Celestron CR-150 HD Ektar 1000 color print Konica 3200 color print, Celestial Photography

Page 47

The exposure time depends on the film being used. However, five minutes is usually a good starting point. With slower films, like 100 ISO, you can expose as long as 45 minutes. With faster films, like 1600 ISO, you really shouldn’t expose more than 5 to 10 minutes. When getting started, use fast films to record as much detail in the shortestpossible time. Hereareprovenrecommendations:

•Ektar 1000 (color print)

•Konica 3200 (color print)

•Fujichrome 1600D (color slide)

•3M 1000 (color slide)

•T-Max 3200 (black and white print)

•T-Max 400 (black and white print)

As you perfect your technique, try specialized films, that is films that are designed or specially treated for celestial photography. Here are some popular choices:

•Ektar 125 (color print)

•Fujichrome 100D (color slide)

•Tech Pan, gas hypered (black and white print)

As with all forms of photography, keep accurate records of your work. This information can be used later if you want to reproduce certain results or if you want to submit photos for possible publication.

Once you have mastered piggyback photography with wide angle and normal lenses, try longer focal length lenses. The longer the focal length, the more accurate your guiding must be. You can continue to increase the focal length of the lens until you are ready for prime focus photography with your telescope.

Celestial Photography • 47

Image 47

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 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 Adapter22 Telescope Basics FocusingAttaching the Finder Aligning the Finder NEVER POINT YOUR TELESCOPE AT THE SUN UNLESS Image OrientationYourFirstLook DaytimeObservingNighttime 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 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 SOLAROBSERVINGHINTS38 Celestial Observing Using the Setting CirclesObserving Deep-SkyObjects 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 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 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 Item #21017-INST Price $10.00 Celestron International 2835 Columbia StreetTorrance, CA Tel Fax