I've been on vacation in Maine for the past two weeks imaging from dark skies. I live in light polluted Florida so it was quite impressive to see dark skies.
Imaged from Lake Anasagunticook in Canton, Maine
Canon T2i
ProOptic 8mm fish eye lens (f/3.5)
30 second exposure
August 4, 2013 Higher resolution image can be found here
A tip - fisheyes will give a straight horizon at one point (and one point only). Its when they are level and pointing horizontally to their target.
Fisheye plugins that I have tried do not correct that well.
Try that and see if you like it.
I am not 100% sure if that datum is true with the camera in portrait orientation but it may well be, which would mean level the camera in portrait and do your panorama/mosaic that way. Don't angle up the camera use the widefield of the fisheye.
