This was shot with a studio strobe camera right diffused with a 36" octobox. The sun was also camera right, so I used the octobox to fill some of the harsh shadows. This also allowed me to expose for the sky and blast my subjects with a more even light.
I used the pocket wizard Flextt5 with hypersync. This allowed my camera to sync at 1/6400 and keep my F1.8 creating that shallow DOF.