I used the @Lencarta Safari portable flash set-up for this shot. A gridded reflector fired into Catherine's hair and a plain reflector was the key light. A long-ish shutter speed exposed the background, but Catherine is super-sharp as very little ambient light fell on her. (Flash fires in an instant).
Canon EOS 5D Mark II, f/7.1 @ 85 mm, 1/3, ISO 100,