>>3768868I would set the lens to at least f/4 to give the stranger more DoF. Then I would get the stranger to stand with my group while I find the framing and focus.
While this is happening, this more socially adept and better looking stranger would introduce himself to the group and start making friends immediately. Something that took many months for me and is still on the verge of collapse.
Then I would mark out where I was standing and ask the stranger to stand exactly there, not to lean backwards or forwards and to hold the camera steady. Then after the shot is taken, I would take a look and see that he missed focus slightly. I'd ask him to try again and tell my group to assume positions for the second time. This would happen a couple more times until either the stranger gets lucky and catches us in focus, or my group get tired of my autistic antics and leave with the stranger, casting me out of my one and only social circle.
Such is the life of a MFcel.