Celestron CR-150 HD C E L E S T I A L P H O T O G R A P H Y, Celestial Photography

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C E L E S T I A L P H O T O G R A P H Y

After looking at the night sky for awhile you may want to try photographing it. Several forms of celestial photography are possible with your Celestron CR-150 HD telescope. The most common forms of celestial photography, in order of difficulty are: short exposure prime focus, piggyback, and projection photography. 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 photog- raphy. First, a ‘B’ setting which allows for time exposures. This excludes point and shoot cameras and limits the selection to 35mm SLR cameras.

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 have 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 should have interchangeable lenses so you can attach it to the telescope and 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 does not have to be operational since you will be deter- miningtheexposurelengthmanually.

Use a cable release with a locking function to hold the shutter open while you do other things. Mechanical and air releases are available at most camera stores.

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Contents The CR-150HD Model #210176 Refractor ii Table of Contents T A B L E O F C O N T E N T SAssembling the CG-5Equatorial Mount 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 AWordofCautionThe Mount The Refractor Optical System6 Introduction 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 Assembling the CG-5Equatorial Mount Setting Up the Tripod Adjusting the Tripod HeightTripod Head 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 DECAdjusting the Mount in Azimuth Adjusting the Mount in Altitude18 The CR-150HD OPTICAL TUBE Technical SpecificationsDisassembling and Transporting Your CR 150 HD Storing Your CR- 150 HDThe Eyepiece Attaching the AccessoriesT E L E S C O P E B A S I C S The Star DiagonalBuilt-inT-Adapter 1 1/4 AccessoryFocuser Tension AdapterAttaching the Finder Focusing22 Telescope Basics Aligning the Finder NEVER POINT YOUR TELESCOPE AT THE SUN UNLESS Image OrientationYourFirstLook DaytimeObservingNighttime Observing Determining Field of View Calculating Magnification26 Telescope Basics 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.” The Celestial Coordi- nate System A S T R O N O M Y B A S I C S28 Astronomy Basics Astronomy Basics Motion of the Stars30 Astronomy Basics Polar AlignmentEquator DefinitionFinding the Pole 32 Astronomy Basics Latitude ScalesPointingatPolaris 34 Astronomy Basics DeclinationDriftPolar Alignment Finders Aligning the R.A Setting CircleC E L E S T I A L O B S E R V I N G Observing the MoonObserving the PlanetsCelestial Observing Using the Lens Cap Aperture StopObserving the Sun SOLAROBSERVINGHINTSObserving Deep-SkyObjects Using the Setting Circles38 Celestial Observing StarHopping 40 Celestial Observing Seeing Viewing ConditionsTransparency Sky Illumination42 Celestial Observing Celestial Photography C E L E S T I A L P H O T O G R A P H YQuarter Short Exposure Prime FocusLunar Phase CrescentThe 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 PhotographyT E L E S C O P E M A I N T E N A N C E Care and Cleaning of the OpticsTelescope Maintenance Super Modified Achromatic SMA Eyepieces 50 Optional AccessoriesO P T I O N A L A C C E S S O R I E S Dual Axis Drive System - #93523Optional Accessories Motor Drive System - #93518 52 Optional AccessoriesType THEMESSIERCATALOGNGC# Const54 The Messier Catalog Proper Name Constellation LIST OF BRIGHT STARSEpoch Star NameGeneral Observational Astronomy FOR FURTHER READINGAstronomy Texts AtlasesCELESTRON ONE YEAR WARRANTY Torrance, CA Tel Fax Celestron International 2835 Columbia StreetItem #21017-INST Price $10.00