Quote:
Originally Posted by Paul Haese
Thanks all much appreciated.
Marc, I have found when using data sets from different nights that doing the following works. Select the 6 stars then go to FFT and do an align rotate and scale. This gets it really close then go back to star snap and click on align there. It just all snaps together from there. It seems to get rid of the rotational issues.
I agree CCD stack is a great program for doing a lot of tasks that is needed to be done.
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No doubt it will align similarly scaled subs if you only need to translate, rotate or scale but it won't warp anything. As a test I've redone a stack on Eta. I had Ha, Oiii & Sii taken at different dates. The stacking became an issue because my optics are not top quality and I also use an MPCC. Same focus but using different filters gave me subs with stars in different places especialy on the edges of the frame. The stacking worked in the center but the outer edges didn't match. Registar did warp the subs accordingly and everything was back in place. Another one was a 4 panel mosaic with very little overlap on the LMC. Again CCDStack did a half baked job by rotating, translating and scaling. Some of the stars matched, some didn't. All the subs in the mosaic were still rectangular in shape. I did the same in registar. The reference sub I started on was rectangular, the second one was curved and the last one was shaped like a banana and everything matched. Finally you might have seen a post I did a while ago of the HH heavily cropped both in Ha and RGB. I used absolutely every subs I ever did on the HH and threw everything in registar. ED80, 5" Newtonian and even some 2xbarlowed shots. Registar aligned everything flawlessly. I then did the stacking in CCDStack
