i used my nikon d7000 with following manual mode
Lense used - 50mm f1.8
Shutter speed - 20 sec
You can use IOS 1600 and decrease the shutter speed. But, the quality will be not that good. So, I recommend people to test the shot with higher IOS and later on use the slow shutter speed to capture the images.
P.S it was taken from the backyard of my home. So, it would be much better from a dark place