Using the Lens Cap Aperture Stop | Celestron CR-150 HD specs

▲	CELESTIAL OBSERVING	3 6
	Observing the Moon	36
	Observing the Planets	37
	Using the Lens Cap Aperture Stop	37
	Observing the Sun	37
	Observing Deep-Sky Objects	38
	Using the Setting Circles	38
	Star Hopping	39
	Viewing Conditions	41
	Transparency	41
	Sky Illumination	41
	Seeing	41
▲	CELESTIAL PHOTOGRAPHY	4 3
	Short Exposure Prime Focus	44
	Piggyback	46
	Projection Photography	48
▲	TELESCOPE MAINTENANCE	4 9
	Care and Cleaning of the Optics	49
▲	OPTIONAL ACCESSORIES	5 0
▲	THE MESSIER CATALOG	5 3
▲ LIST OF BRIGHT STARS		5 6
▲	FOR FURTHER READING	5 7

Table of Contents • iii

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Celestron CR-150 HD instruction manual Using the Lens Cap Aperture Stop, Table of Contents

Contents

Model #21017 The CR-150HD6 Refractor T A B L E O F C O N T E N T S ii Table of ContentsAssembling the CG-5Equatorial Mount Table of Contents Using the Lens Cap Aperture Stop 4 Introduction I N T R O D U C T I O N Introduction How to Use This Manual AWordofCaution The Refractor Optical System The Mount6 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 D The CR-150HD Setting Up the Tripod Adjusting the Tripod Height Assembling the CG-5Equatorial MountTripod Head 10 The CR-150HD Attaching the Accessory Tray Attaching the Equatorial Mount 12 The CR-150HD Attaching the R.A. Slow Motion Knob Attaching the Declination Slow Motion Knob 14 The CR-150HD 1.Lock the DEC clamp to hold the mount in place Tube Rings Dovetail Bracket Attaching the Telescope to the Mount 16 The CR-150HD Balancing the Telescope in R.A COMPLETELY Balancing the Telescope in DEC Adjusting the Mount in Altitude Adjusting the Mount in Azimuth18 The CR-150HD OPTICAL TUBE Technical SpecificationsDisassembling and Transporting Your CR 150 HD Storing Your CR- 150 HD The Eyepiece Attaching the AccessoriesT E L E S C O P E B A S I C S The Star Diagonal Built-inT-Adapter 1 1/4 AccessoryFocuser Tension Adapter Focusing Attaching the Finder22 Telescope Basics Aligning the Finder NEVER POINT YOUR TELESCOPE AT THE SUN UNLESS Image OrientationYourFirstLook DaytimeObserving Nighttime Observing Calculating Magnification Determining Field of View26 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.” A S T R O N O M Y B A S I C S The Celestial Coordi- nate System28 Astronomy Basics Astronomy Basics Motion of the Stars 30 Astronomy Basics Polar AlignmentEquator Definition Finding the Pole 32 Astronomy Basics Latitude Scales PointingatPolaris 34 Astronomy Basics DeclinationDrift Polar Alignment Finders Aligning the R.A Setting Circle C E L E S T I A L O B S E R V I N G Observing the MoonObserving the Planets Celestial Observing Using the Lens Cap Aperture StopObserving the Sun SOLAROBSERVINGHINTS Using the Setting Circles Observing Deep-SkyObjects38 Celestial Observing StarHopping 40 Celestial Observing Seeing Viewing ConditionsTransparency Sky Illumination 42 Celestial Observing Celestial Photography C E L E S T I A L P H O T O G R A P H Y Quarter Short Exposure Prime FocusLunar Phase Crescent The 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 Piggyback Ektar 1000 color print Konica 3200 color print 48 Celestial Photography Projection Photography Care and Cleaning of the Optics T E L E S C O P E M A I N T E N A N C ETelescope 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 - #93523 Optional Accessories Motor Drive System - #93518 52 Optional Accessories Type THEMESSIERCATALOGNGC# Const 54 The Messier Catalog Proper Name Constellation LIST OF BRIGHT STARSEpoch Star Name General Observational Astronomy FOR FURTHER READINGAstronomy Texts Atlases CELESTRON ONE YEAR WARRANTY Celestron International 2835 Columbia Street Torrance, CA Tel FaxItem #21017-INST Price $10.00