Beautiful shot Roy, do you ride? I really like the way you've used fill flash on this, it's almost perfect, except for the tiny shadow below the horses chin on the right side. It is perfect if that's not a shadow, and I don't mean to sound picky Roy.
You've got the DOF down pat with the macro lens, it's a great way to isolate your friends face and the wood rail below it's neck from the background, the flash brightens up the face nicely. Alan Kearney