The only way is to use shutter priority on your camera and a tripod. You
need a camera capable of doing this and not all camera have this feature.
If your camera does, set it for 1 second, then look at it. Not good enough?
Increase to 2 seconds, etc. until you get the feel of it. With long
exposures, it is best to have your camera on a tripod (or rest it on
something) otherwise you get a blurry picture.
