The Yale University Library, one of the earliest developers of preservation microfilming practices, is today engaged in the first stages of a long-term and comprehensive effort to develop practical systems for the conversion of microfilm to digital image, and thereby to develop an understanding of the appropriate relationship of the two technologies in future preservation practice. The first section of this report summarizes the results of the initial planning phase of the larger project. In the next section, a vision of the place of digital technology in a research library such as Yale's is articulated. The third section outlines an economy of choices and organization in which the conversion of microfilm to digital imagery might emerge as a viable preservation option. In the fourth section the architecture of a digital imaging system is mapped and critical issues of feasibility are identified. Finally, a plan of work for a demonstration project is presented which investigates the costs and benefits of conversion in the process of building a digitized library of 10,000 books from microfilm copy. (7 tables and figures) (MAB)