When shooting stars at night, then you need to set the camera so the stars show up in the photo. Often does this mean that the foreground is underexposed and shows as a silhouette. If you want to make you timelapse really beautiful then you can make a picture of you foreground with good exposure first. with the layer feature you will be able to blend in the picture of the foreground (later 2). with the use of a mask you can then select which part is showing layer 1 or layer 2. This way you can easily merge 2 different movies. Additionally (or mandatory) you might want to add an option where you can multiply one picture times the frames of layer 1, so you only need to add 1 picture which will be shown the entire video.
Last edited 10 May 2015