It can also be to the side and slightly behind the model, which will create even more dramatic shadows.
Split lighting is easy to create. You simply place your light source on the side of the model. It can also be to the side and slightly behind the model, which will create even more dramatic shadows. This is a great technique to create moody images, but it is less forgiving to skin imperfections. It also works better with a serious expression than a grin.