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Atlas German Equatorial Mount and Tripod
The same mount as that is provided with the successful Orion Atlas10 Newtonian Reflecting telescope!
Right: the Orion Atlas mount with provided counterweights, and adjustable height field tripod (80,562 bytes).
Overview: The Atlas is a hefty mount which provides a very good balance of payload capacity, portability, convenience features, and price. This German Equatorial Mount is rewarding to use, and is easily broken down for transport by most teens and adults. When mated to a suitable telescope, the German Equatorial Mount provides:
Evolution of Orion Product: Over the recent years the Orion telescope company has developed innovative telescopes and mounts which have come dominate that area of the telescope market that has traditionally served the more demanding beginning to intermediate amateur astronomer. Particularly with the introduction and evolution of the SkyQuest XT6 6" (15cm), SkyQuest XT8 8" (20cm), and SkyQuest XT10 - 10" (25.4cm) Dobsonian reflecting telescopes, Orion became known to provide such good value and performance that most other manufacturers have had to simply give up trying to compete in this area of the market, even though some clones of the Orion product have been misrepresented as the equal of these Orion telescopes. It was because of the good performance of the Orion SkyQuest telescopes, and the customer satisfaction ethic of Orion that Company Seven made the decision that we needed to make the Orion product line available to our customers.
Background: The Earth's Motion The Earth rotates about its axis once full turn over a period of just under a day. This period of 23 hours 56 minutes 04.09053 seconds is called the sidereal period or the period relative to position of the stars overhead. The sidereal period is not exactly equal to one 24 hour day because by the time the Earth has rotated once on its axis, it has also moved along the path of its orbit around the Sun, because of this the Earth has to keep rotating for about another 4 minutes before the Sun seems to be back in the same place in the sky that it was in exactly a day before. As the Earth rotates in space the celestial objects overhead appear to move in an arc across the sky.
Right: Click image if you wish to see an animated movie of the Earth Rotating.
For an observer located in the Northern Hemisphere objects rise in the Eastern horizon, gradually moving in an arc up and right across the sky towards the South, and then continue moving to the right and down towards the Western horizon. This motion can be observed with the naked eye if one carefully observes the limb of the Moon as it rises or sets behind trees or some other fixed object in the distance, the motion though slow is perceptible. A telescope provides magnifications far beyond that of the human eye, as the magnification of a telescope in increased (25X to 50X, 50x to 100X, etc.) then this motion of an object drifting across the sky will appear accelerated. With a very well designed Alt-Azimuth mount such as that provided on the Orion SkyQuest Dobsonian telescopes it is possible for an observer to track objects by manually guiding the telescope at magnifications of 200X or more, and some people are comfortable at magnifications in excess or 300X.
The solution to the limits imposed by the manually guided Alt-Azimuth mount is the Equatorial Mount. There are a number of designs of Equatorial Mount but those which the amateur is most likely to encounter are the Equatorial Fork, and the German Equatorial arrangement. More Computer Controlled Fork Alt Azimuth mounts are coming available too where the mount moves simultaneously in two axes to stay on target.
The Equatorial Mount is designed to gradually turn a telescope in the opposite direction from that which the Earth is rotating, at the same apparent speed as the Celestial objects are moving. The motion is so slow that few people can observe the motion, this rotation is only on the order of one revolution per 24 hours! To track precisely, the Right Ascension Axis of the Mount is adjusted by the user so that the axis is parallel to the rotational axis of the Earth. An equatorial mount will provide acceptable results for visual uses if the mount is aligned to within about one ot two degrees of the Celestial Pole. But as you align the Mount more and more accurately then the need to periodically make minor adjustments to center a target in the eyepiece will become less frequent. A very accurately alignment of the mount to the Celestial Pole is most beneficial for those persons who intend to attempt astrophotography or CCD imaging.
German Mounts are particularly well suited for telescopes of relatively longer physical lengths, or for improved portability with some mid sized telescopes. Incidentally, in Germany the German Equatorial mount is called a "deutsche Montierung" (thanks Georg).
The German mount arrangement has advantages over the fork mounted designs in that:
The telescope will swing from one side of the mount to another as once proceeds to explore the four quadrants of the hemisphere. When using a German Mount with a Newtonian telescope this may at times put the eyepiece at an uncomfortable position however, most Newtonians we offer will come with or have available as options a pair of clamp style Mounting Rings can be loosened so that one may rotate the optical tube to position the Focuser and Eyepiece at more convenient positions.
Made in China: The Atlas German Equatorial Mount was developed in China, refined for Orion by the manufacturer, and then introduced to the US market in 2003. It resembles the "Atlux", a unique and capable mid size portable German Equatorial Mount which was made in Japan by Vixen. The equatorial mounts and other components made in China for beginner to intermediate amateur telescopes have been evolving into more refined products over the more recent years. Formerly, Chinese made mounts were criticized as being shoddy cheap copies of other makers designs, and lacking refinement; years ago "made in Japan" was synonymous with that view up to about the 1960's. In time Japan got its act together and eventually displaced U.S. manufacturers from the economical amateur telescope market (other market areas too). The Japanese became known as masters of taking ideas from elsewhere, adding their own refinements, and then selling them at modest prices. However, as the Japanese lifestyle became better and more costly, so did the cost of their products. And so by the late 1980's, after the dollar devaluation under the Reagan administration some prominent US manufacturers began the move away from Japanese products to third world nations as sources of labor. Countries making these products came to include Taiwan, Korea, and China. For some years Company Seven refused to offer Chinese made amateur telescopes, mounts and accessories since these often lacked the performance, quality control or refinement of the Japanese products they often mimicked. We always knew that in time some Chinese manufacturers would eventually displace some Japanese sources, as Japan had displaced others and in mid 2001 with the introduction by Orion of the StarMax 127 telescope, Company Seven became convinced China had arrived in the serious beginner to intermediate telescope market.
Payload Ratings capacity ratings of telescope mounts vary with quality of construction and component. Since there are no industry wide standards for determining load capacity, the factory rating alone is not a reliable predictor of performance. Factors that will affect suitability include static load, payload length (torque), tracking accuracy, tripod or pier resonance's, etc. What is most important to the user of the product is 1. how rigidly the mount holds the payload, 2. how smoothly it tracks (the periodic error amplitude and smoothness of a gear set and its support bearings), and 3. how the mount drive system overcomes the moment imparted by the load. These variable will vary with weight of the OTA, and the physical length of that load. The weight put onto a mount can also vary depending how the instrument is to be used, for example one telescope used for visual work only may be as much as 50% lighter in weight than another employed for imaging (possibly with guide scopes, cameras, etc.). The useful capacity of the mount may also vary with local winds since even a slight wind on a large "sail" area (such as that of a large reflecting telescope) can dramatically increase the effective load imparted to the mount. So, a small mount operating from within a Dome might perform as well or better than a larger mount outside a sheltered environment.
The Orion Atlas mount is a good value in terms of the payload capacity, provided accessories and electronics. For the money spent little else in its class can rival it for visual use; it can manage Schmidt-Cassegrains as large as the Celestron C-11, refractors as large as a five or six inch Apo. However, if you seek a mount for more advanced applications, or one that can grow with options including "go to" computer control then you may instead buy a telescope optical tube and mate it to a more capable mount such as our Losmandy G-11. Or you may consider the Orion Atlas as your first mount on which to learn your way around the night sky, and later upgrade to a more sophisticated mount.
Atlas Equatorial Mount: the Atlas equatorial mount is a suitable choice for visual use with many of the medium weight 4 inch (10cm) to 6 inch (15cm) aperture refracting telescopes, Catadioptric, and Newtonian telescopes. Its' sound design considering the intended payloads results in almost complete elimination of unwanted vibration and oscillation; the inevitable downfall of many poor telescope mounts. Whereas in many economical telescopes the image seems to bounce around forever after the scope has been touched, this is not the case with the Atlas. This mount incorporates a number of features that make it attractive, these include:
2. Electronic Dual Axis Drive: The mount incorporates clutched motor and worm gear sets on Declination (Decl.) and Right Ascension (R.A.) to facilitate centering the telescope onto a target, and to permit one to electronically guide the mount to keep it on target.
This drive systems features integrated electronic stepper motor drives on both axes and an external pushbutton hand controller offering slewing speeds of 2x, 8x, and 16x sidereal rate. It has a Northern or Southern Hemisphere setting, as well as labeled RA and Dec buttons and RA and Dec reverse switches. The drives are powered by 12 volts DC, either from the included battery pack (requires 8 D-cell batteries, not included) or from an optional external 12-volt field battery.
3. Elevation and Azimuth adjustment to facilitate pole alignment of the mount, manual screw drives are provided. This makes it possible to move the mount head (without moving the tripod) to the left or right, up or down precisely. This makes getting that last, fine pole alignment adjustment easily. And once aligned, these controls have opposing screws that can be brought to bear in order to secure the mount even more rigidly.
4. Setting Circles: engraved with numbers corresponding to the two dimensional "Right Ascension" (R.A.) and "Declination" (Dec.) coordinate systems used by astronomers to navigate the night sky. These help you to learn about the Celestial Coordinate System, and help you to locate objects in the sky by their cataloged coordinates.
5. Pole Alignment finder telescope to facilitate a quick and accurate Pole Alignment.
Astronomers often use a Pole Alignment telescope in a German Mount as an aid to quickly orient the German Equatorial Mount R.A. Axis onto the Celestial North or South Pole. The Orion Atlas Equatorial Mount includes a Pole Finder as a standard accessory. The eyepiece of this small telescope incorporates a reticle pattern that aids Pole alignment of the Mount in both and the Northern and Southern hemispheres. If setting up a telescope in a permanent location, then other techniques can be used to gradually "zero in" a mount onto the Pole to obtain even greater accuracy. However, the Pole Finder is an especially desirable aid to quick alignment for people who are transporting the mount from one location to another. The Atlas Polar Alignment Finder telescope is provided threaded into the mount head R.A. Axis shaft. For transport the Pole Alignment Finder is protected in a well fitted hard plastic thread on cover as it protrudes visibly from the mount head and would otherwise be vulnerable to (at the least) misalignment from impact damage.
Right: Orion Atlas Equatorial Mount R.A. Axis housing showing furnished integral Pole Alignment Finder Telescope. Click on image for enlarged view (161,618 bytes).
6. The Atlas Field Tripod is surprising for its quality, durability, and rigidity. At first glance, it is a less costly clone of a tripod design that has been widely regarded as the best in the amateur telescope industry. Right down to the stainless steel tubing for the legs and the leg extensions.
When spread and locked the Atlas Field Tripod stands 42 inches (107 cm) high. By pulling out the extension section, the Tripod height can be increased up to 61 inches (155 cm). The Tripod when set to minimum height still puts the eyepiece of a 8 inch f6 or 10" reflecting telescope as typically balanced at a height that is about perfect for someone of between 5 foot 6 inch (170 cm) or taller height. The Tripod when set to minimum or extended height places the eyepiece of a 3 or 4 inch refracting telescope as typically balanced at a height that is perfect for most observers comfortably seated or standing.
The Atlas Field Tripod Leg Spreader Bar incorporating a convenient Eyepiece Holder. The Field Tripod Spreader Bar arrangement provides a stress that aids the rigidity of the Tripod, in this way it mimics the industry standard Meade Instruments Field Tripods. The Spreader easily rotates out of the way to permit the three legs to collapse in for storage. But Orion has taken this a step forward by providing holes in the Spreader so that it can hold up to five 1.25 inch and two 2 inch diameter eyepieces or other similar diameter accessories. Furthermore, this tray is held in place by two keyhole shaped screw holes so that customers may easily slide the tray up and out to remove the tray for transport or if desired.
Left: the Atlas Field Tripod Leg Spreader Bar (161,618 bytes).
To keep dew or other contaminants from marring eyepieces stored on this tray Company Seven recommends you keep eyepiece caps in place when these accessories are stored in the accessory holes. And for use in areas of high humidity consider the use of optional dew prevention devices including our highly successful Kendrick heater systems.
And in another example of how this mount has "learned" from other previous releases and made departures from some other's shortcomings, the Hand Knobs used to lock the Leg length have been positioned pointing towards the inside of each leg to prevent the operator from gashing their ankle while walking near the tripod.
The telescope will swing from one side of the mount to another as once proceeds to explore the four quadrants of the hemisphere, this may at times put the eyepiece at an uncomfortable position. However, the paired clamp style Mounting Rings can be loosened so that one may rotate the optical tube to position the Focuser and Eyepiece at more convenient positions.
The motion on both axes is regulated by clutches which can be adjusted to "buttery smooth" letting you guide the telescope with just the lightest touch from one part of the sky to another.
The Atlas Equatorial Mount incorporates three inch diameter Setting Circles. These circles are engraved with numbers corresponding to the two dimensional "Right Ascension" (R.A.) and "Declination" (Dec.) coordinate systems used by astronomers to navigate the night sky. These help you to learn about the Celestial Coordinate System, and help you to locate objects in the sky by their cataloged coordinates. Company Seven also does offer optional electronic Encoder and digital display devices as aids to celestial navigation which can be added to the Atlas however, most of our customer do not buy these add-ons since they enjoy the thrill of discovery as they learn to "Star Hop" from one object in the night sky to another.
Noteworthy features of the Atlas include:
Atlas Mount Highlights
* Specifications are subject to change without notice.
To read more information about the Atlas Equatorial Mount download the Orion illustrated instruction manual from Company Seven's Library.
Or for additional information about the Atlas 10 telescope with the mount feel free to download the Orion illustrated instruction manual from Company Seven's Library.
SUGGESTED ACCESSORIESThese are optional accessories that are not included with the mount that we recommend you consider for your viewing pleasure and long term success: