Celestron 8i manual Scope Setup Features, Menu

To replace the contents of any of the user defined objects, simply save a new object using one of the existing identification numbers; NexStar will replace the previous user defined object with the current one.

Get RA/DEC - Displays the right ascension and declination 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.

Observing

Tip!

Scope Setup Features
Setup Time-Site- Allows the user to customize the NexStar display by				MENU
changing time and location parameters (such as time zone and daylight savings).				SCOPE SETUP
Anti-backlash– All mechanical gears have a certain amount of backlash or play
					SETUP TIME-SITE
between the gears. This play is evident by how long it takes for a star to move in the
eyepiece when the hand control arrow buttons are pressed (especially when					ANTI-BACKLASH
changing directions). The NexStar's anti-backlash features allows the user to								AZM POSITIVE
compensate for backlash by inputting a value which quickly rewinds	the motors just
enough to reduce the play between gears. The amount of compensation needed								AZM NEGATIVE
depends on the slewing rate selected; the slower the slewing rate the longer it will								ALT POSITIVE
take for the star to appear to move in the eyepiece. Therefore, the	anti-backlash							ALT NEGATIVE
					SLEW LIMITS
compensation will have to be set higher. You will need to experiment with different
values; a value between 20 and 50 is usually best for most visual observing,							SLEW ALT MAX
whereas a higher value may be necessary for photographic guiding.
							SLEW ALT MIN
To set the anti-backlash value, scroll down to the anti-backlash option and press						FILTER LIMITS
ENTER. Enter a value from 0-99 for both azimuth and altitude and press ENTER							ALTMAX IN LIST
after each one to save these values. NexStar will remember these values and use
them each time it is turned on until they are changed.							ALTMIN IN LIST
					DIRECTION BUTTONS
Slew Limits – Sets the limits in altitude that the telescope can slew without					GOTO APPROACH
displaying a warning message. By default the slew limits are set to 0º to 90º and will								AZM APPROACH
only display a warning message if an object is below the horizon.	However, the
								ALT APPROACH
slew limits can be customized depending on your needs. For example, if you have
					AUTOGUIDE RATES
certain photographic accessories attached to your telescope preventing it from
pointing straight-up, you can set the maximum altitude limit to	read 80º, thus							AZM RATE
preventing the telescope from pointing to any objects that are greater than 80º in
								ALT RATE
altitude without warning.
					CORDWRAP
Filter Limits – When an alignment is complete, the NexStar automatically knows
				UTILITIES
which celestial objects are above the horizon. As a result, when scrolling through
the database lists (or selecting the Tour function), the NexStar hand control will					GPS ON/OFF*
display only those objects that are known to be above the horizon when you are
					WEDGE ALIGN
observing. You can customize the object database by selecting altitude limits that
					LIGHT CONTROL
are appropriate for your location and situation. For example, if you are observing
					FACTORY SETTING
from a mountainous location where the horizon is partially obscured, you can set
your minimum altitude limit to read +20º. This will make sure that the hand control								PRESS UNDO
only displays objects that are higher in altitude than 20º. If you manually enter an
								PRESS "0"
object that is below the horizon using the numeric keypad, the hand control will
					VERSION
display a warning message before slewing to the object.
					GET ALT-AZ
If you want to explore the entire object database, set the maximum altitude limit to					GOTO ATL-AZ
					HIBERNATE
90º and the minimum limit to –90º. This will display every object in the database
			* Indicates features that require
lists regardless of whether it is visible in the sky from your location.
		the use of the optional CN16 GPS
Direction Buttons –The direction a star moves in the eyepiece varies							accessory
depending on the accessories being used. This can create confusion when guiding
on a star using an off-axis guider versus a straight through guide scope. To compensate for this, the direction of

21