Here is an image where I used the sun, to overpower itself (face only), in a sense, because the mirror in the image reflected natural sunlight into the model's face which was reflecting less light than the mirror--all done with natural light, and if you want to see the story on what caused the image originally, here's the link:
http://rolandogomez.net/2008/10/obse...eads-to-photo/
Thanks, rg sends!
Overpowering the sun without flash example...