Hi All! This portrait is really exciting for me and scarry for me also! On a recent trip I was reading a great book by Joe McNally called The Moment it Clicks. This book has amazing information for any aspiring or professional photographer. Joe is very nice to share technique as well as style with the reader. The image you see below is based heavily on a picture on page 72 from the book. This image was made about one hour before sunset. I took a number of shots of the background to get the right mood. This was faster than the normal /250 flash sync speed, but with Nikon's Creative Lighting System (CLS) I was able to forget about trying to compensate for that and just focus on getting the right mood. I was using the SU-800 to remotely fire off my single SB-800 which my assistant is holding.
My technique was to have an assistant in the water on the left hand side just outside of the range of the field of view firing the flash into my subjects face. I was also aware that the water would reflect a great deal of light back up into my subjects shadowed side of the face. My largest fear was falling in the water myself. I am knee deep in the lake and the bottom is rather slippery! I didn't take to many precautions and lucky had no issues with the camera, the flash or my model.
My camera specs are: Nikon D200, fitted with a 17-55 mm lens at 28 mm, F/2.5 @ 1/1600 second, ISO 100. Hope this provides some inspiration.