Photo technique points to great painter's secret

Italian Renaissance painter Caravaggio used revolutionary optical instruments to "photograph" his models more than 200 years before the camera was invented, according to a researcher in Florence.

The 16th century artist celebrated for his dramatic chiaroscuro (light and shadow) paintings mastered "a whole set of techniques that are the basis of photography," Roberta Lapucci said.

Caravaggio worked in a "darkroom" and illuminated his models through a hole in the ceiling, said Lapucci, who teaches at the prestigious Studio Art Centres International in the Tuscan capital.