How do I improve my telescope's GoTo performance?
November 11, 2008
- Make sure your tripod is level and stationary. Use a bubble level to help.
- Enter in coordinates accurately or, better yet, equip the scope with a GPS unit if applicable. For those scopes with a built-in GPS, make sure it’s set correctly to Standard or Daylight Savings Time. Make sure that the GPS has linked before starting the alignment.
- Make sure the telescope is properly balanced in both the Dec and RA axes.
- Ensure that both clutches are tight.
- Check your backlash settings and adjust accordingly. For the CGE and CPC mounts, the object should move within 3 seconds at rate 3. For the NexStar SE, it should be 3 seconds at rate 5.
- In Scope Setup > GoTo Approack, use setting of Alt Negative, Azm Positive. With these settings, the GoTo for an object will be seen moving up and right through an eyepiece and diagonal attached to a SCT.
- Make sure your finder is aligned to the main scope. Use a higher-power eyepiece to perform the Align on each star (a zoom eyepiece is convenient here). You may want to defocus to make the star easier to find.
- Always choose bright alignment stars (brighter than or equal to magnitude 2.5) on opposite sides of the meridian and as far apart as possible. Avoid using planets and especially the moon as alignment objects.
- During alignment, place the star to the lower left-hand quadrant and approach with up and right keys.
- After successful alignment, use the Calibrate GoTo function.
- Precise GoTo enables you to choose an object from a database and use a brighter, different nearby star to align with for enhanced accuracy. Once you have aligned on the nearby star, the hand control calculates the offset between your alignment and its GoTo. It uses this offset when slewing to the chosen object
- Over the course of an observing session, you have the ability to replace alignment stars. This is very useful when looking at objects that have risen in the east during the night. Simply select your object from a list and slew to it. Press Undo until the top level showing the scope name is displayed. Press Align. Select alignment stars using the up-down keys and press Enter. Choose which alignment star you want to replace; usually you will want to choose the one closest to your object to maintain widely spaced alignment stars. Use the finderscope to center the star, press Enter. Finally, use the eyepiece to center the star and press Align.
- Sync will improve pointing accuracy in a specific region of the sky. Like Precise GoTo and replacing an alignment star, first choose an object from one of the database lists and slew to it. Once the slew is complete, press Undo until at the main menu (scope name displayed). Press Align. Use up-down keys and select the Sync option. Press Enter. Center your object in the finderscope, press Enter. Then center your object in the the eyepiece and press Align.