+/- 180 option

The new option in the “Target Settings” dialog box to optionally not rotate the camera on a meridian flip defaults to “+/- 180”, that is, don’t rotate on flip. It would seem like the default value should be “Always” so that existing target definitions continue to work as before.


Hi Charlie,

The default setting (+/- 180) means the framing process accepts either of the two angles – the angle entered or the angle entered +/- 180 degrees. When the mount pier flips, the camera rotates 180 degrees and the framing routine accepts the angle without further ado. The +/-180 setting gives the same behavior as before the option was added, so it is naturally the default.

Folks with rotators who want to use the same guide star after the meridian flip on a target would select “Always” to have SGP always rotate to the specified angle precisely. “Always” is the new setting, generally only useful for folks with camera rotators imaging in sparse star fields.


All previous implementations of SGPro accept the angle ± 180 so setting this to ± 180 as the default is correct. The one difference is that SGPro would go to the actual angle to start with, then it would accept that position ± 180 as valid for the remainder of the sequence. Now SGPro will find the rotator position closest to that angle or it’s 180 degree counterpart at the start. Either is OK.

We want this to be the default (most people do… it only requires a single set of flats). If you don’t, you will need to change your targets to “Always” by hand.

Good clarification. I mistakenly thought when a rotator was connected, the camera was ALWAYS rotated during a meridian flip to maintain the same sky position angle.