Here's my first dumbell with this setup, can't believe how green this DSO is!
I decided to two minute exposures for this, it seems more than ample. The dark frames I used were five minute exposures, but it cleaned up the images quite nicely.
Telescope 8” f/4 astrograph on a HEQ Pro 5 mount, orion mini guider.
Unmodded Canon 1100D at ISO 800.
16 x 120 sec subs ISO 800,
11 dark frames, 11 flat frames and 11 bias.
Stacked in DSS and post process in Phototshop.
You're getting there.
There are a few different ways you can go about processing this neb. It all depends on what you wish to high light.
Keep experimenting with settings and see what you come up with.
It's great fun isn't it.