Main technical features
The Orion 8974 SkyQuest XT8 PLUS is constructed around a parabolic primary mirror with an 8-inch diameter to gather 78 percent more light compared to a smaller 6-inch mirror. The telescope also comes with an impressive 1200mm focal length (f/5.9) XT8 mirror. The mirror gets up to 94 percent greater reflectivity thanks to the mirror coatings that provide enhanced reflectivity.
Use the dual-speed Crayford focuser to fine-tune the focus of the telescope. The Crayford focuser works better than the single-speed model on the XT8 Classic. It comes with a 1.25-inch step-down adapter for use with 2-inch and 1.25-inch eyepieces. Thanks to the Crayford design, focus adjustments are smooth, accurate, and virtually free of backlash and flexure. The 11:1 fine-focus ratio is highly useful as well. With an 11:1 fine-focus ratio, you’ll be able to make precise adjustments for sharp, crisply detailed views. Aside from a Shorty 2X Barlow, you get a big, 2-inch 28mm DeepView eyepiece to complement the two included eyepieces as well. You also get a 1.25″ 10mm Sirius Plossl ocular for 120-power observations. The Dobsonian design delivers point-and-view simplicity.
When you have to observe the sun in dark conditions, the bright white base helps prevent accidents. There’s a highly visible white trim to allow effortless visual in the dark of night. This telescope allows easy transport and storage with its two-part assembly. You also get dust caps, a quick collimation cap, a telescope focuser and tube plus free download of the special edition Starry Night astronomy software.
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In-depth information
Constructed around a parabolic primary mirror mounted on a cast-aluminum support cell that offers sturdiness, this telescope offers a substantial increase in its ability for observing dust lanes on nebulae. It allows you to view some of the more indistinct structures in faint galaxies as well as the cores of distinctive globular star clusters. Get crisp, clear views using the 1200mm focal length (f/5.9) XT8 mirror, especially at medium to high magnifications towards clear skies at night. You can observe various heavenly bodies including Mars, Saturn and Jupiter that you can view in excellent detail. Thanks to the enhanced reflectivity mirror coatings, you can get up to 94 percent reflectivity so there’s an optimal amount of light transmitted to the eyepiece, which ensures delivery of astoundingly clear views.
The Dobsonian design lets you scan the heavens like seasoned astronomers do. You can get peak performance thanks to the fine-tune focus using the dual-speed Crayford focuser. The design does not carry the same complicated use as a telescope that attaches to a mount and equatorial mount. Use different magnification levels using the Shorty 2X Barlow plus the included eyepieces. Enjoy 42X views that only come with pricier models. Closeups can be obtained with the Sirius Plossl ocular. Double the power to 240X view by using the Sirius Plossl eyepiece and the Shorty 2X Barlow together. The Safety Film Solar Filter allows safe observation of sunspots. Adjusting the secondary mirror cell is easy using the thumbscrew-equipped design that enables tool-free, easy alignment or collimation.
Accidents can be avoided in dark conditions thanks to the brilliant white base trim that is easily visible in poor lighting conditions. The eyepiece rack accommodates up to three 1.25-inch eyepieces and one 2-inch eyepiece. When the Orion EZ Finder II reflex sight is used, focusing is easy. The special edition Starry Night astronomy software is also included for optimized use. The telescope breaks down into two pieces for problem-free storage and transport. Its unique metallic blue color is accented by the adjustable tension knobs on the altitude axis so there are no complicated tensioning springs.
Known issues
Some users have noticed that the included instructions are not as clear, with the photos or diagrams not matching what you will actually see with your own eyes. However, the guide is enough to enable easy assembly and setup. Setting some screws should preferably be done with a driver or drill with adjustable torque settings as the supplied screwdriver may be too challenging to use.
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Bibliography:
1) Dobson’s design innovations
2) Why are Dobsonian Telescopes a Favorite?
4) Introduction to the Dobsonian Telescopes