Meridian flip shot different

Hi everyone, I have a problem with the meridian flip.
After the meridian jump, the shot is about 5 degrees different, it seems rotated. I use Eqmod and an eq6-r. For plate solving I use ASTAP.
What is the problem in your opinion?
Thank you


After a meridian flip, the camera sees the sky as rotated 180 degrees, if you are not using a rotator to flip the camera.

If you don’t use plate solve / centering after a meridian flip, the scope will not, typically, be exactly centered on the same coordinates as before the flip.


Yes, of course the image rotated 180 degrees ok, but instead I find it as in the image below and I can’t understand why. Although plate solving re-centers the before and after photos there is this difference. He never did that. Do you see in this photo what rotation is there?

It would have been helpful if this image had been included with the original post. This is certainly unusual. I wonder if the camera could be loose and moving during the meridian flip?


This will happen if you have bad cone error. The rotation gets worse the closer you are to the poles but is very minimal around the equator. The rotation also means the diffraction spikes won’t line up.
Use the program conesharp (free to download) to check for cone error. If more than a few arcminutes, it’s worth correcting, which is done by adjusting the bolts on the dovetail to counteract the cone error.

No the camera doesn’t move I’m sure

I try to see, I had a little doubt about this thing. But I don’t think I understand what I need to change. Thanks