User manual CELESTRON NEXSTAR 4 GT

[. . . ] INSTRUCTION MANUAL INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 WARNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ASSEMBLING THE NEXSTAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] The Select Model feature will return the hand control to its original factory settings. Parameters such as backlash compensation values along with slew and filter limits will be reset. However, stored parameters such as user defined objects will remain saved even after the model has been changed. RS-232 - The NexStar has a RS-232 port located on the bottom of the hand control that allows it to communicate with many astronomy computer programs such as The Sky by Software Bisque. Before attempting to create a link with a computer, select the RS-232 option and press Enter. 20 N S eady ex tarR M ENU T R ACK IN G M ODE A L T -A Z EQ NO RTH E Q S O UTH OFF R AT E S ID E R E A L SOLAR LUNAR V IE W T IM E -S IT E S IDE R E AL T IM E FILT E R LIM IT S A L T M A X IN L IS T A L T M IN IN L IS T U T ILIT IE S S E TU P TIM E /S ITE A N TI-B A C K L A S H S L E W L IM ITS D IR E C TIO N B U TTO N S L IG H T C O N TR O L SELECT MODEL R S -2 3 2 U S E R OBJE C T S G O TO S K Y O B J SAVE SKY OBJ E NTE R RA & DE C G O TO LA ND O B J SAVE LAND OBJ G E T ALT -AZ G OT O ALT -AZ G E T R A-D E C G OT O R A-D E C A L IG NM ENT AU T O ALIG N P O IN T T U B E N O R T H & L E V E L CIT Y DAT ABASE Un ited States Ch oose State Ch oose City E n ter Tim e E n ter Date L IST NA M E D S TA R N A M E D O B JE C T A S T E R IS M S TOUR V A R IA B L E S T A R DO UBLE S TA R CALDW ELL M E S S IE R NGC S O LA R S Y S TE M SAO In te rn a tio n a l Ch oose Cou n try Ch oose City CUS T O M S IT E En ter Lon g /Lat E n ter Tim e E n ter Date T W O-S T AR ALIG NM E NT LEVEL TUBE SELECT STAR 1 CENTER STAR 1 SELECT STAR 2 CENTER STAR 2 QU IC K ALIG N P O IN T T U B E N O R T H & L E V E L SELECT LO CAT IO N ENTER T IM E E N T ER DA T E NexStar Menu Tree: The following figure is a menu tree showing the sub-menus associated with the primary command functions 21 A telescope is an instrument that collects and focuses light. The Maksutov-Cassegrain optical system 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 MaksutovCassegrain system consists of a corrector plate, a spherical primary mirror, and a secondary mirror spot. Once light rays enter the optical system, they travel the length of the optical tube three times. Figure 5-1 A cutaway view of the light path of the Maksutov-Cassegrain optical design The optics of the NexStar have enhanced multi-layer coatings on the primary and secondary mirrors for increased reflectivity and a multi 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. Image Orientation The image orientation changes depending on how the eyepiece is inserted into the telescope. The NexStar uses three reflective surfaces to bounce the light to the eyepiece. This produces an image that is right-side-up, but reversed from left-to-right (i. e. , reversed). This is normal for the Maksutov-Cassegrain design. Fig 5-2a - Actual image orientation as seen with the unaided eye Fig 5-2b - Reversed from left to right, as viewed through the eyepiece 22 Focusing The NexStar's focusing mechanism controls the primary mirror which is mounted on a ring that slides back and forth on the primary baffle tube. The focusing knob, which moves the primary mirror, is on the rear cell of the telescope just below the star diagonal and eyepiece. If the knob will not turn, it has reached the end of its travel on the focusing mechanism. Once an image is in focus, turn the knob clockwise to focus on a closer object and counterclockwise for a more distant object. A single turn of the focusing knob moves the primary mirror only slightly. Therefore, it will take many turns (about 25) to go from close focus (approximately 20 feet) to infinity. For astronomical viewing, out of focus star images are very diffuse, making them difficult to see. If you turn the focus knob too quickly, you can go right through focus without seeing the image. To avoid this problem, your first astronomical target should be a bright object (like the Moon or a planet) so that the image is visible even when out of focus. [. . . ] The Proper Return Authorization Number must be obtained from CI in advance of return. Call Celestron at (310) 328-9560 to receive the number to be displayed on the outside of your shipping container. All returns must be accompanied by a written statement setting forth the name, address, and daytime telephone number of the owner, together with a brief description of any claimed defects. Parts or product for which replacement is made shall become the property of CI. [. . . ]