I received a bunch of comments and emails regarding this portrait. Many of you couldn't believe that this portrait was shot with just one light source. The image does appear as if it has more than one light source and to a certain degree it has 3-4 light sources, but all the light is coming from one large softbox (74"x100") powered by one strobe (Jinbei HD-610). The look is accomplished with the use of a black flag. This flag also serves as a background as seen in the image below.
One more flag is used in front of the camera to guard against lens flare (seen in cardboard). Just cut a hole with the appropriate ratio and place it in front of the camera in order to cover the flare. Usually I would use a black flag but for demonstration purposes I used a cardboard one, also because I forgot my flag at home and made this one, lol. So when the flash goes off the light will come from all four sides acting like 4 distinct light sources. A white reflector was used camera left to bounce some light towards her face. If the model has dark hair you might need a second reflector camera right to illuminate her hair. You can then move the softbox around to increase or decrease the light coming from a certain direction. In addition, moving the softbox forward or backwards would increase or decrease the width of the rim light. I will be making a video soon showing how this method in action. I really love this rim lighting setup. I gives such a cool glow around her. Try this setup for yourself and see how many different looks you can get. I included the lighting chart for your convenience. Let me know how it goes!!