Opening walnuts

Here is a portrait of my father that I did recently. Is it turning 40 a few months ago that made me do this drawing or is it the concentration on his face when he opens walnuts that is so familiar? Or maybe it is that I have been eating hundreds of walnuts from our backyard myself over the last three weeks… I also love the lights and shadows light on his face and the contrast brought by this late morning light.

Please let me know what you think in the comments below…