The painter produced "a powerful ray coming from a precise source, usually outside of the frame from the top right," and not the "universal and diffuse light" that was the norm at his time, she said.
Considering that another 15 Caravaggio paintings are already in Roman churches, Rome is the capital of the artist's work, she added.
Caravaggio, who died aged 39 in 1610, spent 14 years in Rome, reaching the height of his artistic career in the city.
The exhibition opens with the famous "Fruit Basket," a model of sobriety that recalls ancient Roman painting.
Some rooms are left in semi-darkness to allow viewers to plunge into Caravaggio's world.
Masterpieces include "The Musicians" from the Metropolitan Museum in New York, "The Lute Player" from the Hermitage in Saint Petersburg, Russia, and the "Deposition" from the Vatican Museums.
Caravaggio's subjects range from gambling to biblical episodes, but also illustrate his own turbulent life.
Michelangelo Merisi -- Caravaggio's real name -- arrived in Rome poor, but won fame and recognition before suddenly having to leave the city in 1606 after he was involved in a homicide.
The exhibit divides Caravaggio's life into three periods: his youth (1592-1599), his success (1600-1606) and his flight (1607-1610).
While showcasing the beauty of the best-known paintings, the exhibit also sheds light on the painter’s lesser-known works.
One surprise is Caravaggio’s "Saint John the Baptist" with his tormented and dreamy face.
Even before opening, the Caravaggio exhibit has sold 4,800 tickets, and 50,000 reservations have been made over the Internet, organisers said.
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