Celestron StarSense Explorer DX 102AZ Review: Incredible Tech, Cheap Build

written by TTB
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Although the build quality feels cheap, StarSense technology is groundbreaking.


Celestron has always been the company that takes the risk of innovation in astro-tech. With StarSense Explorer DX, they took the risk again, and it seems to have paid off. 

The technology built into the StarSense Explorer App is impressive.

The age of smartphone and telescope symbiosis was already here; now it is real.

If you are going for as much optical as possible, you should take a look at Dobsonians. But if technology and ease of use is your vibe, than StarSense Explorer DX 102AZ is worth exploring.



102mm Aperture

660mm Optical Tube

Moderate Chromatic Aberration

Let’s start off with the optics. How good are they? Well, for the price, they are nothing but below-average. You are paying for the technology more than the optics with this telescope.

The optics are much worse than what you can get for the price.

Celestron StarSense Explorer DX 102AZ is an f/6.5 refractor. If you don’t know what that means, this design is pretty standard among beginner telescopes. It provides average performance with both deep space and Solar System objects.

Planetary Performance

What can you see with Celestron StarSense Explorer DX 102AZ? You are limited to major and popular Solar System objects.

Jupiter shows its stripes and Galilean Moon’s. You can get a glimpse of The Great Red Spot.

Saturn shows its rings and its largest moon Titan.

Mars will appear as a bright red disk. It may show some surface detail as black and white stains on ideal conditions and with a high-quality, high-powered eyepiece such as a Goldline.

Venus appears as a bright yellow disk, and its phases are observable.

Neptune and Uranus will appear tiny blue dots if they appear at all. They are challenging to observe with any telescope.

Mercury will appear as a tiny dot. 

The Lunar observations are delightful. The amount of craters and mountain ranges you can observe is impressive, but keep in mind. There will be some color inaccuracy, which is called Chromatic Aberration.

Chromatic Aberration Example – Not Taken with StarSense Explorer DX 102AZ. The Moon will look much larger and detailed with this telescope.

Chromatic Aberration

The main problem with the planetary performance is Chromatic Aberration. Although some expensive eyepieces and filters reduce this defect, you can’t get rid of it completely. Here is an example image, which is not taken with StarSense Explorer DX 102AZ

Some don’t mind this problem, and for some, it is a deal-breaker. I recommend going for the DX 130 model if color accuracy is vital. It has slightly better optics.

Expect some chromatic aberration.

Deep Space Performance

Deep space performance is better than Planetary for two reasons: Chromatic Aberration is less effective, and the 2″ focuser combined with a 2″ eyepiece provides delightfully wide-field views. 

The 2″ focuser improves deep space observations dramatically.

The 102mm is a limiting factor, especially if you are living near light-polluted areas. You are limited to significantly bright deep space objects such as Pleiades, Hercules, Orion, and Andromeda. Celestron, most likely on purpose, has a limited amount of objects in their StarSense Explorer App database. The optical power is simply not high enough.

Is Astrophotography possible with Celestron StarSense Explorer DX 102AZ?

No, astrophotography is not possible. You can get amateur images of Solar System objects by attaching a DSLR camera to the telescope or with your smartphone camera, but that is it. 

For astrophotography, you need to counter Earth’s rotation so that the telescope “stays still”. For that, you need to spend thousands of dollars on motorized equatorial mounts. Astrophotography is an expensive hobby at the moment.




Slow-Mo Knobs

The mount has a stiff build because it is made of cheaphard plastic. This is not bad for stability and reliability, but it is not smooth enough to move the optical tube. The mount barely holds.

The mount is mostly plastic.

There are also slow-motion knobs for each axis. This is a smart design choice since you will be fine-tuning all the time while looking at the app. 

The mount is as “budget” as it gets. If butter-smooth motion and rock-solid stability is necessary for you, StarSense Explorer DX 102AZ is not a model to go for. Dobsonians and TableTops are better choices for that.




Celestron doesn’t provide tripod width, but I believe it is a near-2″ model. 

The legs are aluminum instead of steel, but that is fine with such a lightweight telescope. The tripod is OK in terms of stability. Vibration Suppression Pads improve stability dramatically and are cheap upgrades.

The Smartphone Slot

Celestron took the time to create a well-built slot for smartphones. The clutches on the sides are adjustable for size, and the base is a nice-feeling smooth fiber instead of plastic. I think this is to prevent your smartphone from getting scratches and is appreciated.

The smartphone slot is one of the bests I’ve seen on a telescope.



Real-Time Simulation

Great Accuracy

Works Without WiFi

Let’s talk about the elephant in the room, StarSense Explorer App.

I had my doubts about the app in the beginning. Astro-tech is known for being buggy, cumbersome, and, overall, useless.

StarSense Explorer App is marvelous and will change the astro-tech industry from the ground up.

But not this time. This thing works marvelously.

Before getting into the details, I have to mention that clear skies are an absolute necessity for this thing to work, so keep that in mind if you live near a large city like New York or Los Angeles.


Setting up is brilliantly easy. Celestron sends a code with every StarSense Explorer DX Telescope. You just enter the code to the app, and you are good to go.


Alignment is also easy, but not as effortless as the set up procedure. You have to choose a particularly bright object to use for alignment. Using the Moon at the beginning might be a smart decision. 

You point the red cross to the object and find the object in the eyepiece as well(The eyepiece has to be 25mm or more.). When you hit done, the app knows your location, and it knows exactly where the optical tube is pointing at. Brilliant.

Plate-Solving Technology

How does the app know all this stuff? The technology is called “Plate-Solving”, and it uses software and image recognition to identify the telescope’s location on the night-sky. It renews the process every time you change where you are observing or move the optical tube to a different object. The process takes 1-2 seconds, depending on the clearness of the night-sky, longer. 

Push the scope in the arrow’s direction and, voila, the object is in view.

The app uses plate-solving, the gyroscope, the accelerometers, and the compass inside the smartphone to keep the simulation accurate. It is mind-blowingly precise. And, the user keeps interacting with the telescope by pushing the scope in the direction of the arrow. 

At times the app has trouble recognizing the optical tube’s location due to the clearness of the sky and light pollution. But still, this is a groundbreaking innovation. With software updates, the tech will get better, and for almost no cost at all, you get a real-time simulation of the night sky and the telescope.

StarSense Explorer App is ingenious.



Kellner Eyepieces

Red Dot Finder

Plastic 1.25″ Diagonal

2″ Focuser

The accessories are, except the 2″ focuser, just thrash. I’m sorry to be blunt, but that happens to be the case.

The eyepieces are Keller models, which is as cheap as it gets. They are merely functional and should be replaced with Plössl eyepieces as soon as possible. This is not an expensive upgrade and will improve the image quality quite a bit.

The finder is a red dot model. It is also cheap and plastic, but since this a telescope that finds objects with an App, this is acceptable.

The 1.25″ diagonal is outrageously bad. It is completely plastic and can’t take advantage of the 2″ Focuser. 

The accessories are all useless. It is clear that Celestron sends these so that you can spend some extra money on accessories. I expected at least one Plössl eyepiece, but no.


As I’ve mentioned many times in this review, the focuser is 2″ instead of 1.25″, which opens the realm of incredible, 2″, wide-field eyepieces. 

But, the build quality is not pleasing. The material inside is not completely metal, and the motion is sticky. Greasing the focuser is a good solution, but most beginners won’t want to deal with that.

The focuser is mostly plastic, but a delightfully wide 2″ model.

You will have some balancing problems with a 2″ diagonal and a 2″ eyepiece. You can attach additional weights to the optical tube’s front to prevent this from happening, but again, this is not ideal. 

Although it is not well-built, the 2″ focuser is appreciated. Upgrading a focuser is a pain, and no beginner should deal with that. With wide-field eyepieces, the value of the optical tube increases dramatically.


Plastic Mount

Sticky Focuser

Cheap Accessories

Moderate Power

Although the technology is impressive, there are quite a few problems with this telescope.

The build quality is pretty bad. The mount is mostly plastic, and the focuser feels sticky.

The accessories that come with the telescope are cheap and made of plastic. The 1.25″ diagonal is especially useless.

There are 3x or 4x more powerful at this price range. Dobsonians are still vastly better in terms of optical power and reliable build quality.


I don’t mind the plastic and the low powered optics. Innovative technology is rare in astro-tech, and great-working innovative technology is even rarer. 

StarSense Explorer DX 102AZ is a smart and fun way to start out with astronomy. But, if you live near a large city, the app may not work well, so I recommend a manual model or a GoTo in such a case.

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