Friedrich Risner

Friedrich Risner (c.1533 – 15 September 1580) was a German mathematician from Hersfeld in Hesse. He was a student of Petrus Ramus (1515-1572) and was the first chair of mathematics at Collège Royale de France. Friedrich Risner is known for his 1572 publication of Opticae thesaurus: Alhazeni Arabis libri septem, nuncprimum editi; Eiusdem liber De Crepusculis et nubium ascensionibus, Item Vitellonis Thuringopoloni libri X, an edition of works by Ibn al-Haitham and Erazmus Ciolek Witelo, two men who were both pioneers in the field of optics. The publication became a major benefit to a number of mathematicians and scientists, such as Kepler, Huygens, and Descartes. He also was the first one, suggesting the idea of a portable Camera Obscura, a lightweight wooden hut that had small holes fitted with lenses in each wall, and a cube of paper placed in the centre for drawing which led to the modern camera. After the St Bartholomew’s Day massacre (1572) Risner fled back to Hersfeld and died there eight years later. Risner was buried in Hersfeld Abbey.