I had some trouble getting DSS to stack this. Using comet stacking, the background came out all mottled. So I took the stacked comet image and layered it on top of the stacked star image that has a good background. I think the comet was about mag 9.5 at the time. Happy to get a bit of a tail.
Nice one Paul, I sometimes have the same problem with DSS. Found if I use subs that don't have the stars overlapping, with a space in between them, it tends to work better.
I did read something about that. It would stack, but I was left with a mottling that appeared to be in the places the stars were. It followed the direction of the comet. It's in the original stack when you stretch it, but not in any of the RAWs.
It really depends where the comet is in the solar system with respect to the Earth and Sun. You may need anything from a wide angle lens to a 20+ inch scope. Generally, fast focal ratios and short exposures seem to work best.