singleOIII.jpg

Took several OII frames last night to add to my Ha. Looking at the results I seem to have a large ring and a dust trail across my OIII images (arrows). They are not visible at all on the Ha (small image) Am I right in assuming that this is light from Alnitak? Am I also correct in thinking that I need to reduce image time but create more files to get rid? This is a single 600 second light frame taken with Atik 16IC on a ED80.