Celestron 8i manual Polar Alignment with optional Wedge, Wedge Align

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Polar Alignment (with optional Wedge)

Even though the NexStar can precisely track a celestial object while in the Alt-Az position, it is still necessary to align the polar axis of the telescope (the fork arm) to the Earth's axis of rotation in order to do long exposure astro photography. To do an accurate polar alignment, the NexStar requires an optional equatorial wedge between the telescope and a tripod. This allows the telescope's tracking motors to rotate the telescope around the celestial pole, the same way as the stars. Without the equatorial wedge, you would notice the stars in the eyepiece would slowly rotate around the center of the field of view. Although this gradual rotation would go unnoticed when viewing with an eyepiece, it would be very noticeable on film.

Polar alignment is the process by which the telescope's axis of rotation (called the polar axis) is aligned (made parallel) with the Earth's axis of rotation. Once aligned, a telescope with a clock drive will track the stars as they move across the sky. The result is that objects observed through the telescope appear stationary (i.e., they will not drift out of the field of view). If not using the clock drive, all objects in the sky (day or night) will slowly drift out of the field. This motion is caused by the Earth's rotation.

Wedge Align

Using the computerized hand control, the NexStar has two equatorial wedge alignment modes (one for the northern hemisphere and one for the southern) that will help you polar align your telescope. After performing either an EQ AutoAlign or Two-Star Alignment, Wedge Align will slew the telescope to where Polaris should be. By using the tripod and wedge to center Polaris in the eyepiece, the fork arm (polar axis) will then be pointing towards the actual North Celestial Pole. Once Wedge Align is complete, you must re-align your telescope using either the EQ Two-Star or EQ AutoAlign methods. Follow these steps to Wedge Align the NexStar in the Northern Hemisphere:

1.With the telescope set up on an optional equatorial wedge and roughly positioned towards Polaris, align the NexStar using either the EQ AutoAlign or Two-Star Alignment method.

2.Select Wedge Align from the Utilities menu and press Enter.

3.Based on your current alignment, the NexStar will slew to where it thinks Polaris should be. Use the tripod and wedge adjustments to place Polaris in the center of the eyepiece. Do not use the direction buttons to position Polaris. Once Polaris is centered in the eyepiece press ENTER; the polar axis should then be pointed towards the North Celestial Pole.

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Contents Page Hand Control Operation Alignment Procedures Care and Cleaning of the Optics Collimation Page NexStar 8i SE StarPointer Finderscope Eyepiece Diagonal Visual Back Appendix C Longitude Latitude Mounting the Telescope to the Tripod Assembling the NexStarStar Diagonal Powering the NexStarHand Control Star Pointer Finderscope Star Pointer InstallationEyepiece Star Pointer Operation NexStar Computerized Hand Control Double Stars Hand Control OperationAuto Two-Star Align Alignment ProceduresTwo Star Alignment EQ North / EQ South Alignment Object CatalogNexStar Re-Alignment Selecting an ObjectSlewing to an Object Tour ModeFinding Planets Rate Button Setup ProceduresDirection Buttons Page Menu Scope Setup FeaturesUtility Features Helpful Hint NexStar Ready Image Orientation Determining Field of View FocusingCalculating Magnification General Observing Hints Celestial Coordinate System Motion of the Stars Wedge Align Polar Alignment with optional WedgeFinding the North Celestial Pole Observing the Planets Observing the MoonObserving the Sun Lunar Observing HintsSeeing Conditions Observing Deep Sky ObjectsTransparency Sky IlluminationPage Short Exposure Prime Focus Photography Full Eyepiece ProjectionPlanet ISO Moon Mercury Venus Mars Jupiter Saturn Long Exposure Prime Focus PhotographyPage CCD Imaging Terrestrial PhotographyMetering Reducing VibrationCollimation Care and Cleaning of the OpticsCollimated telescope Should appear Symmetrical with Page Adapter, Car Battery #18769 Page Page Appendix a Technical Specifications Page Appendix B Glossary of Terms Trillion km 5.87 X 1 trillion mi Right Ascension RA Appendix C Longitudes Latitudes Georgia Minnesota Rhode Island Canada Communication Protocol Appendix D RS-232 ConnectionAppendix E Maps of Time Zones Page Page Page Page Page Page Page Celestron TWO Year Warranty

8i specifications

The Celestron 8i is a highly regarded telescope that has made a significant impact in the world of amateur astronomy, renowned for its performance, advanced features, and user-friendly design. Part of Celestron's Advanced Series, the 8i model boasts an impressive 8-inch Schmidt-Cassegrain optical system, which combines the advantages of a large aperture with a compact design. This allows enthusiasts to explore celestial objects with greater clarity, providing bright, sharp images of planets, star clusters, and nebulae.

One of the standout features of the Celestron 8i is its Fast Star capability, which allows for rapid imaging of celestial objects. Coupled with its advanced StarBright XLT coatings, this system enhances light transmission and increases contrast, resulting in a more vivid and detailed observation experience. This combination makes it an ideal choice for both novice and experienced astronomers who seek high-quality visuals of deep-sky objects.

The telescope's computer-controlled GoTo mount simplifies the process of locating and tracking celestial objects. With the push of a button, users can easily access a database containing over 40,000 astronomical objects, allowing for an effortless stargazing experience. The Celestron 8i also features an intuitive hand controller that enables users to customize their observations and seamlessly navigate the night sky.

The Celestron 8i is designed for portability, despite its robust optical performance. Weighing in at around 45 pounds, it is relatively easy to transport to different observing locations. The telescope's sturdy construction ensures stability while providing ease of setup, facilitating a hassle-free stargazing experience.

In terms of accessories, the 8i comes equipped with a 25mm eyepiece, offering a moderate magnification that is perfect for a variety of targets. Additionally, users can expand their observing capabilities with optional eyepieces, filters, and focal reducers, catering to both visual and astrophotography pursuits.

Overall, the Celestron 8i stands out as a versatile and powerful telescope that meets the needs of amateur astronomers at various skill levels. With its advanced features, superior optics, and impressive usability, the 8i offers a unique and rewarding experience under the night sky. Whether for planetary observation or deep-sky exploration, the Celestron 8i remains a top choice for astronomy enthusiasts.
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