From my earliest photo shoot with the lovely and talented Patrice.

LE: Canon 40D. EF-S 18-200 f/3.5 - 5.6 IS lens. 1/250 f5.6 ISO 200.
My Britek strobe is in a med softbox in the room in front of her. I don't recall the exact setting but given the proximity I am guessing the power was rather low.