My two panels in
http://www.ram.org/images/space/downloa ... Ha.v0.xisf
http://www.ram.org/images/space/downloa ... Ha.v0.xisf
My best merged mosaic of the above two panels (jpeg), no postprocessing of any kind, just STF-AS->HT as is:
http://www.ram.org/images/space/downloa ... _Ha.v0.jpg
It's not too bad and there's still a bit of pinching but it's not in the main nebula area and since it's a PITA to black out all the problematic areas I've left it alone. The GMM parametres used to create the above were using average, shrink radius of 1, feather radius of 250. I tried a bunch of other options (perhaps over 100) including overlay, all the shrink radii from 0-10 and feather radii ranging from 0 to 250 and I've found these to work best in this case. All others produce more pinched stars whereas this is basically pinch free.
The above image was created using star alignment with splines, with register/union separate, frame adaptation checked, pixelmath max used to clean up the black edges and then dnaLinearFit and then GMM.
There are many ways to create a mosaic. One involves creating a star field and projecting your images onto there and then merging them with GMM and the other involves just star alignment and then combining with GMM. The first approach you'd think would work better but it creates too many pinched stars in my case. The second approach works better and creates fewer pinched stars which can be dealt with. There's still one perhaps two pinched stars in the current image but I could fix it as long as there's not any more preprocessing left to do (it involves blacking out the problematic areas with pixelmath which is a PITA so I'm holding off until I'm sure the
No post processing of any kind yet - just STF->HT. Still some gradients but not too bad I think especially once I darken things a bit.
I guess I always have the top half of the mosaic if I want to produce a cleaner image. Let me know what you think and if you have any suggestions. I'm trying to bring out the faint wisps beyond the main nebula areas which is in
I do have 20 frames of
Worst case, I could just stick to the top half and I'd still have a decent NB image but I really would like to get this mosaic right. I also can put up the xisf files at various stages (for instance just before GMM) if it'll make your life easier, for those who want to work with these images.
Thanks a lot!
--Ram