La prospettiva per angolo tra Pozzo e Bibiena. Una questione di diritti d’autore

Angle perspective between Pozzo and Bibiena: an issue of copyrights Between 17th and 18th centuries, we glimpse the terms of an imaginary dispute between two of the greatest experts and disseminators of perspective technique, Andrea Pozzo and Ferdinando Galli Bibiena. The issue – never directly addressed – concerns the authorship of the conception of what is known as ‘angle perspective’. The rotation of real space with respect to the picture plane is one of the elements around which perspective theory has been going around for at least two hundred years when Pozzo introduced into his theoretical work the concept of ‘veduta per angolo’ and the interesting definition of ‘quasi per angolo’, when the angle that one of the main directions of the triorthogonal triple x, y, z, forms with the picture plane is different from 45°. Galli Bibiena’s treatise takes up the issue introducing small variations that lead him to propose himself as the originator of this approach. Both Pozzo and Ferdinando link the angle perspective construction to stage design and theatre. Notwithstanding the acknowledged influence of stage design, the veduta per angolo seems to have had another precedent, during the 17th century, with the development of anamorphosis and the consequent deformation of the image for spectators who are not standing in the point of constrained view. In this panorama, the primogeniture of non-frontal perspective construction must be sought well beyond the relationship between Pozzo and Bibiena, although it is undoubtedly at this time that a series of instances and technological advances lead the observer of perspective to assume a less static role. Space itself seems to become more flexible, and the concept of illusory enlargement is freed from the rigidity of the architectural and anthropometric nature of real space, and this allowed wall decoration to conceive free and imaginative inventions, which would be so successful in Europe and overseas.

Come è noto, tra il Seicento e il Settecento si possono individuare i termini di una immaginaria querelle tra due dei massimi esperti e divulgatori della tecnica prospettica. La questione, mai affrontata in maniera diretta, riguarda la paternità della ideazione di quella che viene definita “prospettiva per angolo”. I due poli del prospettivismo sembrano essere, nell’arco temporale che va dalle ultime decadi del Seicento alle prime del secolo successivo, Roma, dove la prospettiva decora gli spazi del potere ecclesiastico e gli ambienti delle dimore private delle classi altolocate da almeno due secoli, e Bologna, centro di notevole importanza per lo sviluppo di una cultura legata, in particolare, ai palazzi signorili e nobiliari e alla scenografia teatrale. I nomi intorno ai quali ruota questa querelle sono quelli di Andrea Pozzo e di Ferdinando Galli Bibiena, figure, che, a fianco di ricche e prestigiose carriere operative, hanno dedicato tempo alla divulgazione delle loro conoscenze lasciandoci importanti trattati a cavallo tra pratica e teoria.