This Sky-Watcher Dobsonian has:
• fully multicoated 16” f/4.4 Newtonian reflector optics
• unique telescoping truss-tube design for compact transportability
• no-tool store-flat break-down of the rocker base for compact transportability
• smooth Teflon altitude bearings, plus altitude tension control
• low friction needle roller bearing assembly for azimuth motion
• dual speed 2" Crayford focuser with 1.25" adapter
• 10mm (180x) and 25mm (72x) 1.25” Plössl eyepieces
• 9 x 50mm straight through finderscope
With the 16” Sky-Watcher telescoping truss-tube Dobsonian, you don’t have to worry about lifting the scope’s diagonal mirror cage and trying to bolt it to swaying truss tubes in the dark as you do with other truss-tube Dobs. Sky-Watcher's revolutionary telescoping truss-tube system attaches the top of the truss tubes permanently to the diagonal mirror cage, with the bottom of the tubes sliding into three die-cast housings on the scope’s primary mirror tub.
This unique system allows the optical tube's diagonal mirror cage and three attached truss tubes to slide down onto the primary mirror tub and be locked in place to form one surprisingly compact assembly. By undoing the no-tool handles in the sides of the altazimuth base that hold the optical tube in the base, the cage and tub assembly can be lifted out of the scope’s altazimuth rocker base as a single unit for easy and secure transport.
In addition, the vertical sides of the altazimuth base can be disassembled in minutes from the circular ground board/azimuth bearing assembly for easy lay-flat transport. No-tool hand-tighten knobs and threaded inserts in the base and vertical sides allow fast assembly and disassembly in the field.
Preparing the Sky-Watcher Dob for use involves assembling the base, lowering the collapsed optical tube into the base , then simply unlocking the diagonal mirror cage and raising the cage until spring-loaded catches on the truss tubes snap into place in the primary mirror tub. This holds the cage in its fully-raised position while you tighten the no-tool handles at the base of the truss tubes to lock the diagonal mirror cage securely in position for observing.
For binoviewing without unwanted extra magnification, a second set of indents on the truss tubes allows the diagonal mirror cage to be lowered to a preset locking position on the truss poles. This lets you to use a binoviewer without needing a corrector or Barlow lens in the binoviewer to reach focus.
The Sky-Watcher easily collapses in minutes into two components. They will fit into the back seat of a most cars and into the back of an SUV or crossover, although the altazimuth base may have to be broken down to lie flat in some vehicles.
Assembly and disassembly take only 20-25 minutes or so, with no tools needed. After you set up, particularly after traveling over bumpy roads to a dark sky site, take a few moments to check the collimation of the optics to assure peak performance and you are ready for an evening of fascinating viewing at your favorite dark sky location. If observing from your back yard, you can leave the scope assembled and simply roll it outside using a hand truck or a JMI Wheeley Bar.
The 16” Sky-Watcher telescoping truss-tube Dobsonian is designed for visual observing only – to show you as much of the night skies as possible, and do it as conveniently and inexpensively as possible. Photography is not possible with a Dob.
The optical tube weighs 72 pounds (32.7 kg) and the completely assembled altazimuth base weighs 88 pounds (40 kg). One suitably-motivated and fit individual can transport and set up the 16” Sky-Watcher telescoping truss-tube Dob, although two people will certainly make the task easier. Its innovative and unique telescoping design and easy break-down base give Sky-Watcher users a cost-effective 16” telescope with unsurpassed compactness and transportability.
This Sky-Watcher Dob’s Optical Tube Assembly . . .
- Newtonian reflector optics: 16” diameter parabolic primary mirror, guaranteed to be diffraction-limited. The diagonal mirror cage and primary mirror tub are made of aluminum, anodized and finished externally with a subtle and attractive star-field pattern. Painted die-cast and machined rims hold the aluminum truss tubes and optical components in precise alignment to minimize the need for frequent collimation.
- Primary mirror: Grade A annealed optical glass, 16” diameter, 1800mm focal length, f/4.4 parabolic. The mirror is conical in shape, thinner towards the edges than at the center where it mounts on its fully adjustable metal cell. This conical shape reduces both the weight of the mirror and the time the mirror takes to cool down to ambient temperature for best observing. The mirror provides sharp and bright high contrast images of nebulas, galaxies, and star clusters. Lunar and planetary images are also sharp and crisp, but a neutral density (Moon) filter would certainly be called for to cut down on the incredible solar system brightness provided by this 16” mirror – over 3300 times that of your eye. The center-spotted mirror is ground with computer-controlled accuracy, multicoated with aluminum and titanium dioxide for high reflectivity, and then overcoated with quartz for long life.
- Diagonal mirror: Grade A annealed optical glass 3.94" m.a. diagonal mirror, mounted in a fully adjustable diagonal holder on a low-diffraction four-vane thin spring steel spider. The diagonal mirror is polished flat to diffraction-limited accuracy. As with the primary mirror, the diagonal is multicoated with aluminum and titanium dioxide for high reflectivity and overcoated with quartz for long life.
- Finderscope: 9 x 50mm straight-through achromatic dark crosshair design.
- Focuser: dual-speed machined aluminum 2” Crayford focuser with a 1.25” eyepiece adapter.
- Eyepieces: 10mm and 25mm 1.25” four-element Plössl eyepieces with a 52° apparent field. The 25mm provides a magnification of 72x with an actual field of view 0.72° across. That’s nearly one and half times as wide as the full Moon. The 25mm gives rich and expansive deep space views of star clouds, galaxies, and nebulas alike. The 10mm Plössl provides a stout 180x magnification with a 0.29° field of view, enough magnification to provide sharp close-up views of the Moon, planets, globular star clusters, multiple star systems, and more.
- Optical Tube Dimensions: The telescoping 16" optical tube measures 19.25" (489mm) in diameter from the outside of one side bearing to the outside of the other, 66.75" (1695mm) long when extended, but a much more compact 42.5" (1079mm) in length when closed. The eyepiece is approximately 68" above ground level when the optical tube is pointed at the zenith.
This Sky-Watcher Dob’s Base Assembly . . .
- Rocker box altazimuth base: The altazimuth rocker box that the mirror tub rides in is crafted of strong, lightweight, and water-resistant 25mm thick laminated particle board, as is the water-resistant ground board that the rocker box rides on. The extra thick construction (25mm thick components versus 19mm on the 12" and smaller Dobs), plus reinforcing ribs on the sides of the base, provides maximum rigidity and stability for this 16" scope. The base is shipped disassembled, but can be put together in about a half an hour using only the supplied no-tool knob hardware. Once assembled for the first time, subsequent break-down for transport and reassembly in the field will only take 10-15 minutes. Teflon bearings in altitude and needle roller bearings in azimuth provide smooth and effortless motion of the optical tube in all directions.
- Navigation knobs: Navigation knobs conveniently mounted below the focuser make it easy to control the scope’ motion in any direction and provide convenient grips for carrying the complete optical tube and extending the mirror cage when setting up for use. The optical tube starts moving at a gentle touch – smoothly and with no fuss. Center on an object and the scope settles down immediately, with no shudder or vibration to mar your viewing experience.
- Carry handles/altitude tension control/eyepiece tray: Two handles in the sides of the base make moving the scope easier. The separate tube-like handles in the sides of the rocker box that hold the optical tube in the base incorporate a tension control in altitude that lets you compensate for eyepieces of markedly differing weights. An eyepiece tray capable of holding one 2” and three 1.25” eyepieces attaches to the front of the rocker box.
- Altazimuth base dimensions: 32.5" in diameter by 33.5" high when assembled, 32.5" in diameter by 9.5" high when broken down for transport.
What can you see through the 16” Sky-Watcher telescoping truss-tube Dob?
Everything in deep space appears brighter, and wider in extension, with the 16” Sky-Watcher. You now have the tremendous light gathering power to see the faint and distant nebulas and galaxies that you have always wanted to see for yourself – over 3300 times that of your unaided eye.
The advantages of the scope’s large aperture are immediately apparent, particularly to the experienced observer with an eye trained to see extremely fine detail. Color becomes visible to the eye in many nebulas. Orion is a glowing blue-green mass of filaments, often tinged with red and yellow for the keen-eyed observer from a dark sky site. Globular clusters can be resolved to their cores, with each cluster becoming a vivid ball of tiny starpoints instead of a hazy blur. Knottings and structure in the arms of the Whirlpool Galaxy (M51) become clear. Mighty globular clusters in the distant Andromeda Galaxy (M31) may begin to approach the threshold of visibility for the exceptionally keen-eyed observer. Small details in the atmospheres of Jupiter and Saturn and on the surface of Mars reveal themselves at high powers (given suitably good seeing and a filter to cut down the immense brightness of a scope with over 3300 times the light-gathering capacity your eye).
The more obscure Messier and NGC objects (such as planetary nebula NGC 3242 in Hydra, spiral galaxy M100 in Coma Berenices, and open cluster NGC 6231 in Scorpius) show a heightened level of resolution invisible in smaller scopes. Difficult low surface brightness objects like the Crab Nebula (M1) in Taurus, the face-on Spiral Galaxy (M33) in Triangulum, and the Owl Nebula (M97) in Ursa Major begin to show their essential structures under high-power visual observation. The list goes on and on, and you will delight in planning your own nightly journeys of exploration.
As with any large aperture telescope, the performance of the 16” Sky-Watcher on faint objects will be markedly improved by a dark sky observing site. Light-polluted city and suburban sites are definitely not recommended as the primary observing site for a 16” scope. Such sites require a nebula (light pollution) filter to take even limited advantage of its immense light-gathering.
Taking advantage of the space-saving sophistication of its telescoping truss-tube design, the 160 pound Sky-Watcher 16” Dobsonian makes it practical to transport this truly big scope to a favorite dark sky observing site. It certainly helps to have a friend to share the set-up – but a suitably motivated and fit individual can do it on their own. Either way, this Sky-Watcher 16” telescoping truss-tube Dobsonian reflector will keep you happily observing the faint and distant outer reaches of the Universe for many years to come.