This book appears as a rare find in the Spanish bibliographic landscape dedicated to photography, and there are not many titles with similar content among specialized foreign publications. It is a technical compendium that offers a wealth of interesting and in-depth content. The title chosen by the author, Luna cornata, takes us back to the time of medieval alchemists, who referred to silver chloride by this name, whose property of darkening under the effect of light forms the basic pillar of photography in its chemical aspect, alongside the optical one. The sum of information contained in this book is overwhelming, supported by a solid bibliography, both Spanish and foreign. The numerous citations in the text that refer to much of this abundant information indicate that Rosell Meseguer has not limited herself to establishing a list of titles but has thoroughly examined them.