While Leon Battista Alberti's De Pictura has certainly provided a set of seminal critical categories and working procedures for artists to follow, such as perspective-oriented principles, his treatise was responsible also for codifying new paradigms of perception, reception and evaluation of pictorial images. This essay explores significant examples of Alberti's ethics of the gaze, embedded in the concept of « risguardatore », examining how this unprecedented focus on the stylistic devices and the technical innovations applied in the making of Renaissance paintings have ultimately contributed to the definition of a 'learned' spectatorship amongst humanists.