|
Thanks all for your input.
Just to recap and answer some questions:
1. Yes, I use a flattener/reducer. Obviously the distance between the imaging chip and the flattener isn't right, hence the coma at the corners.
2. Yes the individual subs look ok as they are guided images (maybe half a dozen maybe slightly off due to guiding issues).
3. The problem is when the images are stacked and the resultant stack has elongated stars in the central region near the pillars. I am not worried about the corners as they get trimmed off in the final image.
4. I think the problematic images are those done after the meridian flip (when the pillars are upside down). when I stacked the other images before the flip, the stars are sharp in the middle. But if I stack those with the flipped images, the central stars are elongated.
Malcolm managed to stack all the images in PI but I haven't seen the final image to see the central stars.
Anyway, thanks for your comments so far and I will keep you posted re the central star elongation issue.
Bo
|