Acknowledgements FROM PATRICIA RUSSOTTI: This project first began three years ago during a discus- sion at an SPE conference in Miami with Diane Heppner, then Acquisitions Editor for Focal Press. I would like to extend my thanks to Diane for being supportive of this project from the very beginning. Since that time, it has been my great pleasure to work with Cara Anderson, Senior Acquisitions Editor and Danielle Monroe, Associate Acquisitions Editor at Focal. Two of the most patient, encouraging profes- sionals ­ what a great team! One could not ask for a better group to work with. I also know there are many opportunities that have been provided to me and for the students I have taught during my career at the Rochester Institute of Technology. I would like to thank my co-author Richard Anderson for his determination to spread "the word" and for sharing his knowledge. There are always many people to acknowledge when a project is completed. Richard mentions many of them in his acknowledgments and I add my thanks to each of them as well. A very special thanks to Dr. Therese Mulligan, Administrative Chair, Photographic Arts School of