This gentleman agreed to pose for me. He wanted to know whether my camera was digital or film. He said he would pose if it was digital but not if it was film. I am not sure exactly what his reasons were.
He was patient and followed my directions on where to stand. Several photographers have asked me how I get people to pose for me. Rather than repeating myself I'd like to refer you to an article I wrote back in May 2005.
I hope it helps you and as always your comments are gratefully received.