Dear all, I would like to know whether there is some way to feed the guider with a know image rotation angle. I know the first step for guiding is to calibrate the guider camera and as result it computes that field angle, however during our observations our CCD-instrument (spectrograph) has a rotator that usually is rotated several times during the night. For this reason, we would like to avoid to calibrate the guider camera every time the rotator is run, and feed it by the user with then well-know rotation angle. Any suggestions to do that ? Thank you very much, Jose-Miguel
