I have had great results with Pixinsight using images taken through my telescopes. I recently took 25 3 minute exposures with my Nikon D5500 through a 200mm lens of M31. All the individual images look fine except for the stars having a very small cone shaped flare which I believe to be caused by the lens rather than tracking errors. I used Batch Preprocessing with the default registration settings and the result displayed comma shaped trails around all the stars, as if the dithering had not been handled. Just to make sure I hadn't accidentally messed up a setting I had previously used I reran some old images and the result looked fine. Is there a registration setting I need to adjust?