Celestron 8i manual Short Exposure Prime Focus Photography

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After looking at the night sky for a while you may want to try photographing it. Several forms of celestial photography are possible with your telescope, including short exposure prime focus, eyepiece projection, long exposure deep sky, terrestrial and even CCD imaging. Each of these is discussed in moderate detail with enough information to get you started. Topics include the accessories required and some simple techniques. More information is available in some of the publications listed at the end of this manual.

In addition to the specific accessories required for each type of celestial photography, there is the need for a camera - but not just any camera. The camera does not have to have many of the features offered on today's state-of-the-art equipment. For example, you don't need auto focus capability or mirror lock up. Here are the mandatory features a camera needs for celestial photography. First, a “B” setting which allows for time exposures. This excludes point and shoot cameras and limits the selection to SLR cameras, the most common type of 35mm camera on the market today.

Second, the “B” or manual setting should NOT run off the battery. Many new electronic cameras use the battery to keep the shutter open during time exposures. Once the batteries are drained, usually after a few minutes, the shutter closes, whether you were finished with the exposure or not. Look for a camera that has a manual shutter when operating in the time exposure mode. Olympus, Nikon, Minolta, Pentax, Canon and others have made such camera bodies.

The camera must have interchangeable lenses so you can attach it to the telescope and so you can use a variety of lenses for piggyback photography. If you can't find a new camera, you can purchase a used camera body that is not 100-percent functional. The light meter, for example, does not have to be operational since you will be determining the exposure length manually.

You also need a cable release with a locking function to hold the shutter open while you do other things. Mechanical and air release models are available.

Short Exposure Prime Focus Photography

Short exposure prime focus photography is the best way to begin recording celestial objects. It is done with the camera attached to the telescope without an eyepiece or camera lens in place. To attach your camera you need the Celestron T-Adapter (#93633-A) and a T-Ring for your specific camera (i.e., Minolta, Nikon, Pentax, etc.). The T-Ring replaces the 35mm SLR camera's normal lens. Prime focus photography allows you to capture the majority of the lunar disk or solar disk. To attach your camera to your telescope.

1.Remove all visual accessories.

2.Thread the T-Ring onto the T-Adapter.

3.Mount your camera body onto the T-Ring the same as you would any other lens.

4.Thread the T-Adapter onto the back of the telescope while holding the camera in the desired orientation (either vertical or horizontal).

With your camera attached to the telescope, you are ready for prime focus photography. Start with an easy object like the Moon. Here's how to do it:

1.Load your camera with film that has a moderate-to-fast speed (i.e., ISO rating). Faster films are more desirable when the Moon is a crescent. When the Moon is near full, and at its brightest, slower films are more desirable. Here are some film recommendations:

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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 Assembling the NexStar Mounting the Telescope to the TripodHand Control Powering the NexStarStar Diagonal Eyepiece Star Pointer InstallationStar Pointer Finderscope Star Pointer Operation NexStar Computerized Hand Control Hand Control Operation Double StarsAlignment Procedures Auto Two-Star AlignTwo Star Alignment NexStar Re-Alignment Object CatalogEQ North / EQ South Alignment Selecting an ObjectFinding Planets Tour ModeSlewing to an Object Direction Buttons Setup ProceduresRate Button Page Scope Setup Features MenuUtility Features Helpful Hint NexStar Ready Image Orientation Calculating Magnification FocusingDetermining Field of View General Observing Hints Celestial Coordinate System Motion of the Stars Polar Alignment with optional Wedge Wedge AlignFinding the North Celestial Pole Observing the Sun Observing the MoonObserving the Planets Lunar Observing HintsTransparency Observing Deep Sky ObjectsSeeing Conditions Sky IlluminationPage Short Exposure Prime Focus Photography Eyepiece Projection FullLong Exposure Prime Focus Photography Planet ISO Moon Mercury Venus Mars Jupiter SaturnPage Metering Terrestrial PhotographyCCD Imaging Reducing VibrationCare and Cleaning of the Optics CollimationCollimated 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 Appendix D RS-232 Connection Communication ProtocolAppendix 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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