Orion Telescopes

More Information  · Supplied Accessories  · Recommended Accessories  · Related Documents  · Images of Some Features Price $899.95 Shipping $114.95 Highest Useful Magnification 300x Visual Limiting Magnitude 14.9 Focal Length 1500mm Focal Ratio f/4.9 Resolution 0.38 arc seconds Aperture 12" Net Weight 82 lbs. Heaviest Single Component 51 lbs. Warranty 1 year

The XT12’s immense light-gathering capacity (2¼ times that of an 8" scope) makes it ideal for capturing faint deep space wonders from a dark sky observing site. Binary stars, open and globular star clusters, faint nebulas and galaxies – all are revealed in exceptional and subtle detail. At the same time, good planetary and lunar images are yours for the looking when the atmosphere is reasonably still and undisturbed, although a neutral density or variable polarizing filter in the eyepiece is essential to cut down the brightness of sun-lit solar system objects.

The Orion SkyQuest XT12 Classic is human powered. You move the scope manually – which is faster, quieter, and much less expensive than a motorized system. With only two major components to assemble (tube and base), and a heaviest single component weight of 51 pounds, the scope can be set up in only a few minutes by a reasonably fit single individual. It can be used in your back yard or at a distant dark sky site (the preferred observing location if you want to get the most out of its faint object observing capabilities). Its good optical quality and very reasonable price for such a big telescope make it an excellent buy for the beginning and advanced astronomer alike.

This Telescope’s Optical System . . .

Newtonian reflector optical tube: 12" (305mm) aperture classical Newtonian optics, 1500mm focal length, f/4.9 focal ratio. The durable 58" long x 14" diameter rolled steel optical tube is finished in gleaming black enamel. It weighs only 51 lbs, making it reasonably easy for one person to transport and assemble in the field. A “navigation knob" at the top of the tube provides a convenient grip and makes it easy for you to aim the scope at different parts of the sky.

Fully coated optics: The 12" parabolic primary mirror is coated with highly reflective aluminum and overcoated with a protective layer of quartz for long life.

Primary mirror cell: Die cast aluminum cell with nine-point mirror floatation system. Open back design for faster cool down times. A battery-operated cooling accelerator fan that mounts on the rear cell is also available as an option. Push-pull locking collimation screw pairs help hold the correct collimation longer.

Diagonal mirror: The 2.75" m.a. diagonal is coated with aluminum and overcoated with a protective layer of quartz for long life. It is mounted in a fully-collimatable mirror holder on a thin four-vane spider for minimum diffraction.

Finderscope: The 9 x 50mm right-angle correct image achromatic crosshair finder has a good 5° field of view. It is mounted in a quick-release collimatable holder. The correct image prism in the finder shows you the sky the way it appears to your eye and on star charts. There’s no confusing mirror image view, such as you see in a conventional right-angle finder. 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.

Focuser: 2" aluminum Crayford type, with removable 1.25" eyepiece holder. The Crayford-style focuser has a smooth backlash-free motion that eliminates image shift, making it easier to achieve the sharpest possible focus.

Two eyepieces: Two multicoated 1.25" Sirius Plössls, 25mm and 10mm, are standard equipment. The 25mm provides 60x, with a 0.86° field of view, almost 75% larger than the full Moon, for expansive deep space views of nebulas, galaxies, and open star clusters. The 10mm provides 150x, with a 0.35° field, for close-ups of the Moon, planets, binary stars, and globular star clusters.

Collimating tool: A pinhole-type collimating cap that fits into the focuser drawtube allows quick alignment of the primary and diagonal mirrors. If more precise alignment is desired, an optional battery-powered LaserMate laser collimator is available. The primary mirror is center-marked for easier collimation.

This Telescope’s Mount . . .

Dobsonian mount: The particle board Dobsonian altazimuth mount base has a triangular ground board (rather than circular) to reduce the weight of the base to 31 pounds. The base has a convenient carry handle and an eyepiece rack that can hold three 1.25" eyepieces and one 2" eyepiece. The base is shipped disassembled and needs to be assembled only once, unless you decide to disassemble it to save space for long-term storage. The assembly process takes about 30 minutes and requires no special tools.

Altitude and azimuth bearings: The altitude bearings rest in ultra-high molecular weight (UHMW) polyethylene pads for smooth vertical motion. The azimuth bearing uses Teflon bearing pads for equally smooth “stiction-free" horizontal motion.

CorrecTension balance system: The dual spring tension system applies the correct level of tension to the altitude bearings to balance the weight of different eyepieces. With the CorrecTension system, you can change eyepieces or add a Barlow lens without having to hold the tube in place in altitude by hand or tediously adjust the telescope’s balance with counterweights as you do with other Dobsonians when the eyepiece weight changes. This is particularly important with this scope, given its ability to use heavy 2" eyepieces.

What can you see though the Orion SkyQuest XT12 Classic? Under dark skies, the Orion Nebula becomes 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. As with any large aperture telescope, the performance of the 12" SkyQuest Classic on faint objects will be markedly improved by a dark sky observing site. Light-polluted city and suburban sites are not recommended as the primary observing site with a 12" scope. Such sites require a nebula (light pollution) filter to take even limited advantage of its immense light-gathering (1900 times greater than the sharpest dark-adapted eye).

While it is in deep space observing of galaxies and nebulas from a dark sky observing site that the 12" Orion SkyQuest XT12 Classic excels, significant planetary and lunar observing is also within its capability. All you need is steady skies and a neutral density eyepiece filter or variable polarizer to cut down the immense brightness of solar system objects seen through this “light bucket." Photography is not possible with this manually-operated Dobsonian telescope. The 12" Orion SkyQuest XT12 Classic is designed for visual observing only – to show you faint deep sky wonders by the hundreds and thousands. It does that marvelously well, and at a surprisingly affordable price for such a large scope (less than 1/5th the cost of a 12" catadioptric, for example).