The Celestron StarSense Explorer 8-inch Dobsonian ($799.95/£649.99) couldn’t come sooner. If you want the most bang for your buck when observing the night sky with a telescope, you should always consider a Dobsonian. This has been a rule of thumb in the amateur astronomy world for years, but Dobsonian telescopes are often ignored by novices because of their design, which requires them to be manually pointed at objects.
Celestron StarSense Explorer 8-inch Dobsonian: key specifications
Optical design: Newtonian reflector
Aperture: 8 inch / 203 mm
Focal length: 47.24 inches/1200mm
Aperture ratio: f/5.9
Eyepiece Focal Length: 0.98″/25mm (48x)
Total kit weight: 19.68 kg
Mount Type: Alt-Azimuth Dobsonian
They are also very large, difficult to move, and difficult to store. Why bother when you can get a small, portable, and computerized “Go To” reflecting telescope that finds objects for you?
Cue Celestron’s unique StarSense technology that finds objects using only a smartphone app. The telescope itself still needs to be pointed at objects manually, but StarSense makes that very easy, guiding you to targets in seconds.
With the arrival of the Celestron StarSense Explorer 8-inch – as well as a 10-inch version with a slightly larger aperture – are we witnessing the rebirth of the Dobsonian telescope?
Celestron StarSense Explorer 8-inch Dobsonian telescope: design
- StarSense Explorer Dock
- StarPointer viewfinder with red dot
- 2″ Crayford focuser (with 1.25″ adapter)
25mm Celestron Omni Plössl eyepiece
2″ Crayford focuser
2″ extension tube and 1.25″ adapter
StarSense smartphone dock
StarPointer red dot finder scope
Celestron Starry Night Basic Edition software
The Celestron StarSense Explorer 8 inch Dobsonian telescope is big. All Dobsonian telescopes are adequate compared to other telescope mount designs, but at least their 8″ aperture limits them to around 10kg each for the base and tube (the 10″ version weighs 13.24kg and 11.6kg for tube and base, respectively). It’s a solid tube rather than a collapsible design, so it’s not that easy to store away when not in use. That being said, this telescope has a pretty impressive design that’s packed with extras. Both the tube – which has a focal length of 1,200mm – and the base itself have built-in carrying handles to make it easy to move around. The latter also has an eyepiece holder (an excellent quality 0.98 inch/25mm (48x) Celestron Omni Plossl eyepiece is included).
At the top of the Celestron StarSense Explorer 8-inch Dobsonian telescope tube are three components; Focuser, red dot finder and smartphone holder. The Crayford focuser natively accepts 2″ eyepieces, although an extension tube and adapter are also included in the box so you can use 1.25″ eyepieces. Also in the box is a StarPointer red dot finder. Although technically you don’t really need this, it does help with alignment. It also gives you a quick way to point the telescope at the moon or if you plan to use it during the day.
Celestron StarSense Explorer 8-inch Dobsonian telescope: performance
- Limit size 14.2
- StarSense works in seconds
- Use wireless headphones for audio descriptions
Despite its fancy smartphone app, the Celestron StarSense Explorer 8-inch Dobsonian telescope is not a “Go To” telescope. In fact, it’s more of a ‘push to’, with the StarSense app acting as a dynamic guide. StarSense works really well. In our test in a light-polluted city, we were able to place an iPhone 12 Pro in the smartphone holder, reveal the small mirror positioned behind it, and align its camera with XY adjustment knobs, and then employ StarSense to take photos of the night sky. So it essentially knows where it is, along with data from your phone’s camera, gyro, accelerometer, and GPS sensors.
The app takes a bit of getting used to, but once you get the hang of how the arrows and how the app zooms in as you get closer to your target, it’s all very easy to use. Finding actual destinations couldn’t be simpler. The StarSense app not only issues “Push To” instructions, but also contains extensive lists of celestial objects that are currently visible from your precise location. This catalog has grown massively since we last looked at StarSense and now includes a wealth of deep sky objects perfect for training a Dobsonian. It’s also worth observing with wireless Bluetooth headphones, as the StarSense app includes an audio description for each larger object you point the telescope at.
When the bullseye turns green you can observe – and the views on offer are truly excellent. Bright stars have a slight four-point starburst (although Celestron’s XLT reflective coatings keep these diffraction spikes to a minimum). In our test, we easily split binaries, with fine views of the red and blue companions at Albireo in Cygnus. Ditto for the ‘double double’ near Vega in Lyra. Saturn, although close to the horizon, clearly showed its ring pattern. However, it’s in the deep sky where this scope really excels. Objects look sharp, detailed and rich in contrast. The clarity of the large globular cluster in Hercules (M13) was intriguing, as was the Andromeda Galaxy (M31). It’s easy to make reasonably fine adjustments to the field of view by moving the tube slightly (although the inverted image takes some getting used to), while the focus wheel is perfectly calibrated and works very well. Visually, this Dobsonian is an incredibly impressive product – and excellent value for money.
Celestron StarSense Explorer 8-inch Dobsonian telescope: functionality
- Practical carrying handle on tube and base
- Can attach a camera
- Requires occasional collimation
The Celestron StarSense Explorer 8 inch Dobsonian telescope is easy to use. Of course, this is partly thanks to the StarSense app, which makes alignment incredibly easy. But even without that flashy app, this is a telescope that has a decent build quality to work without fuss. The metal focus knobs work smoothly and precisely, as does the pan knob. We found the tube easy enough to maneuver while the base has smooth movements and quality bearings. It’s rigid enough, but will require a bit of adjustment if you’re spending the evening inspecting targets at the zenith. It should also be remembered that the mount is such that when looking at things near the horizon, the optics are quite close to the ground – so an open observing site is recommended. The carrying handles on both the tube and the base have proven very useful.
However, there are three small problems with using a smartphone app to point a telescope. No, no light pollution – the StarSense method seems to be able to handle that. The first issue is initial alignment, which requires the user to point this telescope at a bright star and confirm with the mirror image displayed in the StarSense app. It therefore requires deep twilight and a bright star (we used Vega). It’s not difficult, but it will trip up some absolute beginners. The second small problem is the cloud. Because the software regularly resolves the stars it sees in the smartphone mirror just before issuing the final close-in bullseye, it requires clear skies, so stargazing through gaps can cause it to lose itself. The third problem is that if you leave a smartphone in the mount, you won’t have access to your usual smartphone stargazing app or your smartphone’s camera for fast afocal lunar astrophotography. The latter is easily possible on the Celestron StarSense Explorer 8-inch Dobsonian, but you can also connect a manual DSLR or mirrorless camera to the focuser using a T-adapter.
For all their simplicity and superior light-gathering power, there is something about Dobsonians—and all Newtonian reflectors—that isn’t very beginner-friendly. This telescope needs to be collimated, which basically means that its components need to be specially aligned in order to focus the light optimally. This requires an Allen key and a Phillips screwdriver, which is a bit fiddly, but at no point during our review did we have to do this, even though the product was on the move.
Should You Buy the Celestron StarSense Explorer 8-Inch Dobsonian Telescope?
The Celestron StarSense Explorer 8 inch Dobsonian telescope is an extremely impressive telescope. While we’re sure beginners could get used to it, it’s primarily aimed at intermediate users who want a quality, inexpensive Dobsonian telescope and are comfortable with manually aiming it. As such, it’s also a great telescope for learning the night sky. However, it is not lightweight. While there are some excellent handles for carrying the tube and base separately – and it’s easy enough to pan and swivel once it’s in place – a telescope of this size requires some careful consideration. However if you have the space it comes highly recommended and should provide you with incredible deep sky views for many years to come.
If the Celestron StarSense Explorer 8 inch Dobsonian telescope is not for you
If you like the sound of StarSense but need a more compact telescope, then consider that Celestron StarSense Explorer DX102AZ, which is a must for beginners. If you want an even larger Dobsonian telescope and like to manually aim at targets, then the Sky-Watcher Flextube 300 SynScan Dobsonian is the one (opens in new tab) 12 inch opening will access the deep sky. A mini Dobsonian in the shape of the is also available for children Celestron FirstScope 76although it’s only good enough for lunar viewing.