In this selection of studies, J.L. Mancha explores aspects of the development of medieval optics and astronomy, including some medieval antecedents of the work of early modern astronomers. The articles deal with Latin, Hebrew and Arabic texts, and the process of translation and transmission of knowledge, and focus on three main themes. First, the theory and astronomical use of the pinhole camera in the 12th and 13th centuries; the texts edited here contain a solution to the problem of the formation of images cast by light through triangular apertures, equivalent to Kepler's, a description of...