Overview of AD8 Optical Tube
The Apertura AD8 Dobsonian telescope uses a standard borosilicate (Pyrex) primary mirror, which cools down to ambient temperature more quickly than standard BK7 or soda-lime plate glass, like the kind offered with most smaller and cheaper scopes. However, with extreme temperature differences (for instance, bringing the scope outdoors on a freezing night), it may take over half an hour to cool down, and thus a small battery-powered fan is installed on the back of the scope to speed that process up. The mirror is easy to collimate, but we’d recommend removing the “mirror lock” bolts from the back of the mirror cell. They are supposedly there to help the telescope retain collimation better during transport, but in practice, all they really do is make collimation more confusing, and if the telescope is dropped, they may slam into the mirror and crack it.
The plastic front cap included with the Apertura AD8 Dob tends to not fit very tightly, and if it does, it may become difficult to remove; you might want to attach some kind of a handle to it and line the edges with tape for a snug fit.
The tube of the AD8 is about 2” (5 cm) longer than the Synta-made Dobsonians sold by Sky-Watcher, Orion, and others. As such, it may not fit in the trunk or boot of some smaller vehicles and must be laid across the back seat.
The focuser on the AD8 is a well-made GSO dual-speed Crayford. It works by rolling the focuser draw tube against 4 rollers and a piece of Teflon (PTFE) plastic. The “dual-speed” aspect is a small 1:10 reduction knob on one side that allows for extremely fine focusing, down to just a few microns of adjustment – this is really helpful at high magnifications. The focuser uses a brass compression ring to grab your eyepieces and comes with a 1.25” adapter with its own compression ring as well.
Accessories Coming With The Apertura AD8
RECOMMENDED BUY FOR VALUE OFFERED
The Apertura AD8 Dobsonian includes a 9x50mm right-angle correct-image finder scope, a laser collimator, a “Moon filter”, and two eyepieces: A 2”, 30mm “SuperView” (40x) and a 1.25” 9mm Plossl (133x). At the price that the telescope is being offered, the package simply cannot be beat.
AD8 is a HighPointScientific exclusive
The Apertura AD8’s included 9×50 finder works, but on its own can be mildly frustrating to use to aim the telescope. You have to sight along the tube, then look into the finder to actually center the telescope on your target. This can be a bit confusing if you’re not familiar with the sky. Brighter deep-sky objects like the Andromeda Galaxy can be easily seen in the finder under light-polluted skies that make them invisible to the naked eye, along with stars down to 9th magnitude, but the confusion of using the 9×50 somewhat offsets these gains. A zero-power red dot or reflex sight is easier to use and can complement or replace the 9×50 finder.
The laser collimator included with the AD8 Dobsonian is supposed to make collimation a breeze. However, for one thing, the laser itself is frequently out of square with the barrel when it arrives, requiring adjustments with a hex key and being placed in some sort of makeshift V-block to confirm it is parallel, which may be a bit of a headache for a lot of beginners. Without this work, the laser is little more than a decoration. Seating it properly and squarely in the focuser is also very important, otherwise the laser may look dead on when your collimation is in fact quite far from correct.
The included 30mm SuperView is a great low-power eyepiece. You might notice that stars towards the edge are less-than-sharp; this is a combination of the coma inherent in any Newtonian telescope that’s f/6 or faster and some edge-of-field astigmatism with the eyepiece. You could buy nicer eyepieces that have sharper stars and wider fields of view and a coma corrector to eliminate the coma, but at that point you’d be spending nearly as much as the whole scope costs. Compared to the standard 25mm Plossl supplied with most other beginner scopes, the 30mm SuperView is a joy to use and is a great eyepiece for general viewing of deep-sky objects as well as finding them.
The included 9mm Plossl is rather short on eye relief. This means you have to press your eye quite close to it to get the full view. However, it’s quite sharp, and 133x is enough for some nice views of the planets. Overall, the 9mm Plossl is a nice little addition.
The included 1.25” “Moon filter” is complete junk – a piece of tinted green glass that dims the view at the expense of sharpness and turns everything green. It’s basically worthless.
The Almost Perfect Dobsonian Mount
The Apertura/GSO Dobsonians use roller bearings (essentially a “lazy Susan”) for azimuth (side-to-side) motion instead of the typical Teflon pads and laminate arrangement that most Dobsonians use. This approach works fine, but it can be a bit hard to get the right amount of motion—a lot of people tend to complain that the scope is too stiff or spins too freely, which can make aiming and tracking with the telescope at high magnification a bit frustrating. The scope is also prone to easily spinning around if it’s windy.
The Apertura AD8’s altitude (up/down) bearings are ball bearings which can be adjusted back and forth along the tube to compensate for the telescope’s changing center of gravity, depending on what eyepieces/finders/etc. that you prefer using. This can’t easily be done in the field, but it suffices for balancing with most stuff. You can also adjust the friction by tightening two large knobs on the bearings.
Like most mass-manufactured Dobsonian telescopes, the AD8’s mount is made out of melamine-covered particle board and can be assembled in a few minutes with the included hex key.
Should I buy a Used Apertura AD8?
A used Apertura AD8 Dobsonian is a wonderful scope. Make sure that the mirrors are reflective and you can’t see through them. Some dirt/grime is fine and can probably be cleaned, but coating damage means you’ll need the mirrors recoated, which easily negates any cost savings from buying used. A damaged base isn’t a show-stopper, however; making a new one out of plywood is relatively inexpensive and easy to do (and a plywood base actually weighs less than the original anyway).
The Apertura AD8 Dobsonian telescope is easily the best telescope in its price range, but if you must consider alternatives, here are a few we’ve selected:
- The Apertura AD10 (also sold as the Zhumell Z10 and Orion SkyLine 10) is basically a scaled up AD8 – same accessories, same features, and a similar physical size but with a larger aperture.
- The Sky-Watcher 8” Collapsible has similar optics to the AD8 but with a collapsible tube, a single-speed focuser, and lower quality accessories.
- The Orion StarBlast 6i has less aperture than the AD8 but includes Orion’s IntelliScope Digital Object Locator to easily find deep-sky objects (though it does not actually aim or track for you).
What can you see with Apertura AD8?
The AD8 can show you a lot of things. Saturn’s rings and Jupiter’s cloud belts are easy to spot, as are their moons. Saturn’s cloud belts, the Cassini division in the rings, and Jupiter’s Great Red Spot are a bit harder. On a steady and clear night, you’ll be able to see Jupiter’s moons as tiny disks with their shadows following them as they transit across the planet, an event that happens almost every night. Mars’ dark spots and ice caps can be seen when the Red planet is near Earth for a handful of months every two years, and with certain observing tricks, you might even be able to spot its tiny outer moon, Deimos. Venus and Mercury are devoid of detail – the former is covered in clouds and the latter is tiny, never high in the sky and lacks large high-contrast features – but you’ll be able to see their phases easily. Uranus and Neptune are bluish dots, their moons on the limit of visibility with dark skies – Neptune’s moon Triton is the brightest and thus the easiest at magnitude 13, followed by Oberon and Titania around Uranus at magnitude 14. With some effort, Ariel is also visible around Uranus, although it’s a bit harder than Oberon and Titania. Under dark skies, Pluto can just barely be seen with the Apertura AD8 as a star-like point, although for the next few decades it will be surrounded by thousands of stars of similar brightness and thus difficult to pinpoint.
Outside the Solar System is where the AD8’s aperture becomes even more helpful, though keep in mind that the quality of your skies (i.e. how dark they are) is extremely important when it comes to viewing “faint fuzzies”. Under dark skies with the Apertura AD8 dobsonian telescope, you can see details such as spiral arms, dark dust lanes, and nebulae (known as H-II regions) in spiral and irregular galaxies like M31, M51, M33, M82, M82, and many of the galaxies in the huge Virgo Cluster. Emission nebulae like Orion, the Lagoon, and the Swan look fantastic. With an aftermarket UHC or Oxygen-III filter, you’ll be able to see the Veil Nebula, which stretches across an area of sky several times the width of the full Moon. Planetary nebulae like the Ring and Cat’s Eye are bluish or greenish with lots of small details, and you’ll have no trouble resolving globular clusters into individual stars, even with fairly light-polluted skies. Open star clusters like the Double Cluster look magnificent and colorful no matter where you are.
Keep in mind that without dark skies, many galaxies lose their details or disappear from view entirely, while nebulae become a shadow of their former splendid selves and globular clusters lack sparkle and contrast. Thankfully, the AD8 is pretty portable and thus easy to transport to a good viewing location. Additionally, a properly cooled and collimated instrument along with steady skies are needed to get the best views of the planets, the Moon, and other small targets—the first two factors you can control, while the third depends on general location and luck.
Pricing and Availability
Because the Apertura AD8 is a HighPointScientific exclusive, there’s not much to consider in terms of pricing and availability besides checking the listing on HPS. Their prices are always competitive.