Rank Category: 150 mm Dobsonians (Both Tabletops and Full-Sized)
A 6′′ tabletop Dobsonian is great for those who need an ultra-portable scope with a decent aperture, but it will really need a custom support or a permanent solid surface, not just a table. In contrast, a full-sized 6′′ Dobsonian doesn’t need any custom support or table and is still surprisingly lighter and more portable than you might think. However, the tabletops still offer greater portability and may offer more features or better value for money in the 150 mm aperture size. The field of view with a 6″ f/5 tabletop equipped with a 1.25″ focuser is comparable to that of a 6″ f/8 full-sized Dobsonian with a larger 2″ focuser. It’s because the faster f/5 focal ratio in tabletops can compensate for the smaller 1.25″ focuser. Freestanding Dobsonians, with their slower f/8 focal ratio, are vastly easier to collimate than their tabletop f/5 cousins. That said, if budget allows, we still recommend upgrading to an 8″ or 10″ Dobsonian.
The Sky-Watcher Virtuoso GTi 150P is a fully computerised 150mm tabletop dobsonian telescope in a compact, lightweight package. It features quality optics, well-made included eyepieces, and the ability to be used manually even while the mount’s electronics are powered on and aligned with the sky. At its price, it’s hard to argue against this excellent instrument—remarkably, it costs about the same as a manual-only 150 mm telescope. After the StellaLyra 8″ freestanding Dobsonian, among our beginner readers, it ranks as the second most popular choice.
The Bressier Messier 6” f/8 Planetary Dobsonian features a well-designed freestanding Dobsonian mount with huge bearings for smooth motions and easy balance – aided by a rotating tube cradle. But the included finder and eyepiece are rather sub-par. However, it is still the best 150 mm freestanding (f/8) Dobsonian in the UK, and it’s ideal if you don’t want to deal with the hassles of collimation and coma with tabletop f/5 150 mm Dobsonians or finding a suitable table or another steady surface to set the tabletop scope on top of.
The SkyWatcher Heritage 150P is the non-computerised version of the SkyWatcher Virtuoso GTi 150P, with no other significant differences. The requirements, compromises, and benefits are all the same, except for the absence of the computerised system.
The Bresser Messier 6″ Tabletop Dobsonian is an excellent choice for those who must have a closed-tube 150mm tabletop scope and delivers a huge achievable field of view with its 2” focuser and short 750mm focal length if used in conjunction with the right wide-angle eyepieces. Compared to the Heritage 150P, it’s a bit heavier/bulkier and the provided eyepieces are not quite as good as what’s included with the Heritage 150P. But at the same time, you don’t need a shroud for it to work properly
The Ursa Major 6″ f/8 Planetary Dobsonian features a 150mm aperture with high-quality optics and is reasonably priced. Its f/8 focal ratio makes collimation easy, and its true metal Crayford focuser and spring-tensioned bearings allow you room to grow into heavier and more expensive eyepieces. But the maximum field of view is nowhere near as wide as an f/5 tabletop 150 mm Dobsonian, especially considering the scope’s 1.25″-only focuser.
What we don’t like about the Sky-Watcher Skyliner 150P Classic Dobsonian is that it has a poorly designed “brake” for its altitude bearings, its rack-and-pinion focuser is inferior to the Crayford design of the Ursa Major 6″, and the scope’s secondary mirror is too small to fully illuminate 2” eyepieces despite the focuser’s ability to take 2” eyepieces. However, on our tests, the included Super eyepieces were quite good, and optically, the scope is as good as the above two.
Celestron StarSense Explorer 150mm Dobsonian
£379 at FLO
The Celestron StarSense Explorer 150mm Dobsonian uses standard 150mm f/5 optics similar to the SkyWatcher Heritage/Virtuoso 150 tabletops and has a similar single-armed tabletop base. Considering that the similar-optic, fully computerised Virtuoso GTi 150P is quite a bit less expensive, we can’t really think of a good reason to go with the StarSense Explorer 150mm Dobsonian over the dozen picks ahead of it, though it certainly delivers excellent views and is aided by the easy-to-use StarSense Explorer smartphone app and technology.
Rank Category: 200 mm Dobsonians
For a beginner, the 8″ Dobsonian offers the best balance of aperture, portability, affordability, and simplicity. An 8″ Dobsonian is almost exactly the same physical size as a 6″ f/8 freestanding Dob, apart from the wider tube, but offers significantly more resolution and nearly double the light-collecting capability. 8-inch Dobsonians are usually the most recommended size for beginners and hobbyists and are made to last a lifetime. You may still want to consider a 10”, however, which offers a similar form factor to a 6” or 8” with even more capability.
The StellaLyra 8″ f/6 Dobsonian, manufactured by GSO and sold through First Light Optics—the most popular UK telescope retailer—offers great performance, as with any Dobsonian telescope of this aperture, and comes well-equipped with a variety of features and accessories which would easily double the cost of the telescope if sold separately, such as a 2″ dual-speed Crayford focuser, right-angle 9×50 finder and a pair of decent starter eyepieces. Among the telescopes we feature, this is the most bought one by our readers.
The Celestron StarSense Explorer 8″ Dobsonian is lighter and easier to carry than many other 200 mm Dobsonians; however, it lacks the accessories and features that the StellaLyra 8″ offers, apart from the hallmark Celestron StarSense Explorer technology, which allows for easy navigation of the night sky using a smartphone attached to the telescope.
The Bresser Messier 8″ Dobsonian features a very well-designed base with huge bearings for smooth motions and minimal balance differences when you swap out accessories, along with adjustable tube rings and a quality focuser. However, the provided accessories are fairly poor quality and need to be swapped out.
A low-cost 200 mm Dobsonian package, the Ursa Major 8″ f/6 gives you a lot of aperture for the price but is relatively lacking in features or more than an extremely basic set of accessories.
The Sky-Watcher Skyliner 200P Classic is a fairly basic 200 mm Dobsonian, with good views at the eyepiece, accessories that do the job, and a mount which is acceptable but doesn’t have the most well-designed tensioning system or smooth motions compared to some other offerings, though it’s still much better than a wobbly tripod.
The Sky-Watcher Skyline 200P FlexTube Go-To isn’t much more compact than a standard 200 mm (8″) Dobsonian, but its Go-To system provides smooth motorised tracking and the ability to locate any object in the night sky, and you can still aim the telescope manually thanks to Sky-Watcher’s FreedomFind encoder system. It is nice for those needing the most compact 200 mm dobsonian possible, but it comes at the cost of a higher weight, more frequent collimation, and stray light issues.
Rank Category: 250 mm Dobsonians
While a little less compact than smaller models, a 10″ Dobsonian provides even more brilliant views. Most of the 10” Dobsonians available in this price range are marginally heavier than an 8” and have the same length tubes, which means that portability-wise, a 10” is still plenty easy to manage. With most units possessing a 1200 mm focal length, it’s no trouble to fit one across the back of a vehicle. 10″ Dobsonians gather 56% more light compared to 8″ Dobsonians, and it is totally worth the upgrade if you don’t mind the extra bulk or cost. 8” is still the gold standard to many, but there’s little disadvantage to starting with a 10” telescope besides cost. You can also consider a truss tube option in lieu of a solid-tubed 10” Dobsonian, which can be portable and often affordable, with the drawback of increased setup time.
The StellaLyra 10″ f/5 Dobsonian is an upscaled version of the 200 mm StellaLyra model, with just a bit more aperture and weight but the same physical dimensions, accessories, and focal length. With 56% brighter views and slightly better resolution, the 250 mm is well worth the upgrade if you can afford it.
The Celestron StarSense Explorer 10″ Dobsonian features the same lightweight base, Celestron StarSense Explorer technology and simple accessory package as the 200 mm model. The StarSense Explorer technology really pays off at this aperture, allowing you to easily locate plenty of “faint fuzzy” deep-sky objects.
The Bresser Messier 10″ Dobsonian’s sturdy, buttery-smooth mount features rotating rings to adjust for balance and huge bearings to minimise jerky motions at high magnifications. The optics are, of course, excellent as well – but you don’t get much in the way of useful accessories apart from a low-quality finderscope and eyepiece.
The Sky-Watcher Skyliner 250P Classic is relatively simple and functional, as with its 200mm counterpart. The 250 mm of aperture provides better views than an 200 mm without any appreciable gain in weight or physical dimensions. The scope’s mount isn’t the most well-designed but is still fairly easy to aim and very sturdy, the accessories provided are decent, and the single-speed focuser does the job.
The Explore Scientific 10” Truss Dob is an expensive telescope, but it has many features that make it worth the cost. It is entirely metal in construction and can be very easily disassembled for transportation. Additionally, the scope comes with built-in cooling fans to help regulate its temperature. Unfortunately, no eyepieces are included, and the user will need to purchase a shroud in order to keep light pollution, the Moon and other sources of glare from interfering with performance. Assembly is also a little more complex than a standard tube Dobsonian.
The Sky-Watcher Skyliner 250P FlexTube isn’t much more compact or lightweight than a solid-tubed scope of this aperture and features the same basic design (and mechanical faults) as the regular Skyliner 250P. Unless you have some compelling reason to need to lose that little bit of tube length when stored, the regular 250P or a better 250 mm Dobsonian might be a wiser choice.
The Sky-Watcher Skyliner 250P FlexTube Go-To’s main selling point is not the FlexTube configuration but rather its motorised Go-To and tracking, which provides added convenience while not interfering with manual aiming at all thanks to the Sky-Watcher FreedomFind slip clutch and encoder system.
