With the recent advances in surface analytical instrumentation, a methodology now exists which enables optical thin films to be studied in considerable detail. Scanning Auger spectroscopy with argon ion etching capabilities in conjunction with scanning electron microscopy, backscatter electron microscopy, optical microscopy, and light element energy dispersive x-ray spectroscopy have been successfully used at the University of Dayton to study coating defects and radiation induced damage in a variety of specimens. A brief description of the capabilities and limitations of some of these techniques will be given. Ball cratering, a relatively obscure technique by which underlying layers in an optical stack can be exposed, has proven to be a power- ful tool which has extended the range of the above mentioned analytical techniques. Some examples of adhesion failures, crack phenomena, substrate and film failures, and Auger depth profiling will be presented.