or an even lesser price. There is also a tiny 76mm Newtonian reflector sold with the LCM mount, which is limited in light-gathering power and resolution to the point of being of little use on anything but Solar System objects. The other telescopes are small achromatic refractors, which are wobbly and undermounted on the LCM mount and do not provide ample light-gathering power for views of much outside the brightest deep-sky objects, the Moon, and the planets, obviating any utility of a GoTo system. As such, some of the cheaper Celestron computerized telescopes are poor choices simply on account of their meager apertures, and we would always recommend you consider all of the pros/cons of a computerized versus manual instrument, particularly if you’re shopping for your first telescope. A mount which can find anything for you is of little purpose if the telescope riding it is incapable of showing more than a handful of easily located objects, as is the case with the LCM line.
The LCM telescopes are ranked by us as follows:
- 90LCM – 3 / 5 stars
- 80LCM – 2.9 / 5 stars
- 76LCM – 2.8 / 5 stars
- 70LCM – 2.7 / 5 stars
- 60LCM – 2.1 / 5 stars
- 114LCM – 2 / 5 stars
Celestron NexStar SLT Telescopes
The NexStar SLT (Star Locating Telescope) telescopes are some of the cheapest computerized scopes offered by Celestron, alongside the LCM series (not recommended) and the Astro Fi telescopes which are essentially an upgraded version of the SLT. The NexStar SLT mounts use parts and electronics based on the decades-old NexStar GT line and come paired with a variety of telescope optical tubes. In the US, the options usually consist of a 90mm Maksutov-Cassegrain, 102mm f/6.5 achromatic refractor, 127mm Maksutov-Cassegrain and 130mm f/5 Newtonian reflector. For those outside the US, the NexStar SLT mount is also sold paired with a 5” Schmidt-Cassegrain and 6” Schmidt-Cassegrain optical tube.
The NexStar SLT mount is very cheaply made and uses tiny steel tripod legs, making it less-than-stable and prone to tracking errors. The GoTo system of these mounts as well as the tracking work well enough for casual observation, but the cheap gearing can be frustrating for planetary imaging and any deep-sky astrophotography is out of the question due to the alt-azimuth nature of the NexStar SLT mount. The mount is not particularly steady even with the tripod legs retracted all the way, and as such with larger telescopes it is frustrating to use and unlikely to be able to locate and center objects over long observing sessions accurately.
We only really recommend the NexStar 127SLT and 6 SLT, and even then, not highly. The 127SLT features a stopped-down 120mm of aperture but the mount is reasonably steady with it. The C6 XLT optical tube paired with the NexStar SLT mount is a bit under-mounted, but the optics of the telescope are excellent and provide great performance. The 5 SLT is fine but provides worse performance than the 127SLT and is usually at a higher price. The occasionally-available 114SLT is a decent scope, with a super-wide field of view enabled by its short 450mm focal length and resting rock-solid on the SLT mount, though you really don’t need a computerized mount for such a wide-field scope.
The NexStar 130SLT is rather wobbly and provides poor value for the money compared to the superior Astro Fi 130 version, while the 90SLT is too small for the GoTo system to be anything but ineffectual. The NexStar 102SLT has poor views and a poor mechanical design thanks to its too-short dew shield and low-quality focuser.
You may also occasionally see a NexStar 80SLT or 60SLT. These are small, long focal-length refractors which are of little use in viewing anything but the Moon and planets, neither of which require GoTo or tracking, and are kind of wobbly on the SLT mount as well as pointless and overpriced.
The NexStar SLT telescopes are ranked by us as follows:
- 127SLT – 3.7 / 5 stars
- 6SLT – 3.6 / 5 stars
- 114SLT – 3.6 / 5 stars
- 5SLT – 3.5 / 5 stars
- 130SLT – 3.5 / 5 stars
- 90SLT – 3.3 / 5 stars
- 102SLT – 3 / 5 stars
- 80SLT – 2.9 / 5 stars
- 60SLT – 2.5 / 5 stars
Celestron Astro Fi Telescopes
The Celestron Astro Fi telescopes and mounts are essentially an updated, improved version of the Astro Fi. Gone are the rickety steel tripod legs and the ancient hand controller; the Astro Fi uses thicker aluminum legs and replaces the hand controller with a WiFi network, allowing control of the telescope with an app such as SkySafari or Celestron’s own free SkyPortal app. The app interface is a lot easier to use – albeit slightly less reliable – than a hand controller, while also cutting the cost of these telescopes somewhat. The internal parts of the mount are also somewhat improved, with quieter and more accurate tracking than the SLT. These telescopes feel like modern precision instruments, despite their plastic parts and relatively small apertures. There are certainly better deals for the money, but for a computerized scope you can’t beat the value of the Astro Fi lineup, or at least the Astro Fi 130 kit.
As with the NexStar SLT line, the Astro Fi mount is available with both 6” and 5” Schmidt-Cassegrain optical tubes outside the US, but these combinations are rarely available in the United States. While not the steadiest mount out there for the C6 XLT, the Astro Fi 6 is certainly a good buy if you’re in the market for one, and the 5” model is also acceptable if a bit sub-par optically. The Astro Fi 130 – undermounted in its SLT configuration – is a decent pick, too, especially for the price – though the Sky-Watcher Virtuoso GTI 130P and 150P duplicate its capabilities and add the ability to be aimed manually at a lower price, with the latter offering greater aperture. The 102mm Maksutov-Cassegrain model is decent – if a bit small to be advantageous to be equipped with GoTo – while the 90mm refractor model is rather wobbly and provides fairly unimpressive views, particularly for the high price it commands.
The Celestron Astro Fi telescopes are ranked by us as follows:
- Astro Fi 130 – 4.1 / 5 stars
- Astro Fi 6 – 4 / 5 stars
- Astro Fi 5 – 3.9 / 5 stars
- Astro Fi 102 – 3.7 / 5 stars
- Astro Fi 90 – 3.4 / 5 stars
Celestron NexStar SE Telescopes
The Celestron NexStar SE (“Special Edition,” though they’ve been around for over 15 years now) telescopes are reminiscent of Celestron’s original Schmidt-Cassegrain telescopes from the 1970s in appearance, thanks to the use of their popular C8 and C5 optical tubes and orange paint jobs. The 5, 6, and 8SE scopes are Schmidt-Cassegrains while the 4SE is a Maksutov-Cassegrain. All feature metal gears and can nominally be converted to equatorial use with a wedge; the 5SE and 4SE use a mount/tripod with a built-in wedge. However, the 4/5SE’s built-in wedge has no fine adjustments making it useless, and the tracking of the mount is simply not good enough to enable long-exposure astrophotography while the C5 XLT and 4SE optical tubes would be poor choices for the job in any case.
The NexStar 6SE is easily the best telescope of the NexStar SE lineup. The C6 XLT optical tube offers decent views with ample aperture for deep-sky observation without being too bulky, and the SE mount supports it well. The 8SE is undermounted and wobbly; you can see even just from looking at it that the scope is top-heavy and its slender single-armed mount cannot hold the tube steady. As such, it is not the best; the 5SE is similarly less-than-ideal due to the high price and relatively mediocre performance of the C5 optical tube, as well as the negligible difference in volume compared to the far more capable 6SE.
The NexStar 4SE, while nicely made, is extremely bulky and expensive for such a little and relatively incapable telescope, the built-in “flip mirror” decreases the overall image quality of the otherwise-flawless Maksutov-Cassegrain optics, and of course, the built-in wedge is a gimmick; the Celestron Astro Fi 102 has the same optics but is a lot more compact, affordable, and easy to use as well as lacking the annoying flip mirror of the 4SE.
The Celestron NexStar SE telescopes are ranked by us as follows:
- 6SE – 4.2 / 5 stars
- 8SE – 3.8 / 5 stars
- 5SE – 3.8 / 5 stars
- 4SE – 3.6 / 5 stars
Celestron NexStar Evolution Telescopes
The Celestron NexStar Evolution telescopes resemble the NexStar SE in basic outline but differ greatly in overall design and performance. The NexStar Evolution telescopes add superior motor and gear design, a built-in lithium rechargeable battery, a beefier tripod, built-in handles, and the ability to control the telescope either with the hand controller or over the scope’s own WiFi network – you also get two eyepieces provided by default instead of the single low-power ocular offered with the NexStar SE scopes, though this is of little concern at such a high price point.
The NexStar Evolution line is offered in 9.25”, 8” and 6” configurations, along with a 5” model which is seldom seen and not really worth the money. In addition, Celestron offers a “deluxe” 8” Evolution with EdgeHD optics and StarSense AutoAlign technology. The EdgeHD optics are of little advantage on a telescope primarily meant for visual observation; the only advantage is in the HEPA-filtered vents, which accelerate the telescope’s cooldown to ambient temperatures on cold nights, while the StarSense AutoAlign is often glitchy and saves a couple of minutes of effort at best.
The NexStar Evolution 8 and 6 are both great choices from this lineup, offering excellent portability, user-friendliness and a high level of build and optical quality – though the in-use advantages of the Evolution 6 over the cheaper NexStar 6SE are minimal and views at the eyepiece will be identical as they use the same telescope tube and optics. The Evolution 9.25 uses a much bulkier tripod than the smaller Evolution models but the single-arm design is similarly problematic as with the NexStar 8SE for such a big tube, and as such we’d recommend the CPC 9.25” or an equatorially-mounted configuration of the Celestron C9.25 XLT optical tube instead.
The Celestron NexStar Evolution telescopes are ranked by us as follows:
- Evolution 8 EdgeHD StarSense – 4.3 / 5 stars
- Evolution 8 – 4.3 / 5 stars
- Evolution 6 – 4.2 / 5 stars
- Evolution 9.25 – 3.9 / 5 stars
- Evolution 5 – 3.9 / 5 stars
Celestron CPC GPS Telescopes
The Celestron CPC GPS telescopes are the biggest, bulkiest, and arguably most well-made of the Celestron alt-azimuth computerized telescopes. They consist of fork-mounted 8”, 9.25”, and 11” Schmidt-Cassegrain telescopes in both regular XLT and EdgeHD configurations. These scopes don’t use WiFi connections by default, but an adapter can be purchased and they do feature automatic time, date, and location updating built-in thanks to their GPS receivers in the mount. The CPC telescopes can be used for deep-sky astrophotography when converted to an equatorial configuration with a wedge, but they are not as versatile or capable as a German equatorial mount, which also offers the ability to interchange different telescope optical tubes if you wish. The mounts are rock-solid and have extremely accurate pointing and tracking for visual use.
The biggest disadvantage of the Celestron CPC telescopes is their weight and bulk. The tubes cannot be removed from their mounts, and as such they can be annoying to pick up or carry; the width of the fork arms also makes them take up a lot of space when stored. As a result we probably wouldn’t recommend the 8” model, while the 11” model can be too much for some people to pick up (the tube/forks together weigh over 60 lbs) and you may have to opt for a configuration which places the C11 XLT or EdgeHD optical tube on a German equatorial mount which can be dismantled into lighter and less awkward components. The EdgeHD optics don’t provide much of an advantage for visual use with the CPC telescopes, but of course greatly improve deep-sky imaging usefulness; the cooling vents and mirror locks can be of some aid as well, and the latter is particularly beneficial for planetary astrophotography with these telescopes.
The Celestron CPC GPS telescopes are ranked by us as follows:
- CPC 1100 EdgeHD – 4.4 stars
- CPC 1100 – 4.3 stars
- CPC 925 EdgeHD – 4.2 stars
- CPC 925 – 4.1 stars
- CPC 800 EdgeHD – 4 stars
- CPC 800 – 3.9 stars
