My efforts from last night. Tripod mounted Pentax *istDS, ISO 3200 30s. Tamrom 90mm SP f/2.5 @ f/3.5. 19 lights, 5 darks and offset frames stacked in DSS using Standard Mode. Kappa Sigma clipping set and Comet set to "Stars and Comet". Desaturated and rough levels in PS Elements 9. My question is: how do I get rid of the arcs in the background? Any help appreciated. This is not one of my best efforts.