I've been using a borrowed Fuji Finepix S5500 for a week or two, and it's certainly a step up from my el-cheapo Kodak automatic. Comet was OK in night mode at 3-sec, f2.9, but when I cranked it up to 15-sec, all I got extra for my trouble was a trillion extra hot pixels & star trails, with no gain in comet brightness. Seems the f/ratio cranked up in synch, so I got longer exposure with less aperture - thanks for nothing!
Tried but couldn't independently set aperture - perhaps it's just that I haven't mastered the controls yet. Anyway, I suppose it's all about making the best of what you've got. With the low light shots there is a lot of noise that has to be dealt with, and I found that the Noiseware program (freeware version, limited to jpegs only) gives me satisfactory results, after tweaking in PS. Downloads at:
http://www.imagenomic.com/
I've attached 3 images showing processing of one of my comet shots, taken at 3-sec, f2.9 in Night Mode: the original image; after tweaking in PS; and after applying Noiseware luminance filter.
Have also attached an image of the Pleiades (3-sec at f2.9), probably about the best I'll do with the camera. No tracking, so anything I do above 3-sec begins to trail. Have fun, Robert_T!
Cheers -