Advice on Mosaics - Tips and tricks [Deep Sky] Acquisition techniques · Itto Ogami · ... · 26 · 664 · 2

Itto Ogami:
How would one correct for gradients in the subs/panes? My current understanding was that I would get all the panels (say 4) and have them stacked and combined in APP. How would i correct the panes and then stack them? do I have to correct all the subs? How do i do gradient correction etc on 4 panes (assuming I'm correcting the pane and not all the subs) for example and then combine the panes? I assume the subs were all stacked together at once without correcting them to form a single image in APP and then I would stretch the mosaic.                                                                                                                                                                                                                                                                                                                                              I know how to correct for gradients etc. in a single pane image which is what ive always done, but then ive already slightly stretched the pane. how do i correct them prior to stacking? I thought the mosaic had to be stacked untouched to work correctly. I hope you understand my question. Thanks so much!!!

My understanding of the process is this:
1. Perform your normal stacking as you would for any image.
2. Perform your background extraction/gradient correction as you would for any image.
3. Perform a linear fit (or the APP equivalent) to get your images to line up in terms of levels.
4. Stitch the frames together to form your overall mosaic image.
5. Process just like any other image.

This is probably oversimplified but it's about all my brain can handle at the moment. I'm going to be inputting my coordinates tonight for my attempt at a mosaic. I'll keep you posted on how it goes. I'm gonna try my hand at a 3x3 of the Markarian Chain.