Celestron Advanced VX 700 Maksutov Cassegrain Telescope Advanced VX - Page 17

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 when slewing from object to object. Just like with Direction Buttons, setting GoTo Approach to positive will make the telescope approach an object from the same direction as tracking (west) for azimuth and counterclockwise in declination. Declination GoTo approach will only apply while the telescope tube is on one side of the meridian. Once the tube passes over to the other side of the meridian, the GoTo approach will need to be reversed. 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. Hint: In order to minimize the affect of gear backlash on pointing accuracy, the settings for Button Direction should ideally match the settings for GoTo Approach. By default, using the up and right direction buttons to center alignment stars will automatically eliminate much of the backlash in the gears. If you change the GoTo approach of your telescope, it is not necessary to change the Button Direction as well. Simply take notice of the direction the telescope moves when completing its final GoTo approach. If the telescope approaches its alignment star from the west (negative azimuth) and clockwise (negative altitude) then make sure that the buttons used to center the alignment stars also move the telescope in the same directions. 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 astroimaging. OTA Orientation - Some users may wish to use an optional tandem bar adapter which allows you to attach two optical tubes to the mount at the same time. When most tandem bars are attached to a mount, the optical tubes are positioned at a 90° angle from the standard configuration. In order for the mount to be successfully aligned with the stars, it must know that a tandem bar is being used and in which direction the optical tube(s) are positioned (East or West) when beginning an alignment. The tandem option must be set before beginning any of the initial star alignments. To set this option, go to the Scope Setup menu, select the Tandem option and press ENTER. Then select from one of the following options: • East - If the attached optical tubes are facing towards the east when the declination index makers are align, select East. • West - If the attached optical tubes are facing towards the west when the declination index makers are align, select West. • Normal - If the tandem bar is no longer being used, select "normal" to turn off this feature. Meridian - This feature instructs the mount on how to respond when it is slewing to objects that are accessible from both sides of the meridian. The meridian feature allows the telescope tube to remain on a desired side of the mount when slewing, and continue to track according to the R.A. slew limits the user has set. See R.A. Limits below. The meridian feature allows for four choices: • Favor Current - Allows the mount to favor whatever side of the mount that it is currently on when slewing to objects close to the meridian. For example, if your R.A. slew limits are set to allow the mount to track 10° past the meridian, then the telescope will continue to stay on its current side of the meridian when slewing to objects that are as far as 10° beyond your Meridian. • Favor West - If the target object is accessible from both sides of the mount, selecting "Favor West" instructs the mount to point to the object as if it were on the west side of the meridian. The optical tube will then be positioned on the east side of the mount and pointing west. • Favor East - If the target object is accessible from both sides of the mount, selecting "Favor East" instructs the mount to point to the object as if it were on the east side of the meridian. The optical tube will then be positioned on the west side of the mount and pointing east. • Disable - This is the default setting, which instructs the mount to always swing around to the other side of the pier as required to view objects on the opposite side of the meridian. However, once at the desired object, the mount will continue to track past the meridian according to the R.A. slew limits that have been set. Mount Settings - Once the mount settings have been calibrated (see Utilities section below) the values are stored and displayed in the hand control. It is not recommended that the calibration values be changed. However, each setting can be changed if necessary to improve the performance of the telescope. • Cone Value - This is the cone error value set when Utilities/Calibrate Mount/DEC Switch - Cone is carried out. • DEC Index - This is the declination index error value that is stored when calibration stars are added after your initial star alignment. • R.A. Index - This is the R.A. index error value set when Utilities/Calibrate Mount/R.A. Switch is carried out. R.A. Limits - Sets the limits that the telescope can slew or track in Right Ascension (R.A.) before stopping. The slew limits are represented in degrees and by default set to 0°, being the position of the telescope when the counterweight bar is extended out horizontally. However, the slew limits can be customized depending on your needs. For example, if you are using CCD imaging equipment that has cables that are not long enough to move with the telescope as it slews across the sky, you can adjust the slew limit on the side of the mount that is restricted by the cables, and command the mount the stop slewing before it reaches this point. Or if you are taking an image of an object that has just crossed the meridian, you can set the limit to allow the mount to continue ENGLISH I 17