While this is a nice picture. I do not think it is a portrait. The people in the background take away from the subject. if you have pulled crop from the top left until you cut just a little off the back of your Grandfather, I think that would have made for a more dramatic image. I would also, reduce the shadows and increase exposure. It seems to be about a stop of exposure underexposed.

I LOVE his expression I wish that was the focus of the images.