In: Early Science and Medicine
Author: Sven Dupré

Abstract

Leonardo's drawings of optical machinery have been used (by David Hockney and others) as evidence for the claim that Leonardo built machines to make concave mirrors with which he could project images. This paper argues that Leonardo's drawings cannot be used as evidence for this claim. It will be shown that Leonardo used the drawings to communicate with his patrons and craftsmen, to experiment on paper, to record trials with models, and to think about 'theoretical' problems in optics. At both the theoretical and the practical level, Leonardo was only concerned with the burning properties of concave mirrors, not with their imaging properties. The paper will conclude that the drawings of optical machinery allowed Leonardo to differentiate himself from the ordinary mirror-makers in his workshop. The same drawings, however, also forced him to remain within the conceptual framework of perspectivist optics.

In: Early Science and Medicine
Author: Sven Dupré

Abstract

In his Paralipomena (1604) Johannes Kepler reported an experimentum that he had seen in the Dresden Kunstkammer. In one of the rooms there, which had been turned in its entirety into a camera obscura, he had witnessed the images formed by a lens. I discuss the role of this experiment in the development and foundation of his new theory of optical imagery, which made a distinction between two concepts of image, pictura and imago. My focus is on how Kepler used his report of the experiment inside the camera obscura to criticize the account of image formation given in Giovanbattista Della Porta's Magia naturalis (1589). I argue that this experiment allowed Kepler to sort out the confusion between images 'in the air'—referring to the geometrical locus of images in the perspectivist tradition of optics—and the experimentally produced 'projected images', which were empirically familiar but conceptually alien to perspectivist optics.

In: Early Science and Medicine
Author: SVEN DUPRE

Abstract

title RIASSUNTO /title Questo articolo tratta di un particolare tipo di strumenti ottici, gli orologi a rifrazione costruiti nel secolo XVI, collocandoli nel contesto delle conoscenze ottiche contemporanee. Verranno affrontate in primo luogo le propriet delle meridiane a rifrazione e la loro introduzione nel XVI secolo a opera del costruttore di strumenti tedesco Georg Hartmann. Si mostrer poi il modo in cui questi orologi a rifrazione venivano costruiti nel '500. Attraverso l'analisi delle note di Ettore Ausonio, il presente saggio sostiene che la procedura utilizzata dai disegnatori di strumenti del XVI secolo per la realizzazione di orologi a rifrazione si fondava sulle conoscenze della rifrazione contemporanee.

In: Nuncius
Author: Sven Dupré

Sven Dupré: The value of glass and the translation of artisanal knowledge in early modern Antwerp

In: Netherlands Yearbook for History of Art / Nederlands Kunsthistorisch Jaarboek Online
In: Nuncius
Author: SVEN DUPRE

Abstract

title RIASSUNTO /title L'articolo, nel quale vengono presi in esame gli studi di ottica di Galileo precedenti all'utilizzazione del cannocchiale, cercher di dimostrare come l'anacronistica distinzione tra arte e scienza abbia oscurato il reale significato dell'ottica galileiana. L'attenzione concentrata in maniera particolare su di un documento poco conosciuto contenuto nel MS Gal. 83, Theorica speculi concavi sphaerici, che sempre risultato di difficile intepretazione, perch le sue relazioni con le reali tradizioni di ricerca in cui si mossa l'opera galileiana non sono mai state ben comprese.

In: Nuncius