Nice attempts James. At the moment it's hard to photograph the central bulge of the Milky Way with the current moon position. Next time I would limit your exposure time to no more than 20 seconds. Your 30 seconds has broken the 600 rule (which tells you the maximum exposure time before star movement becomes to noticeable for any camera/lens combo: 600/ the TRUE focal length of the lens. 18mm times the canon crop factor of 1.6 = 28.8mm. 600/28.8= 20.8 seconds) and lead to noticeably elongated stars. Focus may have also been a fraction out to. Use live view, if you have it, to zoom right in on the brightest star/planet you can find and try and get it as tight as possible.
Hope this helps
Cheers
Greg
