Description: Auto guiders are used to keep the telescope centered on an object over a long period of time.  The primary use of auto guiders in Sequence Generator Pro is for "dithering" between frames in order to give your software a better chance of removing camera defects like hot pixels and bad columns.


Sequence Generator Pro does not have a built in auto guider.  Rather it uses the following 3rd party auto guiding software


  • AstroArt - Website
  • MetaGuid - Website
  • PHD2 (aka Open PHD Guiding) - Website.  PHD2 guiding graph is also available in the PHD Graph Module
  • Practice - This is useful only when performing indoor simulations with the guider as part of your setup
  • Direct Mount Guider: If you don't use an auto guider, this can be useful in order to insert dithering between frames.
  • SkyGuide - Website



Guiding Interface


Where the guiding interface is chosen.



Dithering Options


(Not available on all interfaces)


  • Dither Checkbox: Enables dithering between frames when checked.
  • Every X Frames: Dithers on a set interval rather than every single frame.  The "count" is only reset on new sequences and when sequence reset is used.  For instance if you set this value to "5" and had 2 targets each with 4 frames the first target would not dither, but the second target would dither after the first frame.  The "frame count" is global. 



Settling Options


  • Settle at < X pixels For Y seconds (assuming the "For" checkbox is checked):  Guiding error amount in pixels that much be reached before a new image will be started.  Once guiding is below the pixel amount, it must be maintained for Y seconds in order for the sequence to resume.  This prevents the guiding from settling for a split second and then becoming unsettled.  Settling will be run:
    • After a dithering operation 
    • After guiding resumes from "pause guiding during auto focus"
  • If the "For" checkbox is not checked, the auto-guider will resume (considered "settled") as soon as the guider reports its error as under the user defined pixel tolerance above (even if the very next reading is above the error limit).



Control Options 


(Not available on all interfaces)


  • Pause: Pauses auto guiding
  • Resume: Un-pauses auto guiding
  • Flip Calibration Data: Allows you to manually flip the calibration data of your auto guider.  Generally used after a meridian flip.
  • Stop: Stops auto guiding



Other Options


(Not available on all interfaces)


Pause Directives


  • Pause guiding during auto focus: Pauses auto-guiding when auto focus is running.  Useful if you use an OAG for guiding and running the Auto Focus routine (guide stars will be out of focus for a couple minutes).
  • Pause guiding during image download: Pauses auto-guiding between images.  Useful if your guide camera data connection is "noisy" and causes issues with your imaging camera.  This options is also pretty much mandatory if you are using an on-board SBIG guide chip.  This option currently only works on SBIG cameras.
  • Pause guiding during backlash comp (OAG):  Use this option to puase guiding when your focuser is using backlash compensation.  Backlash compensation can move far enough out that your guide camera's star will essentially disappear and cause PHD2 to send "star lost" messages.  Using this option will help to prevent that.


Stop Directives


  • Stop when sequence completes: stops the auto guider when all events in a sequence have been completed.  
  • Stop when waiting for next target.  In the case where SGPro has finished a target and there is a delay before the next starts, this will fully stop the guider until the next target starts.  This is useful in order to prevent loss of guide star alarms or errors stemming from failure to move a stationary mount.


Other Directives


  • Settle auto guider before auto focus frames:  Check this box if you need to ensure guiding is stable during the autofocus routine (as the guide star changes position and shape).  This is normally reserved for long focal length, OAG and SCT combinations.  Those of you who use an SCT stock focuser (either with the Feathertouch/Microtouch combo, Robofocus or the Rigel Systems motor) have to deal with image shift when the focuser moves. Each time the focuser moves in for the next AF exposure, the guide star is nudged a few arc seconds off center because of SCT image shift. The guider will then pull it back in during each AF exposure - and the mirror also settles back into its "rest position" - but not always at the same speed. So this throws off the HFR calculations.
  • Restart current frame when guider distance > X pixels:  Allows your current frame to be canceled and reattempted if you get a guiding error greater than X pixels.  Note that you can turn this option off at any time, but turning when turning it on, the option will not take effect until the next light frame starts.
  • Recalibrate auto guider when target changes:  This option should seldom be used.  If you use an ASCOM connection from PHD2 to your mount, PHD2 will automatically adjust the current calibration to accommodate for changes in declination.  If, for some reason, you are still using an ST-4 interface for guiding, this option may prove useful if switching targets causes a meridian flip or a large change in declination.


PHD2 Settings


In an effort to become more tightly integrated with the PHD2 auto guider, SGPro implements some settings that are specific to this relationship.  In order to access them, choose "PHD2" as the auto guider from the drop down list, then click the settings button.  If this is the first time you have done this, a warning dialog will appear indicating that SGPro does not know where you have installed PHD2.  To correct this, click the "Browse..." button and find your PHD2 install folder.  Once chosen, you will not need to do so again.  In addition to this, clicking the "Settings" button in the future will actually open PHD2 for you in order to complete the rest of the settings.  The PHD2 settings dialog looks like this (note that you can set this for the current sequence via the control panel or you can set this per equipment profile via the equipment profile manager):



The install path (described above) is a global setting and applies to all sequences and profiles.  The other settings here can be set per equipment profile.  SGPro will query PHD2 for a list of PHD2 profiles you have created.  Here, you can match a PHD2 equipment profile with a particular set of gear (the gear in the corresponding SGPro profile).  


    • Open and connect gear:  Checking this option will, when the sequence starts, open PHD2, connect the guider gear (as you defined in your PHD2 profile) and then start guiding.
    • Disconnect gear:  When the sequence finishes, the guider will be stopped and all gear disconnected.


It is also possible to connect / disconnect your PHD2 gear by clicking the "Connect" or "Disconnect" button.  For convenience, these buttons are also located on the PHD2 docking module.