Celestron NexStar 102SLT Refractor Telescope Review

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The NexStar line of telescopes by Celestron was a sort of experiment. Or at least that is how it appears on the surface. The line includes Schmidt-Cassegrain, Maksutov-Cassegrain, reflector and now a refractor telescope among its ranks. Usually, a line of telescopes sticks to a theme. The theme of the NexStar line is computerized functionality. It is a theme they have pursued with largely good but occasionally mixed results.

The NexStar 102SLT is a 102mm objective lens refractor telescope that includes all of the NexStar technology with it. It is a decent size and solid design that gets more right than it gets wrong.


  • Refractor design
  • 102mm objective lens
  • f/6.47 focal ratio
  • 241x highest theoretical magnification
  • 14lbs assembled weight

It is interesting to see a computerized refractor telescope as they are usually only manual controlled. The Celestron NexStar 102SLT Refractor Telescope is a good mashup of refractor versatility, NexStar technology, and image quality all packaged at a decent price.

Celestron NexStar 102SLT Refractor Telescope Review
  • A computerized refractor telescope is neat
  • Accessory potential
  • Light and durable design
  • Manual control is shaky
  • Slow to fully set up for computerized use
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The Celestron NexStar 102SLT Refractor Telescope is on the smaller side of the NexStar lineup but largely avoids the pitfalls that doomed the 90SLT design.

Classic Refractor Optics

This telescope manages to keep its head just above the water in terms of optics I would say meet muster for usability with the NexStar technology package. With a 102mm (~4”) diameter objective lens and a focal length of 660mm (26”) you get a solid sized refractor telescope. Being above that 4” mark for primary aperture is an important characteristic to have when talking about serious stargazing.

The ability to gather light from distant stars is the single most important part of a telescope’s design. 102mm for the primary opening is a size that offers a good amount of light potential which opens this telescope up to being able to see some good sights.

The short body lowers the focal ratio of this scope down to f/6.5 which is a little low for a refractor. Refractors usually have higher focal ratios but a low focal ratio is not bad if you have the aperture to support it. This telescope does.

So what this means for viewing…

This combination offers an opportunity for some great views. The image quality on this scope is very good minus the usual aberrations that occur with refractors. This is one area where this scope is also unique.

The low focal ratio means that this scope is better at wide-angle viewing, things like nebula and galaxies which will give less chromatic aberration than the usual high focal ratio targets that refractors are generally best at.

You will still be able to get the classic views of the solar system but unlike a lot of other refractors, this scope has the specs in order to peer deeper into space. It will be able to show you some of the Messier objects which are usually reserved for reflectors. Viewing objects like these also reduce your potential for distracting visual imperfections that can arise with refractor telescopes.

Vastly Portable

Refractor telescopes are generally more portable than their design counterparts due to the sturdier design of lenses versus mirrors but this telescope is especially portable. It has a strong body and durable design that can stand up to some travel.

The optical tube length of 26” is rather short which makes it easy to put in the backseat of almost any vehicle. It won’t be bulky to store or take with you. It also weighs very little coming in at a light 14lbs.

This makes the Celestron NexStar 102SLT Refractor Telescope an ideal candidate for an adventure telescope. It can be physically set up and broken down very quickly. It doesn’t have a ton of complicated pieces or parts and it can be put up almost anywhere.

Easy Setup out the box
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If you want to try your hand at stargazing over the darkened ocean shore or from the top of a hill you hiked to for the night, this would be a great companion. Not only is it a durable refractor scope but it comes with the Celestron database and SkyAlign tech so you can explore unfamiliar skies.

Not everyone has a great vantage point for stargazing, but this telescope is fully capable of going to those dark sky locations and then showing you the items worth seeing automatically. This is bolstered by the Sky Tour feature of the included database of celestial objects.

Sky Tour, if used properly, will generate you a list of objects worth seeing depending on your location. This can be a fun and unique way to look at the sky from various locations as you take your telescope on the road.

In short, this telescope would be great for anyone who likes to explore dark and unfamiliar skies. It is greatly portable and has a unique use for the NexStar computerized features.

A 21st Century Refractor

The refractor telescope was the very first telescope designed way back in the 17th century. Since then, it has been a steady and stable part of the telescope arsenal. It is a tried and true design that has stuck around this long for good reason. Celestron has taken that classic design and upgraded it for the modern age.

Refractors rarely get the computerized treatment so it is refreshing to see that here. The Celestron NexStar 102SLT Refractor has all of the advanced technology that Celestron adds to all of its NexStar telescopes. This includes the 40,000 object database stored in a handy controller, SkyAlign tech and the automatic goto mount that utilizes both to work independently of your input.

Normally, for a backyard telescope, I would say you best look elsewhere for a better, more powerful and robust telescope to utilize the database that ships with this model. However, with how portable and versatile it is, I think this scope redeems itself by being able to be a unique travel scope.

The Celestron NexStar 102SLT Refractor would reach its fullest potential by being kept in a car by outdoorsy people who love to hike and travel the wilderness. This telescope, if fed with a proper amount of batteries, can really unlock new and interesting skies from wherever you want to take it.

Other refractors are often used for this purpose, as travel telescopes. However, none of them have this suite of technology built in to really help them out. You’ll never aimlessly putter around a sky at a national park again once you have Sky Tour to help you out.

Accessories? No. Potential? Yes.

True to form, even on their refractor, Celestron continues to deprive all of their NexStar models of any good accessories. This kit comes with two eyepieces. One at 25mm and one that is 9mm for a low zoom and high zoom mode. They also threw in a basic red dot finderscope. And that is it.

The bad news is that is very, very skimpy for a refractor telescope’s accessory list. The good news is, this refractor is kitted out to be compatible with 1.25” accessories which means the nearly unlimited selection of refractor accessories is available to you.

I would be very interested to see someone kit out their refractor with some of the excellent accessories on the market including filters, Barlow lenses, and diagonals and then see them put to use with the Celestron technology. That could be super fun. It would be easier than ever to try out different filters and then be able to actually look at something different with them applied because of the database.

Even getting an eyepiece kit and trying out the vast array of refractor eyepieces on different things from the database could keep someone busy for a very long time.

Bottom line is, the included accessories are lacking but there is potential to fill out the accessories yourself. If you want to spend just a little bit more money you could really make a unique computerized telescope.

The Weakest Leg

The only big complaint about this telescope is that it is not super stable during manual use. Clearly, this scope was designed with the goto mount in mind and using it manually is not as smooth or stable as some other telescopes. This is mostly fine, you will adjust to the wobbling and finicky nature of the manual controls if you are going to be using that way often.

The other complaint some people raised was that aligning it with SkyAlign and having it find the objects for you is slow. This is compared to using a fully manual refractor on an altazimuth mount, which is how most people are used to using them. I didn’t find it to be that slow. It takes a good fifteen minutes to get it running the way you want to use for a good session. I suppose that is fifteen minutes slower than a fully manual version but it is not that bad.


For a smaller telescope, this refractor really pulls its weight. The unique combination of a portable refractor and the NexStar tech pack really makes for an interesting telescope. I would suggest the Celestron NexStar 102SLT Refractor to anyone who wants to try out a computerized refractor and especially anyone who likes to travel with their telescope.