A Dobsonian telescope offers the best optical performance for your money. 90% of the value are concentrated in the optical tube assembly (mirror cell, focuser etc.). So you get much aperture for an affordable price. The GSO GS880 Dobsonian reflector telescope combines powerful 254mm-diameter (10") reflecting optics with point-and-view simplicity that even a child can use. It shows you faint deep space objects that are simply invisible in smaller scopes. With a visual limiting magnitude of 14.5, the GSO GS880 is ideal for observing faint nebulas, galaxies, and star clusters from a dark sky site – all the faint fuzzies outside the solar system that fascinate us. At Thai Excite, a Dobsonian is no dead-end-street. We offer all possible optional equipment like tripods and mounts, dozens of eyepieces, and even equipment for astro photography.
The GSO GS880 houses a big 254mm parabolic mirror with 56% more light grasp than a 8" mirror and nearly 3x more light than any 6" telescope, for brighter, more detailed views of night sky curiosities. GSO mirrors are extremely well figured and are guaranteed to be difraction limited - for sharp high contrast images of nebulas, galaxies, and star clusters. Planetary images are also sharp and crisp, although a neutral density filter is often required to allow glare-free observing. The mirrors are overcoated with quartz for long life.
Under dark skies, the 10" aperture of the GS880 turns the Orion Nebula into a glowing and subtle complex of filaments, and color starts to become visible. The spiral structure of the Whirlpool Galaxy becomes apparent, as do dark dust lanes across the nucleus of the Andromeda Galaxy (although the full 3° width of the galaxy itself is far too large to fit into the field of view of any eyepiece generally usable with the scope). Globular clusters are frequently resolved to the very core. Messier, NGC, and IC objects show detail and structure never visible in smaller telescopes. The diffraction limited quality optics from GSO will at the same time offer razor sharp images even at high magnifications. Planets and the moon will be seen in great detail. The visibility of details is not limited by the telescope, but rather by observing conditions! As with any serious telescope, the performance of the 10" GS880 on faint objects will be improved by a dark sky observing site.
While it is in deep space observing of galaxies and nebulas from a dark sky observing site that this 10" GSO Dobsonian excels, significant planetary and lunar observing is also well within its capability. All you need is to use the included neutral density Moon Filter to cut down the immense brightness of solar system objects seen through this “light bucket."
The streamlined Dobsonian telescope base offers unflinching stability yet easy portability. While the telescope may appear bulky, it is actually quite easily portable to move around your backyard or to a dark sky site, since it can be separated into two main sections: the optical tube (1220mm x 305mm), and the Dobsonian base (560mm x 635mm). GS880 weights only 60 lbs (27kg) fully assembled. Putting the 2 parts back takes just a moment, with no tools needed. Simply lift the optical tube, rest its circular altitude bearings in the semi-circular cutouts in the sides of the rocker box, put in an eyepiece, and you're ready to observe.
Simply-made, but with precision Newtonian optics, this GS880 10" Dobsonian reflector will reward you with bright deep space and solar system views and years of trouble-free observing enjoyment.
GSO GS880 Optical Tube Assembly (OTA) Features
Primary mirror: 10" (254mm) diameter, 1250mm focal length, f/5 focal ratio. Parabolic mirror. The mirror is made of B270 “water white" optical crown glass that is free of internal stress and striae. B270 glass is equivalent to BK7 in performance and optical quality. The thermal stability of B270 glass is generally better than the soda lime float glass used for the mirrors of most reflectors in this reasonable price range. The mirror is ground and polished under computer control for guaranteed diffraction limited performance, coated with 94% reflectivity aluminum, and overcoated with a protective layer of silicon dioxide (quartz) for long life.
Primary mirror cell: Fully adjustable 3-point flotation system metal cell holds the primary mirror. The open frame of the cell allows the mirror to cool down to ambient temperatures quickly, so you can start observing sooner. Large hand-tighten color-coded push-pull collimation and collimation lock knobs make it easy to collimate the primary mirror with no tools required.
Primary mirror cooling fan: A lightweight 4.7" diameter low-vibration cooling fan is built into the mirror cell to assure faster cool-down times. The battery-operated fan is powered by a battery pack that uses eight user-supplied AA batteries and plugs into a jack on the mirror cell frame.
Diagonal mirror: 63mm m.a. B270 “water white" optical crown glass, coated with 94% reflectivity aluminum and overcoated with a protective layer of silicon dioxide (quartz) for long life.
Diagonal mirror support: Fully adjustable diagonal holder mounted on a low-diffraction four-vane thin spring steel spider.
The GSO GS880 also allows you to calibrate your mirrors to obtain the highest quality images that the telescope mirror is capable of. Use a philips (cross-head) screw driver to keep both primary and secondary mirrors in alignment. Such screws makes it easy to get the best out of your GSO GS880 telescope which has great reputation for its best-in-class mirrors.
Focuser: Dual-speed 2" Crayford type, with 1.25" eyepiece adapter. The machined aluminum focuser has dual coarse focusing knobs for smooth and precise image control with either hand. There is a separate 10:1 reduction ratio microfocus knob for ultra-fine focusing at high magnifications. The ribbed focus knobs are easy to operate, even while wearing gloves or mittens in cold weather. A 35mm extension tube for eyepiece use is standard equipment. The extension tube, and both the 2" eyepiece holder and the 1.25" adapter use non-marring soft brass compression rings to hold eyepieces in place, rather than simple thumbscrews that can scratch your eyepiece barrels.
Two eyepieces: One is a fully multicoated 2" 30mm (42x) 68° field SuperView eyepiece with a wide 1.6° actual field of view that's almost three and a half times the diameter of the full Moon. The second is a fully multicoated high power 1.25" 9mm (139x) 52° field Plössl.
Eyepiece rack: A standard equipment eyepiece rack attaches to the side of the scope's altazimuth base. It has cutouts to hold one 2" eyepiece and three 1.25" eyepieces.
Finderscope: 8 x 50mm straight through fully-multicoated dark crosshair achromatic design. The finder has a long and comfortable 13mm eye relief. It focuses by loosening the trim ring behind the objective lens cell, screwing the lens cell in or out to focus, and tightening the trim ring to lock in the correct focus.
Finderscope bracket: The 8 x 50mm finderscope mounts in a quick release bracket that slips into a pre-installed metal mounting shoe beside the focuser. The bracket is held in place in the mounting shoe by a single large hand-tighten chrome-plated knob that maintains the finder's collimation, even if the finder is removed between observing sessions.. The bracket has two hand-adjust collimation screws that work in conjunction with a third spring-loaded post in the bracket. This makes collimation faster than the traditional three- or six-screw collimation methods used with conventional finder brackets.
GSO GS880 Mount Features
The GSO G880 is easy to use - just point, release and observe. Vertical adjustment is aided by the tension control system described below. Here, you can adjust for the stiffness in this axis and even lock it. The GSO GS880 Dobsonian telescope comes equipped with a smooth 2" craford focuser with a 1.25" adapter, thus allows for use of both 1.25" and 2" accessories. It has a removable telescope eyepiece rack, a altitude clutch to hold scope in position, two telescope eyepieces, a moon filter, and a comfortable 8x50 correct-image finder scope. With accessories like these included, you're ready for night after night of family stargazing fun right out of the box!
Altitude ball bearings: Horizontal and vertical adjustment of the GSO GS880 Dobsonian telescope is very easy. Instead of the usual large circular trunnion bearings riding on a few Teflon pads in the semi-circular cutouts in the altazimuth base, this GSO 10" GS880 Dob uses innovative sealed metal ball-bearing systems to provide smooth vertical motion of the optical tube. The aluminum bearing housings fit snugly into cutouts in the sides of the altazimuth base. Because the bearings are sealed systems, the elements cannot affect the smoothness of the GS880's vertical motion, as it can when dust and grit invariably get trapped between the exposed trunnions and Teflon pads of conventional Dobsonians and scores the surfaces. The vertical motion of the GS880 tube is consistently ball-bearing smooth. And the sealed ball-bearings will not have to be replaced regularly, as is the case with the Teflon pads of many Dobsonians when wind-borne grit degrades the Teflon/trunnion interface.
Altitude clutch: Large ribbed clutch knobs are built into the two altitude bearings. A gentle twist on either knob adjusts the amount of friction within the altitude ball-bearing systems. This allows you to keep the focuser from rising or sinking when changing between eyepieces of considerably different weights, as for instance when switching between 1.25" and 2" eyepieces.
Tube balance system: The altitude bearings of the GSO GS880 are bolted to slotted plates attached to the optical tube. This allows the optical tube to be moved fore and aft in the slots to balance the optical tube. The altitude bearings have been positioned at the factory to balance a wide range of eyepiece weights with the occasional help of the altitude clutch knobs. However, if you have mostly heavy eyepieces in your observing kit, you may want to adjust the tube balance to compensate for the tube's resulting nose-heavy balance.
By tilting the optical tube down until it is parallel with the ground, and loosening the altitude clutch knobs, you can observe whether the eyepiece end of the tube rises or falls when you let the tube go with your heaviest eyepiece installed. You can then loosen the balance lock screws on the altitude bearings and slide the altitude bearings back or forth in the slotted plates as needed to balance the optical tube properly. An engraved scale on each plate makes it easy to move both altitude bearings the same amount. Tighten the balance lock screws and your tube is balanced for the majority of your eyepieces. Balancing the tube needs only be done once if you discover that your optical tube is consistently nose- or tail-heavy. The altitude clutch knobs will take care of most occasional minor imbalance situations when changing between eyepieces of different weights.
Altazimuth base (rocker box): The altazimuth base that the optical tube rides in is crafted of strong, lightweight, and water-resistant laminated particle board. The base is shipped disassembled, but can be put together in about a half an hour using only a Philips-head screwdriver and the supplied hardware and hex-head wrench. The GS880 moves in azimuth on dozens of steel roller bearings riding between two metal plates. Push the scope lightly in any direction and it starts moving at the touch of a finger – smoothly and with no fuss. Stop pushing and it settles down immediately, with no shudder or vibration to mar your viewing experience. A carrying handle is provided to make carrying the rocker box easier.
GSO is a leader in optical telescopes and accessories and their products have been sold for years by the "Big Three" (Meade, Celestron and Orion) under their own brand names. GSO telescopes and accessories are also sold under different names world-wide; Zhumell (USA), Apertura (USA), TPO (USA), Teleskop Service (Germany), Sky Optic (France), Antares (Canada), Astronz (New Zealand), and more than a dozen more brands too many to name. GSO is known for their high consistency in quality control, low defect rate, and their Taiwanese-based manufacturing scores closer to Japan in quality than other telescope manufacturers which mostly manfacture thier scopes in Mainland China. Give these telescopes a try - you will not be disappointed!
A very well made and easy to use smart telescope, ideal for someone like me who is new to astro-photography. I found it very easy to connect with my smart phone and was able to take my first solar photo within a few minutes. I am still waiting for some clear skies before trying out the stargazing mode.