Renowned British artist David Hockney has ignited a significant debate within the art world with his new book, 'Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters'. In this compelling work, Hockney posits that many European painters, particularly from the early 15th century, employed optical devices such as mirrors and lenses to achieve the striking realism and precision evident in their masterpieces.
Hockney's inquiry began with a conviction that Jean-Auguste-Dominique Ingres utilised a camera lucida – a small prism on a stalk – for swift portrait likenesses. However, the core of his theory extends to the broader use of the camera obscura, a darkened room or box that projects an image of the external world onto a surface. This technique, Hockney argues, allowed artists to capture intricate details and perspectives with a fidelity previously unachieved, challenging long-held assumptions about the pure observational skill of these artists.
The book is heavily illustrated, with the visual evidence forming a crucial part of Hockney's argument. He provides detailed technical notes on various paintings, pointing out anomalies in perspective, proportion, and finish that he believes are clues to the use of projected images. For instance, Hockney suggests that the monocular view inherent in lens-based projection differs from human binocular vision, potentially leading to specific visual characteristics in the art. He also notes that painters working with a camera obscura would only have a small part of their subject in focus at any given time, leading to a composite approach that could subtly embed a sense of time and movement into the final piece as light sources shifted.
Hockney particularly focuses on the period around 1600, identifying Caravaggio as a pivotal figure whose work exhibits a unique optical novelty and immediacy. He argues that some of Caravaggio's paintings, with their 'coldly precise, voluptuously real and strangely oneiric' qualities, suggest the use of optical aids. Caravaggio's presence in Rome from 1595, a hub of scientific experimentation frequented by figures like Galileo, and his patron's access to Da Vinci's unpublished writings on art and science, further support Hockney's hypothesis.
The publication includes an anthology of writings on optics spanning a millennium, alongside correspondence between Hockney and various academics discussing his research. This supplementary material underscores the depth of his investigation and the scholarly engagement his theory has provoked, positioning 'Secret Knowledge' not just as an artistic observation but as a significant contribution to art historical discourse.