The Optical Tube
The StellaLyra 10″ f/5 Dobsonian telescope’s primary mirror is a 250mm (10”) f/4.9 unit with a resulting 1250mm focal length. It is made of ordinary BK-7 optical glass, which cools down to ambient temperatures from a warm room at a decenly fast pace, allowing for it to acclimate for the sharpest possible views slightly faster than soda-lime plate glass but not as fast as borosilicate/Pyrex glass. If the temperature changes noticeably, you may need to allow the telescope to acclimate to the cold by leaving it outside for a while or sticking to low power before using it at high magnifications that demand the best possible image quality. The scope features a built-in, battery-powered fan that can speed up the process, but it’s essential to turn off the fan while looking through the telescope to prevent vibrations from affecting the image quality.
Collimating the StellaLyra 10″ f/5 Dobsonian is easy, and the secondary mirror rarely needs adjustment. The primary is on a simple spring-loaded mirror cell which can be adjusted without tools. It’s advisable to remove the included “locking bolts” as they are not necessary and may even crack the mirror if the telescope is dropped or hits something hard. However, the stock springs in the mirror cell are not very rigid and can lead to collimation shift without the locking bolts/knobs in place, and as such you will need to replace those as well. Some users have repurposed the threaded holes where the lock bolts go to attach rubber feet, making it easier to stand the telescope tube upright during setup or storage. The secondary mirror of the StellaLyra 10″ f/5 Dobsonian requires a hex key for adjustment, but it should rarely need it. Replacing the hex screws with thumb screws is not recommended as they can come loose more often.
The StellaLyra 10″ f/5 Dobsonian is equipped with GSO’s standard 2-inch dual-speed Crayford focuser, which is commonly used with various Dobsonian, Newtonian astrographs, Cassegrains, and Ritchey-Chretien instruments. The Crayford focuser operates by rolling the focuser draw tube against a set of four rollers and a Teflon (PTFE) plastic strip, without any gears or teeth besides the planetary gears in the 10:1 speed reduction knob used for fine focusing. The focuser has a brass compression ring that holds your eyepieces securely without scratching them, and it also includes a 1.25-inch adapter with filter threads and a compression ring fitting.
The optical tube of the StellaLyra 10″ f/5 Dobsonian telescope fits across the back seat or in the boot of many vehicles, and is actually shorter than some 8-inch Dobsonian models. You do not need to purchase a case or bag for the StellaLyra 10″ f/5 Dobsonian telescope. Wrapping it in a towel or coat is sufficient if you’re worried about damaging the tube, and it is easier to carry and store the scope without a bulky case. With an overall weight of 15 kg, most people should not have difficulty moving the tube, although its size and smooth metal surface can make it awkward. Some people opt to purchase or create lifting straps or add additional handles to make carrying it easier.
The StellaLyra 10″ f/5 Dobsonian telescope comes with a 9x50mm right-angle finder scopeand two eyepieces: a 2-inch, 30mm focal length “SuperView” (42x) and a 1.25-inch, 9mm Plossl (139x).
The included 30mm SuperView 2-inch eyepiece, providing 42x with the StellaLyra 10″ f/5 Dobsonian, is excellent for low magnification. The apparent field of this eyepiece is approximately 68 degrees. The stars at the edge of the field of view with the SuperView and similar cheap wide-angle oculars may appear distorted into “seagulls” or cross-like shapes in the StellaLyra 10” f/5 Dobsonian due to a combination of the telescope’s inherent coma, which affects all faster Newtonians, and the SuperView’s optical design; the simple 5-element Erfle optical configuration thatthe SuperView uses is not actually designed for telescopes faster than f/6. Nonetheless, the SuperView offers significantly sharper and wider views than a standard 25mm Plossl or Kellner eyepiece and is more comfortable to look through than those designs.
The other eyepiece provided with the StellaLyra 10″ f/5 Dobsonian, a 9mm 1.25-inch Plossl, provides 139x magnification. It has limited eye relief, requiring you to press your eye against it to take in the whole field of view at once, even though the apparent field is only approximately 45 degrees, narrow by any standard and almost claustrophobic compared to the SuperView’s 68-degree apparent field. Nonetheless, it is quite sharp and offers a good magnification for viewing small targets such as the Moon, planets, double stars, globular clusters, and planetary nebulae. However, on a clear night, the StellaLyra 10″ f/5 Dobsonian can handle much higher magnification with additional eyepieces.
Even under heavily light-polluted skies, the well-made 9×50 finder performs exceptionally well, revealing many fainter stars that the human eye cannot see, as well as many of the brightest deep-sky objects. However, beginners may find it challenging to use to coarsely aim at a target since you cannot look up at the sky and through the finder at the same time, while the crosshairs are difficult to see in the dark. It takes some practice to sight along the tube and then glance through the finder to locate your target without overshooting it significantly. You may want to supplement or replace the 9×50 finder with a red dot finder, Telrad, or similar zero-power reflex sight if you find it difficult to use.
The StellaLyra 10″ f/5 Dobsonian is an alt-azimuth-mounted telescope like all Dobsonians. The telescope moves up and down on two side bearings that are attached to the tube, and swivels sideways by spinning the top part of the base against the bottom. However, unlike other Dobsonians that use plastics, the StellaLyra 10″ f/5 Dobsonian uses bearings similar to those found in industrial machinery.
For side-to-side motion, the StellaLyra Dobsonians use roller bearings, which function like a “lazy Susan” with tiny plastic rollers between the telescope’s ground board and the bottom face of the rocker box. This system is cheap, smooth, and largely effective but can be loose and easily spun on a windy night, or simply cause you to overshoot your target when adjusting where the telescope is pointed. Likewise, tightening the center bolt can make motions overly sticky and hard to control. It’s hard to get the exact degree of friction needed which is why Dobsonians usually use Teflon bearings gliding against a laminate surface like the melamine already covering the StellaLyra’s base. Replacing the lazy Susan with furniture glides or PTFE (Teflon) pads like ordinary Dobsonians use is a cheap and easily implemented fix.
The StellaLyra 10″ f/5 Dobsonian’s altitude bearings are sealed ball bearings with large plastic knobs to adjust friction, which impacts the ease of moving the telescope up/down in the sky. The bearings can be cranked tight to lock the telescope in place for storage or when swapping out heavy accessories. You can also slide them along the tube depending on where the center if gravity is with your usual accessory setup. It is best to set both bearings’ position ahead of time indoors, as adjusting them evenly in the field is challenging.
The StellaLyra 10″ f/5 Dobsonian’s base weighs around 13 kg, thanks to its use of particle board instead of actual wood material, and as such is more dense and awkward to move around than it might appear to be at first glance. The base arrives flat-packed and can be assembled quickly with the screws and tools provided. However, regular use can damage the particle board base, and moisture can cause it to deteriorate, worsened if you live in a humid environment or simply mistreat it. If this happens, you can make a replacement out of plywood with fairly basic carpentry tools. In addition to the durability improvements, replacing the stock particle board base with a lighter plywood one can make it more manageable for those who would otherwise find the weight and size a detriment to setting up or using it. Alternatively placing the scope on a cart or dolly works too.
Should I buy a Used StellaLyra 10″ f/5 Dobsonian?
If you’re looking for a high-quality beginner telescope at a reasonable price, a used StellaLyra 10″ f/5 Dobsonian is as good of a choice as a new scope if you can find one available, and will give you extra budget to put towards accessories. When purchasing a used unit, keep an eye out for damaged mirror coatings or a damaged base. A damaged base is relatively easy and inexpensive to replace, and a homemade one may provide additional benefits as previously mentioned, but damaged mirror coatings can be a bigger problem. If the mirror appears dull, cleaning may be all that’s needed. However, if there is obvious moss or spider-like chemical corrosion, pinholes, or a transparent look to the coating, recoating the mirror may be necessary, which can be costly. Consider the cost of recoating versus the cost of buying a new instrument before making a decision.
Don’t worry too much about dents to the tube of any used Dobsonian – they’re almost inevitable and most don’t affect the light path. If any dents do impact the optics, they can often be removed with tools like those used to remove dents on a car, or even with a plunger or hammer in some cases.
Overall, the StellaLyra 10″ f/5 Dobsonian is one of the best beginner telescopes available, offering excellent quality and value for its price – but you may want to consider some other options among Dobsonians nonetheless, including larger, smaller, and truss/collapsible tube or motorized options.
- The StellaLyra 8” f/6 Dobsonian offers the same fantastic accessories, features, and attention to detail as its larger 10” counterpart, though it’s not much more lightweight or compact and significantly outperformed by the larger StellaLyra 10” f/5 Dobsonian.
- The Explore Scientific 10″ Ultra Light Dobsonian is much more compact than the Stellalyra 10” f/5 Dobsonian on account of its full truss design, while the all-metal structure is durable and the scope’s bearings are silky-smooth thanks to their glassboard-on-Teflon surfaces and the ultra-large altitude bearings eliminate concerns about balance with heavy accessories. The focuser is a nice dual-speed Crayford, too. However, few accessories are provided, you’ll also need a shroud to cover the exposed trusses, and assembly can be a bit more time-consuming compared to a solid-tubed instrument like the StellaLyra.
- The Celestron StarSense Explorer 8” Dobsonian is a lightweight and convenient 8” Dobsonian which uses Celestron’s StarSense Explorer technology to aid in navigating the night sky. Being an 8” scope it of course can’t show you as much as a 10”, however, while the design of the mirror cell makes collimation more difficult than it should be and the included accessories are quite sparse.
- The Sky-Watcher Virtuoso GTi 150P telescope is a compact and affordable tabletop Dobsonian, which comes with a fully motorised, tracking GoTo mount that can be managed by your smartphone or adjusted manually using its innovative FreedomFind encoders. While it’s limited in performance by its smaller aperture, it certainly offers great value for money. Another choice to consider is the manual Heritage 150P which has the same design and optics, but without any electronic components.
- The StellaLyra 12″ f/5 Dobsonian offers even more impressive views than its 10” or 8” counterparts due to its large aperture. However, moving this scope can be quite difficult without a dolly or large vehicle. If you have a big enough budget for a telescope like this and are worried about portability, then you might want to think about investing in an collapsible or truss tube 12” Dobsonian model instead.
- The Explore Scientific 12″ Ultra Light Dobsonian boasts a dual-speed Crayford focuser and an all-metal truss structure which makes disassembling it for transportation simple. Its movements are impressively smooth thanks to its high-quality glassboard and Teflon bearing surfaces and oversized D-shaped altitude bearings to prevent any issues with balance even with the heaviest eyepieces/accessories. Unfortunately, however, this scope lacks useful eyepieces or a good finder, so these will need to be purchased separately along with accessories such as a shroud to keep stray light out of the tube.
- The Sky-Watcher Skyliner 300P FlexTube proves easier to transport than solid tube scopes like the StellaLyra 12” as well as simpler to set up than truss telescopes; albeit with a questionably designed Dobsonian mount with undersized non-adjustable altitude bearings, which will inevitably lead to balance problems when pairing this telescope with heavy wide angle eyepieces or a coma corrector.
- The Celestron StarSense Explorer 10” Dobsonian is lightweight and easy to move around, while also making use of Celestron’s StarSense Explorer technology in order to locate deep sky objects quickly without the use of expensive and bulky motor drives – though does lack the ability to even upgrade to a dual-speed focuser as well as including only a red dot finder and a single eyepiece for accessories.
- The StellaLyra 16″ f/4.5 Dobsonian provides incredible deep-sky views with the same basic design, accessories, and features as the 10” StellaLyra with the additions of a truss tube which can be dismantled for storage/transport as well as of course a monster 16” of aperture.
- The Sky-Watcher Skyliner 350P FlexTube Dobsonian’s 14” of aperture isn’t quite as capable as the StellaLyra 16” but still boasts a considerable performance advantage over a 10” or 12” Dobsonian and is quite simple to set up, though its mount is not exactly the most weight-efficient or well-designed and the FlexTube format still makes for a rather bulky and awkward-to-move tube when collapsed.
- The Sky-Watcher Skyliner 300P FlexTube GoTo Dobsonian is a 12” Dobsonian which features full motorised tracking, with the Sky-Watcher FreedomFind encoder system enabling manual aiming nonetheless and the FlexTube design reducing the size of the scope when not in use, though it’s still quite heavy – especially thanks to the additional weight imposed by the motor drives.
- The Sky-Watcher Skyliner 250P FlexTube GoTo Dobsonian has similar performance to the 10” StellaLyra Dobsonian but with the addition of motorised GoTo/tracking as well as the Sky-Watchere FreedomFind encoders to allow for manual aiming. The FlexTube design does not significantly reduce the size of this scope but is appreciated nonetheless.
Aftermarket Accessory Recommendations
The StellaLyra 10″ f/5 Dobsonian includes an appealing set of accessories to initiate your stargazing experience, and it’s one of few telescopes where you can get by without shopping for any extra equipment right away. However, you’ll definitely benefit from a few additional eyepieces. A 7mm UWA (179x) and/or a 4mm UWA (313x), both boasting an impressive 82-degree apparent field of view, will permit the StellaLyra 10″ f/5 Dobsonian to attain higher magnifications than the 139x you get with the included 9mm Plossl. A 7mm or 4mm planetary eyepiece will also do if you’re on a budget, though the field of view achieved with either is much less and you’ll find yourself having to make adjustments to stay on target far more frequently.
Additionally, a 16mm UWA (78x) eyepiece serves as a suitable intermediary between the provided 30mm and 9mm eyepieces. A 15mm redline (83x) also works, though it’s not quite as sharp and the field of view is not quite as vast as a UWA eyepiece. We would also highly recommend you purchase a reliable Cheshire collimation tool to guarantee that your StellaLyra Dobsonian produces the sharpest images possible, as accurate collimation is critical at f/5.
While the StellaLyra’s included 9×50 finder is helpful for zeroing in on your target, many users may encounter difficulties when aiming the StellaLyra 10″ f/5 Dobsonian using solely the provided 9×50 right-angle finder scope. This is because it is not particularly intuitive to aim the telescope coarsely with a right-angle finder since you can’t actually see the sky and look through the finder scope at the same time. A popular and highly recommended solution to this issue is either to replace the finder scope entirely or, alternatively, to supplement it with a Telrad zero-power reflex sight.
It’s also worth considering the addition of a good quality UHC/OIII nebula filter to your collection of accessories for the StellaLyra 10” f/5 Dobsonian. A filter will increase contrast on nebulae such as the Orion Nebula when employing nearly any telescope, by dimming the background sky to bring out faint detail otherwise lost to background sky glow, which can be especially helpful under light-polluted conditions. A nebula filter also increases the visibility of planetary nebulae by lowering the apparent brightness of surrounding stars, making it easy for you to spot them at low magnification. Furthermore, under dark skies, a nebula filter’s contrast improvement can even expose previously unseen nebulae, like the Crab Nebula, Crescent Nebula, Veil Nebula, or Flame Nebula, with the StellaLyra 10” f/5 Dobsonian at low magnification.
What can you see?
The StellaLyra 10″ f/5 Dobsonian is a highly capable instrument, thanks to its large aperture and top-notch optics. It’s a common misconception that the “light bucket” status of big Dobsonians only helps on deep-sky objects or is somehow tied to poor optical performance; in reality, not only are most modern Dobsonians good optically but their huge aperture also enables greater resolution on small targets such as the planets and details on the Moon. However, telescopes larger than 12-14″ are rarely able to fully utilize their resolution capabilities due to atmospheric conditions most of the time.
The visibility of objects outside the Solar System, known as deep-sky objects, strongly depends on the light pollution conditions. Galaxies are particularly affected. Under a dark sky, the StellaLyra 10″ f/5 Dobsonian will reveal details in thousands of galaxies, including the beautiful spiral arms of M51 or the dust lanes of M82 and M31. However, under a city sky, only the brightest galaxies can be seen as pale, dim fuzzy spots, with little to no detail visible except for the occasional dust lane or elongated ovoid shape no matter how big and powerful your telescope is.
Emission nebulae like Orion (M42) look stunning with the StellaLyra 10″ f/5 Dobsonian, especially under dark skies and/or with a suitable UHC nebula filter. Dozens of colourful blue and green planetary nebulae like the emerald-hued Cat’s Eye Nebula are also visible with a 10” Dobsonian, along with larger ones like M27 (the Dumbbell) and M57 (the Ring). The telescope is also capable of resolving several dozen globular clusters, including most of the ones in the Messier catalog. Thousands of beautiful open star clusters can also be observed, ranging from the gigantic Pleiades (M45), with their faint glimmer of reflective dust visible under dark and clear skies, to small and obscure open clusters from the NGC or IC catalogs that may be embedded within larger targets. Plus, there’s always double stars, tens of thousands of which are resolvable, and many of which have interesting colours.
Regarding Solar System targets, you’ll be able to see the phases of Mercury and Venus, but little else. Mercury is rarely visible when it’s high in the sky and has few high-contrast features, while Venus’ cloud deck obscures its near-molten surface. However, some observers can see striations and dark markings in the clouds on occasion. The Moon shows details less than a mile wide, but the Apollo landing sites cannot be seen. On Mars, you’ll see an ice cap or two, and if there’s a global dust storm, you’ll see it. Under optimal conditions when Mars is closest to Earth, you can spot dozens of dark markings or even Olympus Mons with a skilled eye and steady air, but most of the time only a few surface features at visible even during a favorable apparition of the Red Planet.
Jupiter’s cloud belts are easy to observe with the StellaLyra 10″ f/5 Dobsonian, and its moons are visible as tiny disks, though seeing details on any of them is a job for a larger instrument. Shadow transits of the moons across the face of Jupiter occur regularly, and the Great Red Spot is also easy to observe. Saturn’s rings are similarly easy to spot, as is the Cassini Division within them and some faint cloud bands on the planet itself. Around half a dozen of Saturn’s moons are visible with the telescope, with Titan appearing as a visibly gold disk. On a very good night, the much narrower Encke gap in Saturn’s rings can also be seen. You’ll also be able to resolve Uranus as a teal dot, and up to 4 of its moons are visible under a dark sky on a steady night. Neptune is a bluish orb with Triton fairly visible even under mediocre conditions, while Pluto can be seen as a star-like point under dark skies with the StellaLyra 10” f/5 Dobsonian if you can narrow it down from the thousands of faint stars near it which appear identical.