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While the basic Vixen Great Polaris German equatorial mount is the acknowledged standard by which all mid-priced equatorial mounts are judged, it has a payload capacity of only 15 pounds. This limits its use to small reflector and catadioptric optical tubes and refractors up to 4" in aperture. To expand the high accuracy drive potential of the standard Great Polaris mount, while still retaining its virtues of light weight and simplicity of use, Vixen has produced the upgraded Great Polaris Deluxe 2 mount. Put it on the lightweight but sturdy Vixen #HAL110WT aluminum tripod and you have a good-looking and highly precise equatorial mount for the most demanding visual and astrophotographic applications. - Payload capacity: The Great Polaris Deluxe 2 has 62mm (2.44") diameter steel right ascension and declination axes, for a payload capacity of 22.5 pounds, 50% higher than the standard Great Polaris. This allows the use of heavier optical tubes, plus photoguide scopes and more elaborate equipment for advanced astrophotography.
- Drive system details: To make astrophotography even more precise than the standard Great Polaris, the Deluxe 2 mount has 144-tooth brass main drive gears in both right ascension and declination. To keep to a minimum the periodic error that affects tracking accuracy in astrophotography, the brass right ascension worm gear is precision machined to better than one micron (1/1000th of a millimeter) tolerances for extremely precise tracking of celestial motion. That’s twice the accuracy of the already highly-accurate Great Polaris mount. The declination worm gear has the same 2/1000ths of a millimeter accuracy precision as the right ascension worm gear of the Great Polaris. All right ascension and declination gears are individually inspected before assembly. The end result is a higher unguided tracking accuracy for the Great Polaris Deluxe 2 than is possible with the already outstanding Great Polaris or any lesser mount.
About the standard Great Polaris, a review in Sky & Telescope magazine said, “Adding to the GP’s capability is superb tracking. I measured the tracking error from gear inaccuracies to be approximately 20 arc seconds, and most of that was a gentle drift during 3 minutes of the 10-minute rotation of the worm gear. Mounts costing double the price of the GP do well if they match that figure, let alone beat it." Another review, in The Backyard Astronomer’s Guide, Revised Edition, said simply “The Great Polaris is the best mount for under $1000." And this Great Polaris Deluxe 2 is even better than the standard Great Polaris that these reviewers tested. Optional single and dual axis motor drives are available for no-hands tracking and guided astrophotography. Standard equipment covers for the optional motor drives keep dust and debris out of the motors for more trouble-free operation in dusty environments. The illustration shows the Great Polaris Deluxe 2 mount with an optional dual axis drive system and additional counterweights installed. - Mount weight: The Great Polaris Deluxe 2 has an aluminum die-cast body that’s built to be strong, yet light, to satisfy both stability and ease of portability needs. The complete scope, including standard equipment 8.2 and 4.2 pound counterweights and aluminum tripod, weighs 42.1 pounds, making transportation and setup easy. Additional counterweights are recommended to balance payloads over 13.2 pounds.
- Setting circles and slow motion controls: Standard equipment right ascension and declination setting circles, used to help point the telescope at a celestial object by dialing in its coordinates, are precisely engraved in metal. The right ascension circle is marked in 10 arc minute increments, while the declination circle is marked in two-degree increments. Micrometric manual slow motion control knobs in both axes are supplied for manual tracking and centering of objects. 12.5" flexible slow motion cables are available as an option should a very long focal length optical tube make the standard knobs a little short for convenient use.
- Polar finder and polar alignment: The Great Polaris Deluxe 2 mount is equipped with a 6 x 20mm 8-degree field of view polar finderscope as standard equipment. This finder allows you to align the polar axis of the scope precisely and easily on the north celestial pole, rather than just on Polaris, using the mount’s altitude and azimuth fine adjustment mechanisms. Precise polar alignment allows for drift-free observing and more precise guided astrophotography. The polar finderscope comes standard with a battery-operated variable brightness illuminator and works in both the northern and southern hemispheres. Snap-on covers keep the polar finder protected and dust-free when not in use. Properly utilized, the polar finder will allow the Great Polaris Deluxe 2 mount to be aligned on either celestial pole with three arc minute accuracy. For those situations when Polaris is not visible, hidden behind trees or buildings, a built-in latitude scale and optional compass allow the mount to be roughly aligned on the celestial pole for casual observing. The mount is designed to operate in both northern and southern hemispheres at latitudes from 0° (the equator) to 62° (Central Canada, Northern Europe, and all of South America). Twin adjustment handles allow quick and precise setting of the latitude. Twin adjustment knobs let you fine-tune the azimuth over +/-5°, as well.
- Tripod: The mount’s adjustable-height #HAL110WT 11 pound aluminum tripod is stable and rigid. The tripod legs adjust in length to put the top of the tripod between 25.25" and 38.75" above ground level, to allow the observer to place the focuser at a convenient observing height for most optical tube lengths or optical tube types. Should the tripod legs not have enough extension, however, an optional half pillar is available to fit between mount head and tripod to raise the telescope an additional 9 inches. An optional accessory tray is available to keep eyepieces and other accessories close to hand and out of the dew-laden grass. A built-in bubble level in the mount allows the mount to be quickly leveled for more accurate tracking by adjusting the length of the tripod legs independently.
- Optical tube mounting method: The mount is equipped with a dovetail groove for installing telescope optical tubes. No dovetail plate is supplied to hold the optical tube, as the choice of dovetail plates is dependent on the optical tube to be installed. A variety of optional dovetail plates are available. Setup and takedown times are exceptionally fast, as a single large hand-tighten knob holds the optical tube and dovetail plate in place and adjusts the balance.
If precision and portability are what you’re looking for in a mount for astrophotography, and a prudent price is important, you should take a careful look at the Vixen Great Polaris Deluxe 2 mount on the #HAL110WT aluminum tripod. It is one mid-priced mount well worth considering.
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Astronomics / Christophers, Ltd. 680 S.W. 24th Ave. Norman, OK, 73069
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