Rotator Questions.... beginners luck?


I physically rotated the camera last night using the Framing and Mosaic wizard setup. The SGP pop up window told me how much I needed to rotate in degrees each time I tried until it was right. It took me four tries before it was the correct angle. All seemed to work perfectly after that and even PHD2 worked without recalibration. I have no idea how I guessed the correct angle after only 4 tries.

My questions are 1. Should I have recalibrated or does PHD2 know when the camera is rotated. 2. Is there an easier/ quicker/more accurate way to physically rotate the camera other than guessing the degrees (someone mentioned a ring or sticky tape that could be purchased that shows degrees ???) . My 3 panel mosaic was very precise, beginners luck or did I actually do everything correctly ??



  1. Are you using a separate guide scope or an OAG? If a separate guide scope then rotating the main camera will have no effect on the guide calibration. Even if you have an OAG rotating will only have an effect if you rotate the OAG.



Hi Chris,

My OAG is part of the SBIG 8300 camera. So , is that considered “rotating the oag” ???

Thank You and Happy Holidays !!



If your guide camera angle rotates relative to the sky then you need to recalibrate PHD2.

There is a 2.5.x accepted feature request to implement an ASCOM rotator device that would allow PHD2 to read the rotation angle from the Manual Rotator and thus allow you to skip the PHD2 recalibration. You may want to add your support to the feature request so that Ken and Jared can take your request into account when they prioritize features.



You are using the SGPro “Manual Rotator”. PHD2 does not know squat about this “rotator” so if you move it, you PHD2 calibration is shot. We have plans to make an ASCOM driver for the manual rotator so that we can avoid this very situation by making the new PS known to PHD2, your calibration will be adjusted as you physically rotate the camera.

There are lots of things you can do to help with this… the first thing though is to know what angle (east of north) a solve reports when you place it in a position “square” to the OTA (cords down or however it is to you). This will produce 0, 90, 180 or 270. Knowing this can make the guessing game a lot easier.

Sounds like the rotation maybe was not severe enough to throw the guiding (or PHD2 re-calibrated for some other reason you may not have been aware of…).


Thank You. Looks like Ken and Jared are working on the ascom driver for the manual rotator.


Thanks Ken. Appreciate the help.


That is to say “it is on the to-do list… not in-progress”.