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Figure 5-1

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Actual image orientation as seen

with the unaided eye

Inverted image, as viewed with

the eyepiece directly in telescope

Reversed from left to right, as

viewed with a Star Diagonal

A telescope is an instrument that collects and focuses light. The nature of the optical design determines how the light is focused.
Some telescopes, known as refractors, use lenses. Other telescopes, known as reflectors, use mirrors. The Schmidt-Cassegrain
optical system (or Schmidt-Cass for short) uses a combination of mirrors and lenses and is referred to as a compound or
catadioptric telescope. This unique design offers large-diameter optics while maintaining very short tube lengths, making them
extremely portable. The Schmidt-Cassegrain system consists of a zero power corrector plate, a spherical primary mirror, and a
secondary mirror. Once light rays enter the optical system, they travel the length of the optical tube three times.

The optics of the NexStar have Starbright coatings - enhanced multi-layer coatings on the primary and secondary mirrors for
increased reflectivity and a fully coated corrector for the finest anti-reflection characteristics.

Inside the optical tube, a black tube extends out from the center hole in the primary mirror. This is the primary baffle tube and it
prevents stray light from passing through to the eyepiece or camera.

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The image orientation changes depending on how the eyepiece is inserted into the telescope. When using the star diagonal, the
image is right-side-up, but reversed from left-to-right (i.e., mirror image). If inserting the eyepiece directly into the visual back
(i.e., without the star diagonal), the image is upside-down and reversed from left-to-right (i.e., inverted). This is normal for the
Schmidt-Cassegrain design.

Figure 5-2

Содержание NexStar 11

Страница 1: ...I IN NS ST TR RU UC CT TI IO ON N M MA AN NU UA AL L...

Страница 2: ...EQ South Alignment 18 NexStar Re Alignment 18 Object Catalog 19 Selecting an Object 19 Slewing to an Object 19 Finding Planets 19 Tour Mode 20 Direction Buttons 20 Rate Button 20 Setup Procedures 20 T...

Страница 3: ...ransparency 35 Sky Illumination 35 Seeing 36 CELESTIAL PHOTOGRAPHY 37 Short Exposure Prime Focus Photography 37 Eyepiece Projection 38 Long Exposure Prime Focus Photography 39 Periodic Error Correctio...

Страница 4: ...y other high performance features The NexStar s deluxe features combine with Celestron s legendary Schmidt Cassegrain optical system to give amateur astronomers the most sophisticated and easy to use...

Страница 5: ...se goes over the positioning pin in the center of the tripod head Rotate the base until the holes line up with the mounting holes on the tripod Thread the three mounting bolts from underneath the trip...

Страница 6: ...list of celestial objects that are currently visible Press INFO to read information about the object displayed Press the DOWN scroll key to display the next object Press ENTER to slew to go to the di...

Страница 7: ...agonal 9 Hand Control 4 Eyepiece 10 Fork Arm 5 Finderscope 11 Carrying Handle 6 Finderscope Adjustment Screw 12 Tripod CONTROL PANEL C Auxiliary Port 2 A PC Interface Port D 12v Output Jack B Auxiliar...

Страница 8: ...nd the tube should be positioned horizontal to the ground S S S S S S S Se e e e e e e et t t t t t t tt t t t t t t ti i i i i i i in n n n n n n ng g g g g g g g U U U U U U U Up p p p p p p p T T T...

Страница 9: ...that you can look directly into the eyepiece on the telescope with a diagonal while seated V V V V V V V Vi i i i i i i ib b b b b b b br r r r r r r ra a a a a a a at t t t t t t ti i i i i i i io o...

Страница 10: ...Star base It can cause damage to the internal motors You are now ready to attach the included visual accessories onto the telescope optical tube A A A A A A A At t t t t t t tt t t t t t t ta a a a a...

Страница 11: ...the star diagonal 1 Turn the thumbscrew on the visual back until its tip no longer extends into i e obstructs the inner diameter of the visual back 2 Slide the chrome portion of the star diagonal int...

Страница 12: ...ell of the telescope on the top left when looking from the back of the tube 2 Remove any tape covering the two holes The tape is there to prevent dust and moisture from entering the optical tube befor...

Страница 13: ...from left to right Because of this it may take a few minutes to familiarize yourself with the directional change each screw has on the finder P P P P P P P Po o o o o o o ow w w w w w w we e e e e e e...

Страница 14: ...play screen that is backlit for comfortable viewing of telescope information and scrolling text 2 Align Instructs the NexStar to use a selected star or object as an alignment position 3 Direction Keys...

Страница 15: ...n n n This section describes the basic hand control procedures needed to operate the NexStar These procedures are grouped into three categories Alignment Setup and Utilities The alignment section deal...

Страница 16: ...y aligned with the telescope tube the alignment star should now be visible inside the field of view of the eyepiece The NexStar will ask that you center the bright alignment star in the center of the...

Страница 17: ...control pressing ENTER after each entry Remember to select West for longitudes in North America and North for latitudes in the North Hemisphere For international cities the correct hemisphere is indic...

Страница 18: ...ccurately for photography Note Once a Quick Align has been done you can use the Re alignment feature see below to improve your telescopes pointing and tracking accuracy To use Quick Align 1 Select Qui...

Страница 19: ...ey and enter 042 Slewing to an Object Once the desired object is displayed on the hand control screen choose from the following options Press the INFO Key This will give you useful information about t...

Страница 20: ...ontrol The LCD will display the current speed rate Press the number on the hand control that corresponds to the desired speed The number will appear in the upper right corner of the LCD display to ind...

Страница 21: ...the user to customize the NexStar display by changing time and location parameters such as time zone and daylight savings Sidereal Time Displays the Sidereal time for your current time and location Th...

Страница 22: ...osition of the telescope Get Alt Az Displays the relative altitude and azimuth for the current position of the telescope Goto R A Dec Allows you to input a specific R A and declination and slew to it...

Страница 23: ...ge For more information on using PEC see the section on Celestial Photography Direction Buttons The direction a star moves in the eyepiece varies depending on the accessories being used This can creat...

Страница 24: ...OTO RA DEC MENU Center A lignment S tar 2 C enter A lignment S tar 1 FIND IN G NO R TH S E A R CH IN G GPS ALIGNM ENT E N TE R TIM E E N TE R D A TE M M D D Y Y C enter A lignment S tar 2 Center A lig...

Страница 25: ...r and a secondary mirror Once light rays enter the optical system they travel the length of the optical tube three times The optics of the NexStar have Starbright coatings enhanced multi layer coating...

Страница 26: ...the focal length of the eyepiece used In equation format the formula looks like this Focal Length of Telescope mm Magnification Focal Length of Eyepiece mm Let s say for example you are using the 40mm...

Страница 27: ...e In most cases you will not be able to achieve a truly sharp image while in some cases you may actually see a double image Never look across or over objects that are producing heat waves This include...

Страница 28: ...emisphere from the southern Like the Earth s equator it bears a reading of zero degrees On Earth this would be latitude However in the sky this is referred to as declination or DEC for short Lines of...

Страница 29: ...gh celestial latitudes are always above the horizon and are said to be circumpolar because they never rise and never set You will never see the stars complete one circle because the sunlight during th...

Страница 30: ...ar to align the optical tube parallel with the fork arms it must first use its internal downstop switch as a reference for leveling the tube Even though the downstop has been installed at the factory...

Страница 31: ...e e e e el l l l l l l le e e e e e e es s s s s s s st t t t t t t ti i i i i i i ia a a a a a a al l l l l l l l P P P P P P P Po o o o o o o ol l l l l l l le e e e e e e e In each hemisphere ther...

Страница 32: ...itude until the latitude indicator points to your latitude This method can be done in daylight thus eliminating the need to fumble around in the dark Although this method does NOT put you directly on...

Страница 33: ...ful to have an illuminated reticle eyepiece to help you recognize any drift For very close alignment a Barlow lens is also recommended since it increases the magnification and reveals any drift faster...

Страница 34: ...gnifications Lunar Observing Hints To increase contrast and bring out detail on the lunar surface use filters A yellow filter works well at improving contrast while a neutral density or polarizing fil...

Страница 35: ...hey appear black and white And because of their low surface brightness they should be observed from a dark sky location Light pollution around large urban areas washes out most nebulae making them dif...

Страница 36: ...bend light differently Light rays from the same object arrive slightly displaced creating an imperfect or smeared image These atmospheric disturbances vary from time to time and place to place The siz...

Страница 37: ...be operational since you will be determining the exposure length manually You also need a cable release with a locking function to hold the shutter open while you do other things Mechanical and air re...

Страница 38: ...film In order to get the image large enough you must attach your camera to the telescope with the eyepiece in place To do so you need two additional accessories a deluxe tele extender 93643 which att...

Страница 39: ...x xp p p p p p p po o o o o o o os s s s s s s su u u u u u u ur r r r r r r re e e e e e e e P P P P P P P Pr r r r r r r ri i i i i i i im m m m m m m me e e e e e e e F F F F F F F Fo o o o o o o o...

Страница 40: ...NexStar needs to know the current position of its worm gear so that it has a reference when playing back the recorded error Next you must guide for at least 8 minutes during which time the system reco...

Страница 41: ...uiding is still mandatory for long exposure deep sky astrophotography The optional Reducer Corrector lens reduces exposure times making the task of guiding a little easier When getting started use fas...

Страница 42: ...uce vibration is with the Vibration Suppression Pads These pads rest between the ground and tripod feet They reduce the vibration amplitude and vibration time C C C C C C C CC C C C C C C CD D D D D D...

Страница 43: ...0 focal length divided by diameter The NexStar 8 has a focal length of 80 inches and a diameter of 8 inches also making it an f 10 optical system When the secondary is removed and the CCD camera is pl...

Страница 44: ...10 Medium size to small galaxies f 6 3 imaging gives you finer resolution then at f 2 but the slower f number will usually require you to guide the image while you are taking longer exposures Guiding...

Страница 45: ...he CCD camera cable to the NexStar and calibrating the autoguider Note that the four outputs are active low with internal pull ups and are capable of sinking 25 mA DC Figure 8 5 M27 The Dumbbell Nebul...

Страница 46: ...rom the telescope tube To minimize the need to clean your telescope replace all lens covers once you have finished using it Since the rear cell is NOT sealed the cover should be placed over the openin...

Страница 47: ...and control buttons to move the de focused star image to the edge of the field of view in the same direction that the central obstruction of the star image is skewed 5 While looking through the eyepie...

Страница 48: ...cope at a 45 angle with images that are oriented properly upright and correct from left to right It is useful for daytime terrestrial viewing Eyepieces Like telescopes eyepieces come in a variety of d...

Страница 49: ...nsmission of certain wavelengths of light specifically those produced by artificial lights This includes mercury and high and low pressure sodium vapor lights In addition they also block unwanted natu...

Страница 50: ...opular astronomy software programs Sky Maps 93722 Celestron Sky Maps are the ideal teaching guide for learning the night sky You wouldn t set off on a road trip without a road map and you don t need t...

Страница 51: ...ear Field of View at 1000 yds 47 5 ft 34 5 ft Optical Tube Length 21 25 Weight of Telescope 42 lbs 65 lbs Weight of Tripod 26 lbs 26 lbs Electronic Specifications Input Voltage Maximum Minimum 12 V DC...

Страница 52: ...asured from due north between the astronomical meridian the vertical line passing through the center of the sky and the north and south points on the horizon and the vertical line containing the celes...

Страница 53: ...the end of its life cycle O Open Cluster One of the groupings of stars that are concentrated along the plane of the Milky Way Most have an asymmetrical appearance and are loosely assembled They contai...

Страница 54: ...ing Moon The period of the moon s cycle between new and full when its illuminated portion is increasing Z Zenith The point on the Celestial Sphere directly above the observer Zodiac The zodiac is the...

Страница 55: ...6 Mather AFB 121 1 8 38 34 2 Mcclellan 121 2 4 38 40 2 Merced 120 31 2 37 16 8 Miramar NAS 117 9 32 52 2 Modesto 120 57 37 37 8 Moffet 122 3 37 25 2 Mojave 118 9 35 3 Montague 122 31 8 41 43 8 Montere...

Страница 56: ...wa 92 27 41 6 Sioux City 96 22 8 42 24 Spencer 95 9 43 10 2 Waterloo Mun 92 2 4 42 33 KANSAS Chanute 95 28 8 37 40 2 Col J Jabar 97 13 2 37 45 Concordia 97 39 39 33 Dodge City 99 58 2 37 46 2 Elkhart...

Страница 57: ...ercury 116 1 2 36 37 2 Nellis AFB 115 1 8 36 13 8 Owyhee 116 10 2 42 34 8 Reno 119 46 8 39 30 Tonopah 117 4 8 38 4 2 Wildhorse 116 15 41 19 8 Winnemucca 117 4 8 40 54 Yucca Flat 116 4 8 37 34 8 NEW HA...

Страница 58: ...101 27 32 18 Brownsville 97 25 8 25 54 Brownwood 98 57 6 31 47 4 Carswell AFB 97 25 8 32 46 8 Chase NAS 97 40 2 28 22 2 Childress 100 16 8 34 25 8 College Stn 96 22 2 30 34 8 Corpus Chrst 97 3 27 46...

Страница 59: ...3 25 e 52 30 n Birmingham England 1 55 w 52 25 n Bombay India 72 48 e 19 0 n Bordeaux France 0 31 w 44 50 n Bremen Germany 8 49 e 53 5 n Brisbane Australia 153 8 e 27 29 s Bristol England 2 35 w 51 28...

Страница 60: ...eful to check communication Goto Azm Alt B12AB 4000 10 characters sent B Command 12AB Azm comma 4000 Alt If command conflicts with slew limits there will be no action Goto Ra Dec R34AB 12CE Scope must...

Страница 61: ...61 APPENDIX E MAPS OF TIME ZONES...

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Страница 69: ...nds of meteors per hour Solar Eclipses in North America plus Total Eclipses Around the World Date Eclipse Type Duration Location 2001 Dec 14 Annular 03m53s North America Hawaii 2001 Jun 21 Total 04m57...

Страница 70: ...rized repair Further product malfunction or deterioration due to normal wear is not covered by this warranty CI DISCLAIMS ANY WARRANTIES EXPRESS OR IMPLIED WHETHER OF MERCHANTABILITY OF FITNESS FOR A...

Страница 71: ...et Torrance CA 90503 Tel 310 328 9560 Fax 310 212 5835 Web site at http www celestron com Copyright 2001 Celestron International All rights reserved Products or instructions may change without notice...

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