This is the only shot of a recent shoot that came half-way close to turning out okay. I tried to overpower the sun with my flashes, but failed miserably. Ambient light masured in at f8 and 1/180 at ISO 200. I set the flashes for f8 and went to 1/500 to underexpose ambient by 1.5 stops thinking the flashes would light up Tara's face and the graffiti in the background. (I had one flash pointed at the background on a Wein peanut that wasn't working).
I put a diffuser dome over one of the flashes, which cost me a stop. I tried to boost the power of the flash, but didn't achieve much. For this shot, I used a gridded snoot close in to the face from camera right and had a reflector bounce light from camera left.
To get the shot I was looking for, I should have waited until dusk and let the ambient fall enough so the strobes could be the dominating light.
Kudos to Tara, who is a real charm to work with, and to Matte, another shooter who lent a helping hand.