The highlights on the left side of he face seem blown out and the shadows on the right side of the face seem to dark. I would try again with a softer or larger light source and just try and make the shadows lighter
I dunno.....I suppose because it's quite a prosaic subject. I mean, one photographs one's father and then one posts the photograph on deviantART. It just seems like quite a prosaic thing to do. But on the other hand it is such a damned good photograph (or pair of photographs - whatever the correct term may be). You have taken a subject that could be quite prosaic and produced something really interesting. I think that's what I really like about it.