I keep coming back to this. How did you come up with this image of your Grandpa? He looks larger than life, there must be a story in here. Oh, and I like it!
I took the reference photo at a recent funeral for my nephew. The church had pretty interesting lighting. In this one, there were at least two light sources and he was standing more near to one light so it was more intense on that side. It was a fun challenge.
He is a very wise man. He's been a father to me my whole life. The painting is now hanging in his living room.