One of my quick-and-easy methods of shooting outdoor portraits is to position the subject with the sun at their back and then fill in their faces with an on camera flash. While this method of lighting is probably considered somewhat remedial for many experienced photographers, it is a technique that I get asked about on a fairly regular basis.
For this portrait of Bret and Jarica, I waited until the setting sun was just above a nearby building (the Federal Courthouse in downtown Salt Lake City) and the shade line was closing in on the bench they were sitting on. By waiting for the last few minutes of sunlight, the background was almost entirely in shade. I positioned the bench so that the sunlight would provide a rimlight around Bret and splash a small amount onto his face.
Once I had the subjects in position, I adjusted the flash compensation of my on-board flash (Canon 580EX II) to fill in the shade with a natural looking light. I accomplished this with a minus 1 f/stop setting relative to the natural light. The camera was set to A/V (aperture priority) setting with the lens wide open at f/4.
When I have an assistant with me I will frequently shoot a portrait like this with reflector light to fill in the faces. However, on an evening like this one where I was working alone, a strobe created fill light serves as a nice substitute.
Canon 5D Mark II, Canon 70-200 f/4L lens – 1/400 second, f/4, ISO 400