Celestron CR-150 HD instruction manual Balancing the Telescope in DEC, Completely, The CR-150HD

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Balancing the Telescope in DEC

Balancing the Telescope in DEC

The telescope should also be balanced on the declination axis to prevent any sudden motions when the DEC clamp is released. To balance the telescope in DEC:

1.Release the R.A. clamp and rotate the telescope so that it is on one side of the mount (i.e., as described in the previous section on balancing the telescope in R.A.).

2.Lock the R.A. clamp to hold the telescope in place.

3.Release the DEC clamp and rotate the telescope until the tube is parallel to the ground (see figure 2-10).

4.Release the tube — GRADUALLY — to see which way it rotates around the declination axis. DO NOT LET GO OF THE TELESCOPE TUBE

COMPLETELY!

5.Slightly loosen the balance bracket thumbscrew and slide the telescope either forward or backward until it remains stationary when the DEC clamp is released. Do NOT let go of the telescope tube while the balance bracket thumbscrew is loose.

6.Tighten the thumbscrew firmly to hold the telescope in place.

Like the R.A. balance, these are general balance instructions and will reduce undue stress on the mount. When taking astrophotographs, this balance process should be done for the specific area at which the telescope is pointing.

Figure 2-10

As with R.A., the telescope should be balanced in DEC after all the standard accessories (i.e., star diagonal, eyepiece, etc.) have been attached to the telescope.

The CR-150 HD • 17

Image 17
Contents 6 Refractor Model #21017The CR-150HD Assembling the CG-5Equatorial Mount T A B L E O F C O N T E N T Sii Table of Contents Table of Contents Using the Lens Cap Aperture Stop4 Introduction I N T R O D U C T I O NIntroduction How to Use This Manual AWordofCaution6 Introduction The Refractor Optical SystemThe Mount Unpacking Your CR-150HD A S S E M B L I N G Y O U R C R - 1 5 0 H DThe CR-150HD Tripod Head Setting Up the Tripod Adjusting the Tripod HeightAssembling the CG-5Equatorial Mount 10 The CR-150HD Attaching the Accessory TrayAttaching the Equatorial Mount 12 The CR-150HD Attaching the R.A. Slow Motion KnobAttaching the Declination Slow Motion Knob 14 The CR-150HD 1.Lock the DEC clamp to hold the mount in placeTube Rings Dovetail Bracket Attaching the Telescope to the Mount16 The CR-150HD Balancing the Telescope in R.ACOMPLETELY Balancing the Telescope in DEC18 The CR-150HD Adjusting the Mount in AltitudeAdjusting the Mount in Azimuth Disassembling and Transporting Your CR 150 HD Technical SpecificationsStoring Your CR- 150 HD OPTICAL TUBET E L E S C O P E B A S I C S Attaching the AccessoriesThe Star Diagonal The EyepieceFocuser Tension 1 1/4 AccessoryAdapter Built-inT-Adapter22 Telescope Basics FocusingAttaching the Finder Aligning the Finder YourFirstLook Image OrientationDaytimeObserving NEVER POINT YOUR TELESCOPE AT THE SUN UNLESSNighttime Observing 26 Telescope Basics Calculating MagnificationDetermining Field of View GeneralPhotographyHints Your Celestron telescope can be used for both terrestrial and astronomical photography. Your telescope has a fixed aperture and, as a result, a fixed f/ratio. To properly expose your subjects photographically, you need to set your shutter speed accordingly. Most 35mm single lens reflex SLR cameras offer through-the-lens metering that lets you know if your picture is under or overexposed. This is important for terrestrial photography where exposure times are measured in fractions of a second. In astrophotography, the exposures are much longer, requiring that you use the “B” setting on your camera. The actual exposure time is determined by how long you keep the shutter open. More on this in the section on “Celestial Photography.” 28 Astronomy Basics A S T R O N O M Y B A S I C SThe Celestial Coordi- nate System Astronomy Basics Motion of the StarsEquator Polar AlignmentDefinition 30 Astronomy BasicsFinding the Pole 32 Astronomy Basics Latitude ScalesPointingatPolaris 34 Astronomy Basics DeclinationDriftPolar Alignment Finders Aligning the R.A Setting CircleObserving the Observing the MoonPlanets C E L E S T I A L O B S E R V I N GObserving the Sun Using the Lens Cap Aperture StopSOLAROBSERVINGHINTS Celestial Observing38 Celestial Observing Using the Setting CirclesObserving Deep-SkyObjects StarHopping 40 Celestial Observing Transparency Viewing ConditionsSky Illumination Seeing42 Celestial Observing Celestial Photography C E L E S T I A L P H O T O G R A P H YLunar Phase Short Exposure Prime FocusCrescent QuarterThe exposure times listed here should be used as a starting point. Always make exposures that are longer and shorter than the recommended time. Also, try bracketing your exposures, taking a few photos at each shutter speed. This will ensure that you will get a good photo. If using black and white film, try a yellow filter to reduce the light intensity and to increase contrast 46 Celestial Photography PiggybackEktar 1000 color print Konica 3200 color print 48 Celestial Photography Projection PhotographyTelescope Maintenance Care and Cleaning of the OpticsT E L E S C O P E M A I N T E N A N C E O P T I O N A L A C C E S S O R I E S 50 Optional AccessoriesDual Axis Drive System - #93523 Super Modified Achromatic SMA EyepiecesOptional Accessories Motor Drive System - #93518 52 Optional AccessoriesNGC# THEMESSIERCATALOGConst Type54 The Messier Catalog Const Epoch LIST OF BRIGHT STARSStar Name ConstellationAstronomy Texts FOR FURTHER READINGAtlases General Observational AstronomyCELESTRON ONE YEAR WARRANTY Item #21017-INST Price $10.00 Celestron International 2835 Columbia StreetTorrance, CA Tel Fax