Home Comparisons Celestron NexStar 127 SLT vs. Celestron NexStar 5SE – The better option for advancing beginners

Celestron NexStar 127 SLT vs. Celestron NexStar 5SE – The better option for advancing beginners

by Rizka Amir
Celestron NexStar 5SE

Finding a telescope is hard work. However, finding a telescope designed to grow with you and your interests is even harder. Celestron NexStar 127 SLT vs. Celestron NexStar 5SE will look critically at two capable telescopes, popular for beginners and intermediate users alike.

The first telescope purchase for me was daunting for two reasons. First I was an absolute novice to astronomy and telescopes in general. Second and most daunting of all, was because I wasn’t sure if my choice then would be useful after I had advanced my new interest. That was 8 years ago: and after running both the local college and community astronomy club, I have advanced my knowledge, use and purchasing skills of telescopes. Most beginners are faced with the decision to find the best telescope. However what should be an even bigger question is whether said choice will benefit you as you advance you. Celestron NexStar 127 SLT and the Celestron NexStar 5SE are two of the most popular beginner or amateur level telescopes. However, how do they hold up against advancing users? Here is a review and comparison of Celestron NexStar 127 SLT vs. Celestron NexStar 5SE, where I will go into finer details about each telescopes, comparing both of them to help you find the best option for you as you continue to grow in astronomy.

What are the differences between the Celestron NexStar 127 SLT and the Celestron NexStar 5SE?

Type of telescope
Maksutov-Cassegrain optical system
Hybrid telescope with Schmidt-Cassegrain Optic system
Aperture 127mm or 5 inches, 1500mm Focal length, f/12 Focal ratio and 300X, 18X as highest and lowest useful magnification.
Aperture 5 inches, 1250mm Focal length, f/10 Focal ratio and 241X, 15X as highest and lowest useful magnification.
Computerized AltAzimuth Mount with single fork arm
Fully Automated GoTo mount
60X, 167X

Celestron NexStar 127 SLT vs Celestron NexStar 5SE- How these telescopes compare

Working principles

Among the most fundamental differences between the 127 SLT and 5SE is in their working principle. This is because different telescope types have different working principles. In this case, both these instruments are hybrid/compound/catadioptric style devices and rely on BOTH mirrors and lenses to function. Cassegrain telescopes use a corrector lens in combination with the rest of the rest of its optics. Maksutov Cassegrains have thick curved spherical corrector. Schmidt Cassegrains use a THIN corrector which is aspheric in nature. Both these Cassegrains design often lead to a compact design with an optically corrected system.


Numbers such as the aperture, focal length and focal ratio on either option varies greatly. The 5SE and 127 SLT have various similarities and differences optics wise. For example, they are both 5 inch aperture telescopes, but with different focal length and thus a different focal ratio. The Celestron 127 SLT has the following specifications: aperture 127mm or 5 inches, 1500mm Focal length, f/12 Focal ratio and 300X, 18X as highest and lowest useful magnification. Alternatively the Celestron NexStar 5SE SLT has a 125mm aperture, with a 1250mm Focal length, and f/10 Focal ratio. These differences will influence optical capabilities in terms of what celestial objects you can see and how clearly you can see them.

Speaking of optics, optical coatings are a big deal when it comes to influencing optics. The Celestron NexStar 4SE uses Celestron’s own StarBright XLT coating. However, Celestron does not specify the type of coating on the 127 SLT. Luckily, they do state that the optics on this particular model include a full coating.

Celestron NexStar 127 SLT vs Celestron NexStar 5SE- A comparison review

Celestron NexStar 127 SLT Overview and Key features

NexStar 127SLT Computerized TelescopeThis Star Locating Telescope is a computerized device that is a reliable and quite accurate. Celestron manufactures the SLT with quality optics in a Newtonian optical system. Coupled with high performance features, many users rely on the 127 SLT as a favorite option during sky gazing sessions. Here are some of the key features that make the 127 SLT so capable.

This instrument being a Maksutov- Cassegrain style telescope has the following optics specifications ; a focal length of 150mm with a 127mm aperture and f/12 focal ratio. This style of telescope is catadioptric/ compound and relies on a series of mirrors AND lenses within its optical system. While the 127SLT is more of a planetary and lunar scope, it still performs quite well and is very portable However, it has some limitations in regards to use in deep space viewing and imagery.

Among these helpful features include access the Starry Night Astronomy software that contains over 36k celestial objects. If you chose to, you can print out these 3D renderings of stars, printable maps and images of galaxies and exoplanets. Beginners can utilize this database when they don’t know where or even what to start with. Advanced users in addition to learning about new objects, can utilize this database to improve their expertise in astronomy or even heighten their telescoping experience. Focusing this telescope simply involves turning a knob located on the sides to adjust the positioning of the primary mirror.

The Celestron 127 SLT is equipped with an automated Alt-Az mount. In combination with other features, tracking and location of objects across the sky is quite simple. . This mount is placed on a pre assembled steel tripod that is adjustable: a feature many beginners not used to setting up will appreciate. Additional features such as the Sky Align feature and compatibility to the Star Sense technology by Celestron ensure you have easy alignments or even automated alignment depending on the feature you use.

Because the 127 SLT runs on 8 AA batteries it can perform for long hours without worry. Alternatively, Celestron advices to use the power tank option that is an external battery sold separately. Using a 12AC adapter, you can directly connect the 127SLT to an external power-source for use. Usually the 8 batteries are contained in an internal compartment that is designed to help eliminate cord ward issues that often come about from external battery pack.

With this purchase, you will receive several accessories, including 2 eyepieces, the 20mm and 9mm. Additional accessories such as the finderscope assist with centering an object for quicker and easier observation.

What we like

  • Made with quality optics
  • Compact design
  • No tool, easy assemble instrument
  • Lightweight and portable telescope
  • Generates great moon images
  • Allows access to large database for tracking, locating and even learning purposes

What we don’t like

  • Somewhat pricey for that aperture size
  • Comes with plastic viewfinder

What you can see with the NexStar 127 SLT

  • Detailed lunar surface features and its phases
  • Mars’ polar caps
  • Saturn’s rings
  • Can be used outside visual astronomy for daytime use or wildlife viewing
  • Jupiter and its moons


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Celestron NexStar 5SE

NexStar 5SE Computerized TelescopeThe NexStar 5SE is a well equipped telescope that is easy to use and even easier to upgrade. This flexibility to suit both beginners and advanced users is one of the major things we like about this instrument. Additionally, it includes quality optics at a great price. Here are some of the features that make this orange tube classic a good choice of telescope.

Optics on the 5SE are arranged in a Schmidt Cassegrain optical system and include the following specifications: an aperture of 125mm, 1259mm focal length and f/10 focal ratio. This SCT instrument has its optic surfaces covered with the patented XLT star Bright optical coating that helps significantly improve the light gathering power on this telescope.

Unfortunately, this system generates obstruction caused by the secondary mirror inside the tube. Said obstruction results in issues where resolution and contrast on this scope become slightly impaired, compared to other optical systems. To be more specific: the secondary mirror obstruction by area on the 5SE is at 16.6% while by diameter is at 40%. Other optical elements including the magnification ranges from 18X as the lowest useful magnification and 295X as the highest theoretically useful magnification. An aluminum optical tube houses this system’s optics.

The device is mounted on Celestron’s Alt-Az mount with its revolutionary single fork arm feature. Thanks to these additions, setting up, tracking and location become quite simple tasks with the 5SE. In fact, this telescope breaks down into smaller lightweight pieces that are easy to transport and set up. This is the sort of convenience anyone who likes to move their telescope around will appreciate. Apart from the sturdy construction and high quality material, the accompanying GoTo feature provides accurate tracking and pinpointing of many celestial objects. Access to their 40K+ celestial object database ensures you will not run of things to observe.

This telescope is powered by 8 AA batteries and reinforced by steel sturdily design tripod, you can expect to use this telescope for long sessions without fail. Weighing in at a total 17.6 lbs, the 5SE is quite easy to lug around, even to camping sites, the back yard, you name it.

For any beginners worried about the alignment part of using a telescope, Celestron equips this model with the Sky Align feature. This feature will require that you center you have 3 bright objects your scopes eyepiece bright objects then press ALIGN. Alternatively, Celestron recommends that you can attach the Star Sense Auto align which will automatically align itself.

Advancing users will enjoy the compatibility on the 5SE which will ensure they can utilize it for various activities. For example, once you provide the required GPS coordinates, you may use Sky Sync or completely automate alignment with the Star Sense Auto Align technology.

In case you develop interest in astroimaging and astrophotography, you can utilize the 5SE for lunar and planetary imaging. Additionally, the SLR port on the telescope allows use with the SLR cameras for imaging purposes. By replacing the secondary mirror on this telescope with a camera, DSLR or CCD camera, this telescope can take wide field images. Additionally, the in-built in wedge lets the user take long exposures.

Accessory wise, you will receive a finderscope, a 25mm eyepiece among other accessories. You can keep any delicate or small pieces which are likely to get lost in the accessory tray provided.

What we like

  • Easy to use
  • Compact and portable
  • Comes with the XLT StarBright coating for a 56% increase in light gathering capacity
  • Uses the dual axis motors on its mount to allow exact tracking and reduced instances of vibration
  • Great for beginner and advanced user
  • Compatible with a variety of high tech accessories
  • Great for astrophotography
  • Free access to Starry Night Astronomy Software

What we don’t like

  • Battery life could be better

What can you see with the Celestron NexStar 5SE?

  • Saturn’s rings
  • Jupiter’s cloud bands
  • Lunar phases and some geographic feature
  • Several deep space objects including Hercules Globular cluster’s stars, The Whirlpool galaxy’s spiral arms and much more


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Verdict: so which is better? Celestron NexStar 127 SLT or Celestron NexStar 5SE?

As you progress from complete beginner and learn various ways you can enjoy a telescope, the 5SE would best suit your new tastes compared to the 127 SLT. In fact, the 5SE makes several adjustments and comes with compatibility to outside devices and features that allow this device to grow with you.

Frequently asked questions

How can I use the Celestron NexStar 5SE?

The 5SE is a versatile telescope from the NexStar SE series. With it, you can access various celestial bodies, directly during observations or indirectly by accessing the 40k + celestial object database. During observation, a properly set up 5SE will generate great planetary, lunar and even deep space images

What is a MAK style telescope?

Maksutov Cassegrain telescopes in full are Cassegrain style telescopes. These are catadioptric telescopes which combine the Cassegrains reflector path with its own corrector lens. While the Celestron NexStar 127 SLT is a MAK style device, the 5SE is a SCT, or as commonly known: Schmidt Cassegrain Telescope.

What is the difference between the 127 SLT and the 5SE?

Apart from the optics, the difference in optical system design and general exterior design, the 127 SLT and 5SE are from two different series, both by Celestron. While they may share some classic Celestron features like the popular Sky Align Tech, they are two very different instruments.


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