Celestron StarSense Explorer DX 102 AZ Review (Refractor Telescope)


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If you’re a newb and not ready to commit to a motorized or large aperture telescope just yet, then make things easy on yourself by incorporating technology that your smartphone can handle.

Celestron brings the StarSense Explorer telescope to the beginner to make it easier and faster to learn the night sky with.

This model is the DX 102 AZ that is a refractor telescope with a 4” aperture on top of an alt-azimuth mount. No electronics, no motors, and no power needed.

So, what’s the smartphone for?

Let’s check out the details together.

Celestron StarSense Explorer DX 102 AZ Review

Celestron Starsense Explorer Dx102 Az

Celestron StarSense Explorer DX 102 AZ Telescope

Compare Prices at:

Amazon Optics Planet High Point Scientific

✔️ Best Feature: StarSense Explorer technology

Worst Feature: Mediocre accessories

👌 Ideal For: Stargazing, Celestial Viewing, Terrestrial Viewing, Lunar & Planetary Observation, DSO Viewing, Limited Astrophotography, Beginners

  • Optical Design: Refractor
  • Aperture: 102 mm (4”)
  • Focal Length: 660 mm (26”)
  • Focal Ratio: f/6.5
  • Eyepieces Included: 25 mm, 10 mm

My Verdict: In my opinion the Celestron StarSense Explorer DX 102 AZ telescope is a beginner’s ultimate telescope. Not only does it have great focal specs for exploring the night sky and perhaps getting in an astro image or two, it has StarSense tech that helps a learner locate and view objects that would otherwise be difficult for a beginner to find.

Who is the Celestron StarSense Explorer DX 102 AZ Best Suited to?

I think the StarSense stargazing telescope is undoubtedly designed for amateur stargazers and beginners. I feel the optics are decent, but it’s the technology that really turns it into a next-level telescope, although, it’s still entry-level. The StarSense Explorer tech allows a beginner to successfully find objects in the sky to eliminate the “I can’t find anything” syndrome that new users often suffer with.

However, I feel like it’s still a rather expensive setup for the beginner or user as a first-time buy. What are the advantages? The DX 102 has a larger aperture (4”) in a refractor optical design versus other entry-level 70 mm and 80 mm models. You also have StarSense Explorer technology that enables easy object location and even lets you know when a target can be seen through the eyepiece.

How Does the Celestron StarSense Explorer DX 102 AZ Perform?

The concept and execution of the StarSense Explorer tech has been praised by amateurs and first-time users. It makes things incredibly easy for a beginning astronomer to discover the night sky due to its intuitive tech. The refractor scope can also double as a land-based optic for terrestrial viewing with the included erect image diagonal.

However, it is a refractor and it does suffer from CA (chromatic aberration) which is known as color fringing. I feel that for amateur visual and even smartphone astrophotography, it shouldn’t be of too much concern.

As a very lightweight setup, the DX 102 is a joy to take to a different location. It’s rather compact and lightweight, and it can be used by older children that have an interest in astronomy.

Features & Benefits

StarSense Explorer Technology

This tech is actually called StarSense Sky Recognition Technology. Using LISA (Lost In Space Algorithm), the StarSense app can match targets in the sky with its database determinant on where the telescope is pointing. With LISA, the app can also alert to you to other helpful features such as when objects are too bright to view other targets or when a target is visible to be seen through the eyepiece.

The app also includes the use of plate-solving technology that incorporates use of your smartphone’s internal gyroscopes and accelerometers to essentially extrapolate data when you perform the initial setup.

The smartphone must be seated in the dock for the tech to work. Some limitations include inclement weather. Haze, cloud, and fog can affect the technology in the way that StarSense will have trouble “sensing” stars. Windy conditions pose an issue as it can shift the phone within the dock that affects performance.

Refractor Telescope

The DX 102 has a refractor optical design that uses lenses. The DX130 is a Newtonian reflector that uses mirrors. One thing to note is that refractor telescopes cost more per inch in aperture versus reflectors and catadioptric scopes. While the DX130 may be the same price as the DX 102 even though it’s larger, they’re two different optical systems.

Many prefer refractor scopes at the cost of a smaller aperture and some CA. A few benefits of a refractor include its closed tube, fixed optics that don’t require collimation like reflectors do, and with a scope of this size, it won’t magnify optical issues as much as higher power, larger apertures do.

Alt-Azimuth Mount

The mount is a simple manual alt-azimuth mount, which I like. It’s easy to use for beginners, has slow motion controls on both axes, and it comes with the bracket needed to dock the smartphone. The mount is rather small, but it holds the OTA just fine. I don’t think it’s not the best mount for heavy loads like astrophotography equipment, so a different mount would be in order if you plan on using anything other than an additional smartphone to take astro images.  

Tripod legs are made from aluminum and extend to a maximum height of 49”. It weighs 9.2 lbs, and the tube has a CG-5 dovetail bar, so it’s possible to upgrade or change out the mount/tripod in the future.

Limited Astrophotography

Okay, so it’s not a real astrophotography telescope in the way that you that think. Many may become confused with the fact that this telescope setup allows the smartphone to take photos while it’s using StarSense to direct. This is not the case. The phone is not looking through the telescope for viewing, and if it’s removed from the dock, the sensing technology ceases.

You can remove the smartphone and use an adapter to take photos, or you’ll have to use a second device. Remember, this is a manual alt-az mount, so objects wont’ stay centered in the field of view. You must manually make small adjustments to track these targets.

What about the astro images taken by StarSense?  These images are not astro images in the same sense as astrophotography. It’s for extrapolating data so that the tech can sense stars and determine their position based on where the telescope is pointed in the sky. Besides, they’re pretty ugly and I think you could take better pics yourself.

YouTube video


Mediocre Accessories

Unfortunately, the eyepieces could likely be the reason for the bad rap on the included accessories. With this package, you get Kellner 25 mm and 10 mm eyepieces providing 26x and 66x magnification. The eyepieces are plastic, and if there are any coatings, they don’t do much for viewing or imaging quality. I think the eyepieces may be your first upgrade.

The DX 102 also comes with the StarPointer red dot finder scope that you use for initial camera alignment and for terrestrial viewing. You don’t have to use it, but it’s there if you need it for when you don’t want to use StarSense technology or if your phone dies.

The included diagonal does the job, but it will reduce viewing quality in the skies and will likely need replacing after you’ve gathered some decent eyepieces.

Other Telescopes to Consider

I think the DX 102 AZ is a great telescope for stargazing however another option worth looking at is the Celestron Omni XLT 150. Find out which one is more suited to your needs and budget.

What Smartphones are Compatible with the StarSense Explorer?

There are multiple smartphone models that are compatible with StarSense. Basically, you need either an iPhone 6 or newer or an Android phone made in 2016 or newer with an operating platform of at least 7.1.2 or higher. The Android must have a built-in camera, gyroscope, and accelerometer.
Note: you can use the same unlock code up to five times for various smartphones or if you upgrade your phone. You cannot use tablets in place of a smartphone because it cannot fit in the dock.

Must the Smartphone be Realigned When Removed or Returned to the Dock?

It’s recommended that you realign the smartphone after having removed it from the dock. While you may not have to realign it every time to find objects, it’s best practice to perform realignment to ensure a well-centered object within the telescope’s field of view.

How do you Take Photos Through the StarSense Explorer?

The smartphone that uses the StarSense technology cannot be used simultaneously to take photographs as well. The phone is not connected to the telescope to take photos as it’s placed in a dock bracket that allows the sensing technology to operate. You must incorporate use of another camera device. A smartphone adapter and another smartphone would be the best way to capture astro images.
You can try a DSLR camera unguided for no longer than a few seconds unguided, but you must be weight conscious as the mount may not be able to handle the additional gear. Of course, this does not have a motor drive as it only has manual tracking.

What Size Eyepieces Work with the Celestron DX 102 AZ Telescope?

The rack-and-pinion focuser can take both 2” and 1.25” accessories. However, with a 2” diagonal and 2” eyepiece, it may creep or cause balance issues on the mount with this type of load. The diagonal and eyepieces included with the DX 102 are 1.25” accessories. To get max use out of the setup as it is, it’s best to use 1.25” eyepieces.


In my opinion the StarSense Explorer DX 102 AZ with its StarSense technology is what makes it a hit in the field.

With a 1-year manufacturer warranty, you’ll have plenty of time to figure out how to master the telescope and take advantage of defect coverages – if there are any defects.

As a first-time telescope, you’ll learn the night sky faster with StarSense than you would alone.

Celestron Starsense Explorer Dx102 Az

Celestron StarSense Explorer DX 102 AZ Telescope

Compare Prices at:

Amazon Optics Planet High Point Scientific

The allure of the cosmos captivates Fern, with its endless wonders and celestial majesty. There’s a unique tranquility, yet an undeniable thrill, in uncovering the intricacies of our vast galaxy. Away from her telescope, Fern finds solace in the pages of a gripping novel, often accompanied by a cup of her favorite tea.