I just took 20 lights DSO with my ASI183 (35sec each saved as .fits)). put it through pipp, then tried to stack in DSS I checked the 20 lights then pressed "Register" It whizzed away then message came up "Only 1 frame will be stacked. Check above a threshold."
I clicked the check above threshold button tried all sorts of numbers (1,99,0,25,50) Nothing worked. What's going on? HELP
There were not many stars in the picture, but when it was whizzing away, I saw that DSS had found around 57 stars. Any ideas?