Contents - Index

Flat Settings

Exposure Limits

Set a Minimum exposure limit to prevent any shutter effects from distorting the flats.  Set a Maximum exposure limit such that a bias frame is sufficient to calibrate the flat without having to worry about matching or scaling dark frames.

Tracking (Sky flats only) 

Selecting On will move the mount between flat exposures.  When using the twilight sky as the flat light source, stars may appear.  By moving the mount between exposures, the stars can be eliminated in the master flat by suitable rejection combining techniques such a Sigma Reject.  Selecting Off will turn off tracking.  Any stars that appear will be trailed for the length of the exposure.

Starting Sun Altitude (Sky flats only) 

These settings are the sun altitude at which to begin sky flat exposures for Dusk  and Dawn.  The values shown are good starting points but you may adjust them based on your own experience by reviewing the log.

Solar Null Point (Sky flats only) 

When Auto is checked, the telescope will be slewed to that point in the twilight sky that has a minimum gradient, needed for good flats.  When unchecked, you can enter your own altitude and azimuth for sky flats.


Enter the average bias level, if known, for your camera. This improves exposure convergence to the desired target ADU and is especially important when a dim flat source is used. If the average bias level is not known, then enter 0.

  • CCDAutoPilot has integrated support for this flat panel.  All that is needed is to use the button to point to the AACmd.exe file, usually located at C:\Program Files\Alnitak Astrosystems\Alnitak Astrosystems Controller\ To clear an entry, simply hit Cancel after hitting .