Caravaggio
Michelangelo Merisi da Caravaggio was one of the most revolutionary figures of European art. He trained in Milan and he was active in Rome, Naples, Malta and Sicily. He created realism with the use of light. In his paintings he used a focused light source from high up, without reflections, a room with a single window and black walls. In this way, the lit and shadowed areas are very light and very dark and give enormous three-dimensionality to the painting; also the light was important to enhance the dramatic impact and give the figures a quality of immediacy.
The incredulity of Saint Thomas: it's a painting of Saint Thomas by Caravaggio. It is housed in the Sanssouci Picture Gallery. It shows the episode that gave rise to the term "Doubting Thomas" which had been frequently represented in Christian art since at least the 5th century. According to St John's Gospel, Thomas the Apostle missed one of Jesus's appearances after His resurrection. He didn't believe in Jesus's resurrection because he wanted to see with his eyes and touch with his hands the wound. So Jesus invited him to touch the wound. In the painting, Thomas's face shows surprise. The work is in chiaroscuro and the absence of halo emphasizes the corporeality of the risen Christ.