Celestron C100ED-R, C80ED-R manual Observing Tip Helpful Hint

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Fig 3-3 – Azimuth Slew Limits- This figure shows the full range of motion for the R.A. (azimuth) axis

Observing

Tip!

Helpful

Hint!

example, if you are observing from a mountainous location where the horizon is partially obscured, you can set your minimum altitude limit to read +20º. This will make sure that the hand control only displays objects that are higher in altitude than 20º.

If you want to explore the entire object database, set the maximum altitude limit to 90º and the minimum limit to – 90º. This will display every object in the database lists regardless of whether it is visible in the sky from your location.

Direction Buttons –The direction a star appears to move in the eyepiece changes depending on which side of the Meridian the telescope tube is on. This can create confusion especially when guiding on a star when doing astrophotography. To compensate for this, the direction of the drive control keys can be changed. To reverse the button logic of the hand control, press the MENU button and select Direction Buttons from the Utilities menu. Use the Up/Down arrow keys (10) to select either the azimuth (right ascension) or altitude (declination) button direction and press ENTER. Select either positive or negative for both axes and press ENTER to save. Setting the azimuth button direction to positive will move the telescope in the same direction that the telescope tracks (i.e. towards the west). Setting the altitude buttons to positive will move the telescope counterclockwise along the DEC axis.

Goto Approach - lets the user define the direction that the telescope will approach when slewing to an object. This allows the user the ability to minimize the affects of backlash when slewing from object to object. Just like with Direction Buttons, setting GoTo Approach to positive will make the telescope approach an object from the same direction as tracking (west) for azimuth and counterclockwise in declination. Declination Goto approach will only apply while the telescope tube is on one side of the Meridian. Once the tube passes over to the other side of the Meridian, the Goto approach will need to be reversed.

To change the Goto approach direction, simply choose Goto Approach from the Scope Setup menu, select either Altitude or Azimuth approach, choose positive or negative and press ENTER.

In order to minimize the affect of gear backlash on pointing accuracy, the settings for Button Direction should ideally match the settings for GoTo Approach. By default,

using the up and right direction buttons to center alignment stars will automatically eliminate much of the backlash in the gears. If you change the Goto approach of your telescope it is not necessary to change the Button Direction as well. Simply take notice of the direction the telescope moves when completing it final goto approach. If the telescope approaches its alignment star from the west (negative azimuth) and clockwise (negative altitude) then make sure that the buttons used to center the alignment stars also move the telescope in the same directions.

Autoguide Rate – Allows the user to set an autoguide rate as a percentage of sidereal rate. This is helpful when calibrating your telescope to a CCD autoguider for long exposure photography.

Azimuth Limits - Sets the limits that the telescope can slew in azimuth (R.A.) The slew limits are set to 0º to 180º; with zero being the position of the telescope when the counterweight bar is extended out towards the west and 180º being the position when the counterweight bar is extended out toward the east (see Fig 3-3). However, the slew limits can

be customized depending on your needs. For example, if you are using CCD imaging equipment that has cables that are not long enough to move with the telescope as it slews across the sky, you can adjust the azimuth slew limit on the side of the mount that is restricted by the cables. Using the example above, the user could slew the telescope

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Contents Advanced Series Advanced Series GT Introduction Care and Cleaning of the Optics Page Advanced GT Series Attaching the Equatorial Mount Setting up the TripodAttaching the Center Leg Brace Installing the Counterweight BarAttaching the Hand Control Holder Advanced GT Models Only Installing the CounterweightFor Non-GT Models Only Attaching the Telescope Tube to the Mount Optical Tube Installing the FinderscopeBalancing the Tube in R.A Installing the EyepiecesBalancing the Telescope in DEC Adjusting the MountAdjusting the Mount in Azimuth Adjusting the Mount in AltitudeAttaching the Declination Cable For GT Models Only Powering the Telescope Advanced GT Hand Control Double Stars Hand Control OperationStartup Procedure Alignment ProceduresAuto Three-Star Align Auto AlignLast Alignment Quick-AlignRe-Alignment Selecting an Object Object CatalogSlewing to an Object Finding PlanetsConstellation Tour Tour ModeDirection Buttons Rate ButtonSetup Procedures Identify Precise GoTo Scope Setup FeaturesObserving Tip Helpful Hint Utility Features Helpful Hint Advanced GT Image Orientation Aligning the Finderscope FocusingCalculating Magnification General Observing Hints Determining Field of ViewCelestial Coordinate System Motion of the Stars Pointing at Polaris Definition Finding the North Celestial PoleDeclination Drift Method of Polar Alignment Lunar Observing Hints Observing the MoonObserving the Planets Observing the SunObserving Deep Sky Objects Solar Observing HintsSeeing Conditions TransparencyPage Piggyback Short Exposure Prime Focus Photography Metering Terrestrial PhotographyReducing 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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