The ‘darker’ side is still bright, as split lighting does not necessarily mean one side must be in complete shadow.
Split lighting is a simple technique where one side of the face is lit, and this light does not hit the other side of the face. This generally splits the face in half by light. In these two examples, you can see one side of the face is brighter than the other. The ‘darker’ side is still bright, as split lighting does not necessarily mean one side must be in complete shadow.