In this tutorial, I demonstrate using the Area lights in Maya and Arnold renderer, along with adjustment layers and blending modes in Adobe Photoshop, to set up a Rembrandt lighting on a 3d scanned model. It is one of the most popular types of lighting in studio portrait photography and cinematography and works on different face anatomies. You can get final PSD file here and the 3d model of the bearded old man here for further consideration.
The back light (left image), the fill light (middle image), and the key light (right image) separately
Some additional area lights to obtain better or more interesting highlights
In the following images, you can see a comparison between the image rendered in Arnold (left one) and the processed one in Photoshop (right one).
In the below video, you can see how three-point lighting works, and it can bring your characters to life in about twenty five minutes. Consider that this video is sped up 3 times faster than normal. Finally, if you have any trouble, feel free to ask, you can leave a comment at the bottom. I will be happy to answer them.