How did Vermeer paint his masterpiece?
2 January 2014 Last updated at 00:10 GMT
A new documentary explores the possibility that the 17th century Dutch painter Vermeer used a camera obscura - an optical device that projects an image of its surroundings onto a screen - to create one of his masterpieces.
If this was the case then it would challenge the view that the artist had an incredible innate ability to paint with such accurate and precise detail.
Talking Movies' Tom Brook reports.