When Canaletto’s biographer wrote in 1771 that he used a camera obscura to trace his key works, he set down in print a trope that would follow the artist for centuries.
Today, thanks to infrared technology, Canaletto is officially in the clear, as the Royal Collection Trust confirms the works they hold were sketched with pencil and ruler instead.
The institution has undertaken its first scientific examination of its Canaletto drawing collection; the largest in the world and containing more than a third of his surviving works.
The original marks made by the artist have now been seen for the first time in nearly 300 years, and have been hailed as “categorically” proving he did not trace the works using camera tricks.
Rosie Razzall, curator of prints and drawings, said they had been “just amazed” at the results, with entirely new information proving “really exciting”.
The drawings, along with the infrared images of the most interesting works, are to go on display at The Queen’s Gallery, Buckingham Palace, in May.
Infrared photography, often used on paintings but rarely for works on paper, allows conservators to see the original markings on drawings by Canaletto of the Grand Canal in Venice.
The technique identified pencil and carbon on the paper, in this instance showing the original sketch underneath the final pen and ink creation long seen and admired by the public.
The results, say the Royal Collection, give “extraordinary insight into Canaletto's artistic practices”.
In particular, they identify the extensive underdrawing of buildings, down to chimneys, windows and facades, and how the artist used a ruler to outline reflections in the water.
Experts can now see how he copied over the pencil lines in ink, before adding spontaneity with freehand birds, clouds and ripples on the water.
A spokesman for the Royal Collection Trust explained: “Canaletto is long thought to have used a camera obscura to achieve topographical accuracy in his work.
“A precursor of the modern camera, the device enabled artists to trace an inverted image of a view formed by rays of light passing through a small hole in a box.”
Works examined include six drawings of the Grand Canal, such as The central stretch of the Grand Canal, c.1734, and The Piazzetta looking towards Santa Maria della Salute, c.1723–4.
Rosie Razzall, who is co-curating the exhibition, said: ““We thought it would be fruitful to look at it under infrared and we were just amazed by the results.
“You get this image of Canaletto’s meticulous underdrawing, as he really, really carefully plans out the sheets with pencil and ruler.
“It’s fascinating from that point of view, and also for its wider significance.
“It shows very clear that he wasn’t using a camera obscura to make these drawings.”
Conservators are the first to see the pencil lines since they were drawn by the artist himself.
Asked of the significance of artists using a camera obscura, Razzell said the pictures created could be a “very accurate but somehow bland image, because it’s just a tracing”.
“It’s one of these tropes which has just been repeated since Canaletto’s lifetime,” she added. “His earliest biographer in 1771 wrote that he had used a camera obscura.
“It’s been often repeated and one of those things that’s debated about Canaletto. “The imaging shows categorically that these sheets were not made with a camera obscura.”
The drawings joined the Royal Collection after George III bought virtually the entire collection of Joseph Smith, a great art patron in Venice, in 1762.
They will go on display alongside works by Canaletto’s contemporaries, including Sebastiano and Marco Ricci, Rosalba Carriera, Francesco Zuccarelli, Giovanni Battista Piazzetta and Pietro Longhi.
Canaletto & the Art of Venice is at The Queen’s Gallery, Buckingham Palace, from May 19.