A methodology for the design of a filter to image the bottom of a contact is developed through simulation. Without a filter, the topography of the hole causes normally incident light to refract out of the hole. By conditioning the light with a filter, however, light is launched into the hole that is capable of propagating down the hole and imaging the bottom. When using this filter, the reflected aerial image differs by as much as 10% when the contact hole is under etched by 0.05 mu m. Although, this initial success shows that the filter is capable of imaging the bottom of the hole, the introduction of process variations such as a larger hole diameter or a thinner oxide cause large deviations in the aerial image.