Celestron C80ED-R, C100ED-R manual Focusing, Aligning the Finderscope, Calculating Magnification

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Focusing

To focus your telescope, simply turn the focus knob located directly below the focuser. Turning the knob clockwise allows you to focus on an object that is farther than the one you are currently observing. Turning the knob counterclockwise from you allows you to focus on an object closer than the one you are currently observing.

•If you wear corrective lenses (specifically glasses), you may want to remove them when observing with an eyepiece attached to the telescope. However, when using a camera you should always wear corrective lenses to ensure the sharpest possible focus. If you have astigmatism, corrective lenses must be worn at all times.

Aligning the Finderscope

Accurate alignment of the finder makes it easy to find objects with the telescope, especially celestial objects. To make aligning the finder as easy as possible, this procedure should be done in the daytime when it is easy to find and identify objects. The finderscope has a spring-loaded adjustment screw that puts pressure on the finderscope while the remaining screws are used to adjust the finder horizontally and vertically. To align the finder:

1Choose a target that is in excess of one mile away. This eliminates any possible parallax effect between the telescope and finder.

2Release the R.A. and DEC clamps and point the telescope at your target.

3Center your target in the main optics of the telescope. You may have to move the telescope slightly to center it.

4Adjust the screw on the finder bracket that is on the right (when looking through the finder) until the cross hairs are centered horizontally on the target seen through the telescope.

5Adjust the screw on the top of the finder bracket until the cross hairs are centered vertically on the target seen through the telescope.

Image orientation through the finder is inverted (i.e., upside down and backwards left-to-right). This is normal for any finder that is used straight-through. Because of this, it may take a few minutes to familiarize yourself with the directional change each screw makes on the finder.

Calculating Magnification

You can change the power of your telescope just by changing the eyepiece (ocular). To determine the magnification of your telescope, simply divide the focal length of the telescope by the focal length of the eyepiece used. In equation format, the formula looks like this:

Focal Length of Telescope (mm)

Magnification = ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯

Focal Length of Eyepiece (mm)

For example, to determine the magnification of the 80ED with a 20mm eyepiece, divide the focal length of the spotting scope (600mm) by the focal length of the eyepiece (20mm). 600 divided by 20 yields 30 power.

Although the power is variable, each instrument has a limit to the highest useful magnification. The general rule is that 60 power can be used for every inch of aperture. For example, in a 3.2” diameter telescope, such as the 80ED, the maximum useful magnification is 192 power. This is derived from multiplying 60 times 3.2”. Although this is the maximum useful

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Contents Advanced Series Advanced Series GT Introduction Care and Cleaning of the Optics Page Advanced GT Series Setting up the Tripod Attaching the Equatorial MountInstalling the Counterweight Bar Attaching the Center Leg BraceInstalling the Counterweight Attaching the Hand Control Holder Advanced GT Models OnlyFor Non-GT Models Only Attaching the Telescope Tube to the Mount Installing the Finderscope Optical TubeInstalling the Eyepieces Balancing the Tube in R.AAdjusting the Mount Balancing the Telescope in DECAdjusting the Mount in Altitude Adjusting the Mount in AzimuthAttaching the Declination Cable For GT Models Only Powering the Telescope Advanced GT Hand Control Hand Control Operation Double StarsAlignment Procedures Startup ProcedureAuto Align Auto Three-Star AlignQuick-Align Last AlignmentRe-Alignment Slewing to an Object Object CatalogSelecting an Object Finding PlanetsDirection Buttons Tour ModeConstellation Tour Rate ButtonSetup Procedures Identify Scope Setup Features Precise GoToObserving Tip Helpful Hint Utility Features Helpful Hint Advanced GT Image Orientation Focusing Aligning the FinderscopeCalculating Magnification Determining Field of View General Observing HintsCelestial Coordinate System Motion of the Stars Pointing at Polaris Finding the North Celestial Pole DefinitionDeclination Drift Method of Polar Alignment Observing the Planets Observing the MoonLunar Observing Hints Observing the SunSeeing Conditions Solar Observing HintsObserving Deep Sky Objects TransparencyPage Piggyback Short Exposure Prime Focus Photography Terrestrial Photography MeteringReducing Vibration Auto Guiding Care and Cleaning of the Optics Page Page Appendix a Technical Specifications Appendix B Glossary of Terms Page Eclipsing or obscuring the brightness of the star Appendix C Longitudes Latitudes Georgia Minnesota Rhode Island Canada Appendix D RS-232 Connection Additional RS232 Commands Appendix E Maps of Time Zones Page Page Page Page Page Page Page Celestron TWO Year Warranty

C100ED-R, C80ED-R specifications

Celestron, a renowned name in the field of astronomy, has built a reputation for producing high-quality telescopes that are accessible to both amateur and professional astronomers alike. Among their impressive lineup are the Celestron C100ED-R and C80ED-R telescopes, both of which are crafted to enhance the observational experience through advanced optics and user-friendly features.

The Celestron C100ED-R, a 100mm refractor telescope, stands out for its premium extra-low dispersion (ED) glass, which delivers exceptional color correction and sharpness. This ED technology minimizes chromatic aberration, ensuring clearer and more colorful celestial images. The telescope boasts a focal length of 900mm, resulting in a focal ratio of f/9. This combination allows for high magnification capabilities while maintaining a wide field of view, perfect for observing both planetary details and deep-sky objects. The robust, yet lightweight design of the C100ED-R makes it highly portable, allowing for convenient stargazing sessions.

On the other hand, the C80ED-R is a 80mm refractor telescope that combines portability with performance. With its 600mm focal length and f/7.5 focal ratio, the C80ED-R is ideal for wide-field observations, making it easy to explore star clusters and large nebulae. Like its larger counterpart, the C80ED-R features ED glass, which prevents color distortion, allowing for clear and crisp images. The compact design is perfect for those who wish to travel or set up in tight spaces, ensuring that astronomy remains accessible.

Both telescopes are equipped with high-quality multi-coated optics that enhance light transmission, resulting in brighter images. Celestron's user-friendly mounting systems allow for smooth tracking of celestial objects, making it easier to follow objects as they move across the night sky. Additionally, these telescopes come with a variety of accessories, including premium eyepieces that enhance the viewing experience, and sturdy tripods that provide stable support during observations.

In summary, both the Celestron C100ED-R and C80ED-R offer exceptional features that cater to a variety of observing needs. With advanced ED optics, high-quality construction, and portability, they are ideal choices for aspiring astronomers looking to explore the wonders of the universe. Whether you're interested in planetary observation or deep-sky exploration, Celestron's C100ED-R and C80ED-R will not disappoint.
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