Background
Friedrich Risner was born around 1533 in Hersfeld, Hesse, Germany.
Hersfeld Abbey, Bad Hersfeld, Hesse, Germany
Gravestone from Friedrich Risner in Hersfeld Abbey
https://www.amazon.com/thesaurus-Alhazeni-crepusculis-ascensionibus-Hardcover/dp/B0799MFPH5/ref=sr_1_fkmr1_1?keywords=Opticae+thesaurus+Alhazeni+Arabis+libri+septem%2C+nunc+primum+editi.+Eiusdem+liber+de+crepusculis+et+nubium+ascensionibus.+Item+Vitellonis+thuringopoloni+libri+X.+Omnes+instaurati%2C+figuris+illustrati+et+aucti%2C+adiectis+etiam+in+Alhazenum+commentariis%2C+a+Federico+Risnero&qid=1575979932&s=books&sr=1-1-fkmr1
1572
mathematician optician philosopher scholars
Friedrich Risner was born around 1533 in Hersfeld, Hesse, Germany.
Risner spent most of his scholarly life as the protégé and colleague of Peter Ramus, the renowned anti-Aristotelian humanist, and educational reformer, who was accustomed to collaborating with younger scholars on mathematical subjects. Risner’s mathematical ability is evident from Ramus’ reference to his “assistant in mathematical studies, … Friedrich Risner, so well versed in mathematics”.
In his will, Ramus established a chair in mathematics at the Collège Royal de France and specified that Risner should be its first occupant. When legal disputes over the chair were settled in 1576, Risner accepted the salary but never lectured; he resigned a few months later and returned to his native Hesse, where he died after a long illness.
The collaboration of Ramus and Risner also resulted in the posthumous publication of Risner’s Opticae libri quatuor, which later influenced Snell. It seems that the book was begun during the early years of Ramus and Risner’s association; and it is probable that the basic outline was Ramus’, while Risner was given the task of providing appropriate demonstrations and discussion. Only the first of the four books is complete, however, and the final two consist of little more than the enunciations of the propositions. The work depends primarily on Witelo, although other ancient and medieval authors are also cited.