I still am without a Nikon camera and I don't own an Olympus flash system so shot these with a mix of gear. Using my Nikon SB800's in an optical slave mode and triggering one of them with a Phottix Strato from my Olympus OM-D EM-5 As you can see I am a fan of duct tape, though someday I may buy a four-square. I ended up moving locations and didn't bring sand bags with me to the second location and ruined two umbrellas when my stand blew over.