if shooting night photography, u need a combination of stabilizer + ISO in order to use handheld shots. Im sure you already understand why ur pictures are blur. No choice, u hv to use tripod.
This is one reason why I advise people to get stabilizer in camera sensor instead of in lens. With sensor stabilizer, you will hv IS with wide angel lenses...
canon and nikon don wanna release IS on wide angle lenses, making them at a disadvantage over Pentax and Sony users.
0.6 secs shutter speed on a wide angel lens, with image stabilizer actually can don use tripod. Assuming using 16mm, then with 3 fstop compensation from IS, it allows a shutter speed of 1/2s to be used.