You can do wonders with 30 second sub-exposures.
Here's one of my very first efforts from Lostock in 2006, using a 50mm lens.
The Pointers in Centaurus and the Southern Cross (Crux)
Noisy -- yes. Acceptable -- I think so.
Once my equipment is all set up, I hope to do this region wonders.
Regards,
Humayun