HOW IT WORKS
A view thrown onto paper
The National Gallery describes a lens fixed to an opening in a darkened tent or box. Light from the view is projected on a much smaller scale inside, where it can be traced.
More on the device
BEFORE PHOTOGRAPHY
A dark box, a lens,
and a painter.
The camera obscura is the ancestor of the modern camera.
Light through a lens in a darkened tent or box throws a small image of the view onto a surface, where it can be traced. Some painters used it from the 17th century. The interesting question is how, and how much.
TRACED OR DRAWN? the evidence, case by case
Weigh the evidence- An aid, not a shortcut
- Sketches differ from finished work
- Look for the ruler lines
- Evidence over legend
THE SHORT ANSWER
Some sketches, yes.
Finished drawings, no.
For Canaletto, the answer depends on which works you mean.
Researchers and curators have tested both.
THE SKETCHES
A notebook of 140 pages
UCL emeritus professor Philip Steadman argues that Canaletto used a camera obscura for careful sketches of Venice's buildings, kept in a notebook in the Gallerie dell'Accademia.
Compare the cases
THE DRAWINGS
Pencil and ruler underneath
Infrared images studied by the Royal Collection Trust in 2017 showed meticulous pencil and ruler underdrawing beneath finished drawings, not tracing, the curator said.
How it was tested
HOW EXPERTS CHECK
Traced or drawn?
Look underneath.
Nobody can watch Canaletto work, so researchers compare and look beneath the ink. These are the methods used in the studies on this page.
Overlay the sketch
Steadman laid sketches digitally over a painting and over photographs taken from the artist's viewpoints in Venice to see how closely they match.
Rebuild the device
A reconstructed 18th-century tent camera showed sketches technically similar to Canaletto's were possible to make.
Look with infrared
Infrared rarely works on paper, but here it revealed the pencil underdrawing beneath Canaletto's pen and ink.
Read the lines
Ruled lines for buildings and reflections, and freehand birds, clouds and ripples, show a planned drawing rather than a traced image.
TWO NUMBERS WORTH KNOWING
An old claim,
tested with new tools.
One number for the sketches researchers have tested,
one for how long the claim has been around.
140 pages
Pages of Canaletto's Venice sketches
The notebook in the Gallerie dell'Accademia provided raw material for paintings of the 1730s and for finished drawings. Steadman superimposed its sketches digitally on a painting and on photographs.
SKETCHBOOK · ACCADEMIA
1771
When a biographer said he traced
A biographer wrote in 1771 that Canaletto used a camera obscura to trace key works, a claim disputed ever since. Infrared study in 2017 found his finished drawings were planned with pencil and ruler.
THE CLAIM · 1771
The National Gallery's own summary: Canaletto may have used a camera obscura for topographical accuracy in some designs, but he always cared about composition, not just recording views.
CASE BY CASE
Which work
are we talking about?
Pick a case to see what the sources say. The bar shows how strongly the evidence points to a camera obscura being used.
Summarised from the National Gallery, London, Drawing Matter (Philip Steadman) and reports of the Royal Collection Trust's 2017 infrared study.
THE DEVICE
Ancestor of
the camera.
The National Gallery calls the camera obscura an optical device that is the ancestor of modern cameras. From the 17th century some artists used it as an aid to plotting compositions.
A Royal Collection Trust spokesman described it in 2017 as a box that let artists trace an inverted image of a view, formed by rays of light passing through a small hole. Canaletto's notebook sketches, Steadman says, needed a bigger version: a booth or tent the artist worked inside.
Questions
Questions people ask
What is a camera obscura?
An optical device, the ancestor of the modern camera. A lens in an opening of a darkened tent or box projects a smaller image of the view inside, where it can be traced.
Did Canaletto use one?
The National Gallery says it is known to have been used by Canaletto. Steadman links it to his Venice sketchbook, while the Royal Collection Trust's 2017 study found his finished drawings were drawn with pencil and ruler, not traced.
Is the image upside down?
Yes. The Royal Collection Trust described the device as letting artists trace an inverted image of a view formed by light through a small hole.
Did Vermeer use a camera obscura?
The National Gallery says the Delft artists Fabritius and Vermeer may have experimented with it. That is a possibility, not an established fact.
Does using one make a painting less skilled?
The National Gallery notes that Canaletto always remained concerned with satisfying compositional design, not simply slavishly recording views.
Sources
- National Gallery, London: Glossary, Camera obscura
- National Gallery, London: Canaletto (1697-1768)
- Drawing Matter Journal: Philip Steadman, Canaletto's Venetian Sketches and the Camera Obscura
- Report (April 2017): Royal Collection Trust, Canaletto did not trace his drawings
Updated