Celestron NexStar 8i manual Utility Features

the drive control keys can be changed. To reverse the button logic of the hand control, press the MENU button and select Direction Buttons from the Utilities menu. Use the Up/Down arrow keys (10) to select either the azimuth (left and right) or altitude (up and down) button direction and press ENTER. Pressing ENTER again will reverse the direction of the hand control buttons from their current state. Direction Buttons will only change the eyepiece rates (rate 1-6) and will not affect the slew rates (rate 7-9).

Goto Approach - Lets the user define the direction that the telescope will approach when slewing to an object. This allows the user the ability to minimize the effects of backlash For example, if your telescope is back heavy from using heavy optical or photographic accessories attached to the back, you would want to set your altitude approach to the negative direction. This would ensure that the telescope always approaches an object from the opposite direction as the load pulling on the scope. Similarly, if using the NexStar polar aligned on a wedge, you would want to set the azimuth approach to the direction that allows the scope to compensate for different load level on the motors and gears when pointing in different parts of the sky.

To change the goto approach direction, simply choose Goto Approach from the Scope Setup menu, select either Altitude or Azimuth approach, choose positive or negative and press Enter.

Autoguide Rate – Allows the user to set an autoguide rate as a percentage of sidereal rate. This is helpful when calibrating your telescope to a CCD autoguider for long exposure photography.

Cordwrap - Cord wrap safeguards against the telescope slewing more than 360º in azimuth and wrapping the power cord or accessory cables around the base of the telescope. This is useful when powering the telescope with an optional AC adapter or any time that cables are plugged into the base of the telescope. When you select “Cordwrap On” from the Scope Setup menu, you will be asked to move your telescope opposite to the no-cross line. The no-cross line is a user definable line that the NexStar will not pass in order to slew to an object; rather it will slew the long way around in order to get to the object. For example, if you want the no-cross line to be towards due north, then you would need to slew the telescope in azimuth until the front of the tube is pointing towards due south. Once in position, press Enter to set the no-cross line. By default, the cord wrap feature is turned on once the telescope is aligned.

Utility Features

Scrolling through the MENU (9) options will also provide access to several advanced utility functions within the NexStar such as; Wedge Align, Hibernate and all the optional GPS accessory functions as well.

GPS On/Off (with optional CN16 GPS Accessory)- Allows you to turn off the optional CN16 GPS module. When aligning the telescope, the NexStar will receive information, such as current time, from the GPS. If you want to use the NexStar database to find the coordinates of a celestial object for a future date you would need to turn the GPS module off in order to manually enter a date and time other than the present.

Wedge Align – The NexStar has two equatorial wedge alignment modes (one for the northern hemisphere and one for the southern) that will help you polar align your telescope when using an optional equatorial wedge. For more information on using Wedge Align, see the Astronomy Basics section of the manual.

Light Control – This feature allows you to turn off both the red key pad light and LCD display for daytime use to conserve power and to help preserve your night vision.

Factory Settings – Returns the NexStar hand control to its original factory setting. Parameters such as backlash compensation values, initial date and time, longitude/latitude along with slew and filter limits will be reset. However, stored parameters such as user defined objects will remain saved even when Factory Settings is selected. The hand control will ask you to press the "0" key before returning to the factory default setting.

Version - Selecting this option will allow you to see the current version number of the hand control and motor control software. The first number displayed is the hand control version, the second number is for the azimuth motor control and the third number displayed is for the altitude motor control. If using the optional GPS accessory, the second line of the LCD will display the current GPS and serial bus version.

Get Alt-Az- Displays the relative altitude and azimuth for the current position of the telescope.

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