Being very critical here (as its a good shot but you want feedback anyway) the lighting is good to show and bring out the face texture and show how rugged your dad is but its also not quite correctly balanced as its still just a little to dark on the left hand side. Also the dof is very slightly out, you have the nose, chin, lips and right eye (as we look at the shot) in focus and then it all blurs out nicely, however he has his head very slightly turned and because the dof is shallow and the focus slightly forward, the left eyebrow is not as sharp. The remedy is to have him straight on or use a dof that is a tiny bit larger and make sure it covers the important parts perfectly.
As I said its a great shot, especially with the lighting equipment setup you are using, but I still think there is a small amount of technical improvement to be found
Hope that helps
