HI all, this is my 3rd version processing this data. I am fairly new to Pixinsight so the processing is pretty basic. My first versions were with Ha, OIII and SII. The result was milky washed out centre so I subsequently left out the SII data. Now its just over 4 hrs each of Ha and OIII. It is definately cropped too tightly (I did this one after midnight last night and couldn't be bothered to deal with the vignetting in processing). Advice will be greatly appreciated.
GSO RC8, AP CCDT67, ASI1600mm Pro, Zwo 7nm Ha and OIII filters.
Astrobin version
here