Celestron 93518 Manuel d'instructions

The G-8Model #110238" OPTICAL TUBE ASSEMBLYModel #11023-1CG-5 EQ MountModel # 91515INSTRUCTION MANUAL

The G-8 • 7With the tripod set up, you are ready to attach the accessory tray to the tripod.There are three wing bolts that hold the accessory

8 • The G-8The equatorial mount allows you to tilt the telescope’s axis of rotation so thatyou can track the stars as they move across the sky

The G-8 • 9Attaching the R.A. Slow Motion KnobWith the mount securely in place, you are ready to attach some of the acces-sories (the telescop

10 • The G-8Attaching the Declination Slow Motion KnobLike the R.A. slow motion knob, the DEC slow motion knob allows you tomake fine pointing

The G-8 • 11Attaching the Counterweight Bar and CounterweightsThe last item to be mounted before the telescope tube is the counterweight baran

12 • The G-8With the mount fully assembled, you are ready to attach the telescope to themount.• Before you attach the optical tube, fully tigh

The G-8 • 13The G-8 lens cap utilizes a bayonet-type locking mechanism to hold it inplace. To remove the lens cap, hold the cover firmly and r

14 • The G-8The telescope should also be balanced on the declination axis to prevent anysudden motions when the DEC clamp is released. To bal

The G-8 • 15For the purpose of polar alignment, there are two directions in which the mountcan be adjusted; vertically, which is called altitu

16 • The G-8The entire telescope and mount is light enough to pick up and carry outside fora casual observing session. If, however, you want

Table of Contents • iTABLE OF CONTENTS▲▲▲▲▲ INTRODUCTION...

The C8 Optical Tube Assembly • 17THE 8" OPTICAL TUBE ASSEMBLY (#11023-1)The Celestron 8 Optical Tube Assembly (OTA) is simply the telesco

18 • The C8 Optical Tube AssemblySetting Up Your C8 OTAInstalling the FinderThe C8 Optical Tube Assembly attaches to any photographic tripod w

The C8 Optical Tube Assembly • 19Removing the LensCapFigure 3-3Attaching the Finder to the BracketWith the bracket firmly attached to the tele

20 • Telescope BasicsTELESCOPE BASICSOnce your telescope has been fully assembled, you are ready to attach theaccessories and have a look. Th

Telescope Basics • 21The EyepieceThe eyepiece, or ocular, is an optical element that magnifies the imagefocused by the telescope. The eyepiec

22 • Telescope BasicsIt should be noted that the image orientation will change depending on theviewing configuration. When using the star dia

Telescope Basics • 23Each of the Celestron 8 telescopes uses the same focusing mechanism. Theprimary mirror is mounted on a ring which slides

24 • Telescope BasicsThe G-8 and the C8 Optical Tube Assembly come with a 6x30mm finder. Thefinder is designed to help you find objects that

Telescope Basics • 25With the telescope fully assembled and all the accessories attached you areready for your first look. Your first look sh

26 • Telescope BasicsNighttime ObservingLooking at objects in the sky is quite different than looking at objects on Earth.For one, many object

ii • Table of ContentsPolar Alignment ...

Telescope Basics • 27You can change the power of your Celestron G-8 telescope just by changingthe eyepiece (ocular). To determine the magnifi

28 • Telescope BasicsWhen working with any optical instrument, there are a few things to rememberto ensure you get the best possible image.• N

Astronomy Basics • 29ASTRONOMY BASICSThis section deals with observational astronomy in general. It includes infor-mation on the night sky, p

30 • Astronomy BasicsLike the Sun, the stars also appear to move across the sky. This motion iscaused by the Earth’s rotation. For observers

Astronomy Basics • 31Figure 5-3When the telescope’s axis of rotation is parallel to the Earth’s axis, stars viewedthrough the telescope appear

32 • Astronomy BasicsFor each hemisphere, there is a point in the sky around which all the otherstars appear to rotate. These points are call

Astronomy Basics • 33Latitude ScalesThe easiest way to polar align a telescope is with a latitude scale. Unlikeother methods that require you

34 • Astronomy BasicsPointing at PolarisThis method utilizes Polaris as a guidepost to the celestial pole. Since Polarisis less than a degree

Astronomy Basics • 35Declination DriftThis method of polar alignment allows you to get the most accurate alignmenton the celestial pole and is

36 • Astronomy BasicsPolar Alignment FindersThere are two finders specifically designed for polar alignment that can be usedwith the G-8 teles

Introduction • 1INTRODUCTIONWelcome to the Celestron world of amateur astronomy! For more than aquarter of a century, Celestron has provided

Celestial Observing • 37CELESTIAL OBSERVINGWith your telescope set up, you are ready to use it for celestial observing.This section covers vis

38 • Celestial ObservingAlthough overlooked by many amateur astronomers, solar observation is bothrewarding and fun. However, because the Sun

Celestial Observing • 39Deep-sky objects are simply those objects outside the boundaries of our solarsystem. They include star clusters, plan

40 • Celestial ObservingStar HoppingYou can use your setting circles to find these objects (as described earlier inthis manual) or try star ho

Celestial Observing • 41Star hopping may take some getting used to since you can see more starsthrough the finder than you can see with the na

42 • Celestial ObservingViewing conditions affect what you can see through your G-8 telescope duringan observing session. Conditions include

Celestial Observing • 43rium. Once adjusted to the outdoor temperature, don’t touch the telescopetube with your hands. When pointing the tel

44 • Celestial PhotographyCELESTIAL PHOTOGRAPHYAfter looking at the night sky for awhile you may want to try photographing it.Several forms of

Celestial Photography • 45Short exposure prime focus photography is the best way to begin recordingcelestial objects. It is done with the cam

46 • Celestial PhotographyThe exposure times listed here should be used as a starting point. Always makeexposures that are longer and shorter

2 • IntroductionYour G-8 telescope is designed to give you hours of fun and rewarding observa-tions. However, there are a few things to consi

Celestial Photography • 47The easiest way to enter the realm of deep-sky, long exposure astrophotography isvia the piggyback method. Piggybac

48 • Celestial PhotographyThe exposure time depends on the film being used. However, five minutes isusually a good starting point. With slow

Celestial Photography • 49This form of celestial photography is designed for objects with small angular sizes,primarily the planets and indivi

50 • Celestial PhotographyThe exposure times listed here should be used as a starting point. Alwaysmake exposures that are longer and shorter

Celestial Photography • 51solar system which includes star clusters, nebulae, and galaxies. While it mayseem that high magnification is requi

52 • Celestial Photography• Ektar 1000 (color print)• Konica 3200 (color print)• Fujichrome 1600D (color slide)• 3M 1000 (color slide)• T

Celestial Photography • 53Fastar Lens Assembly Option – Using your G-8 telescope at f/1.95with optional PixCel CCD CameraYour G-8 telescope i

54 • Celestial PhotographyFastar Lens AssemblyPixCel 237 CCD CameraDescription ofF-numbersThe following is a brief description of the advantag

Celestial Photography • 55As stated above, the exposure times are much shorter at f/1.95 than at f/6.3 orf/10. The field-of-view is wider, so

56 • Celestial PhotographyPlanetary or Lunar--f/20 is a great way to image the planets and features on the moon. With thePixCel CCD camera an

Introduction • 3Figure 1-1This cross-sectional diagram shows the light path of the Schmidt-Cassegrain optical system. Note that the light ray

Telescope Maintenance • 57TELESCOPE MAINTENANCEWhile the G-8 telescope requires little maintenance, there are a few things toremember that wi

58 • Telescope MaintenanceTo check the collimation of your telescope you will need a light source. Abright star near the zenith is ideal sinc

Optional Accessories • 59OPTIONAL ACCESSORIESThe following is a partial list of optional accessories available for your CelestronG-8.Barlow Le

60 • Optional AccessoriesErect Image Diagonal (#94112-A) - This accessory is an Amici prismarrangement that allows you to look into the telesc

Optional Accessories • 61(#93785-8P). It comes with the bracket, finderscope, illuminator and Polarissetting plate. Another option is the 9x

62 • Optional AccessoriesPiggyback Mount (#93598) - Celestron’s Piggyback Mount is a great acces-sory for all observers interested in deep-sky

Optional Accessories • 63Sky Maps (#93722) - Celestron Sky Maps are the ideal teaching guide forlearning the night sky. You wouldn’t set off

64 • The Messier CatalogTHE MESSIER CATALOGThe Messier Catalog, compiled by Charles Messier, was the first extensive listing of star clusters

The Messier Catalog • 65M# NGC# Const. R.A. DEC Mag Type Proper NameH M S ° ‘M36 NGC 1960 Aur 5 36.3 34 08 6.0 Op. Cl.M37 NGC 2099 Aur 5 52.0

66 • The Messier CatalogM# NGC# Const. R.A. DEC Mag Type Proper NameH M S ° ‘M81 NGC 3031 UMa 9 55.8 69 04 6.8 Sp. Gx. Bodes NebulaM82 NGC 30

4 • The G-8ASSEMBLING YOUR G - 8AT POLARIS CThe G-8 (#11023), is the only version of the C8 that is offered on a Germanequatorial mount. L

List of Bright Stars • 67LIST OF BRIGHT STARSThe following is a list of bright stars that can be used to align the R.A. setting circle. All c

FOR FURTHER READINGThe following is a list of astronomy books that will further enhance your understanding of the night sky. Thebooks are broken down

CELESTRON ONE YEAR WARRANTYA. Celestron International (CI) warrants this telescope to be free from defects in materials and workmanship for one year.

Celestron International2835 Columbia StreetTorrance, CA 90503Tel: 310-328-9560Fax: 310-212-5835Web site: http://www.celestron.comCopyright 1999 Celes

The G-8 • 5 1. Finderscope 12. Counterweight Safety Screw 2. Eyepiece 13. Counterweights 3. Star Diagonal 14. Counterweight Shaft 4. Dovetail

6 • The G-8The tripod comes fully assembled with the metal plate, called the tripod head,that holds the legs together at the top. In addition