Comparison 4: Caravaggio Lights the Way
Caravaggio (Michelangelo Merisi)
Conversion of Saint Paul on the Way to Damascus (1601)
Oil on canvas, W175 cm x H230 cm (68.9" x 90.6")
Cerasi Chapel in the Basilica of Santa Maria del Popolo, Rome, Italy
Tenebrism, that maximum-contrast, spotlight-esque lighting mentioned in the original Crespi post, effectively started with Caravaggio — or at least he made it so much his own that it may as well have.
Aside from using it to push the drama, Caravaggio also occasionally used the strong one-directional light in his work to suggest a sort of spiritual visitation or divine revelation (the 'light of God', as it were). In the painting at top, he shows the New Testament conversion story in which the Roman Pharisee Saul, who zealously persecuted Christians, was traveling on the road to Damascus with orders to arrest followers of Jesus when light flashed around him, he was struck off his horse blind, and he heard the voice of God; he subsequently converted to Christianity and became the apostle Paul. Caravaggio's version gives us a man with arms outstretched in religious ecstasy, eyes closed/blind but in a picture that has been flooded with strong light pouring in from a single point above — all in all, highly suggestive that while Saul/Paul is blind, he is now 'seeing' the overwhelming light of God's truth from heaven.
Crespi, painting about a century after Caravaggio, seems to put his light to similarly symbolic use. I suggested in the original post that that tiny candle throwing such enormous light may be symbolic of Psyche's enormous discovery, and/or her simple choice to look having such large consequences. But since the lighting Crespi used would also have been reminiscent of many religious works in the tradition started by Caravaggio, the lighting choice here may also have helped to amplify the mythological nature of the work, tying it back to 'god-light'. (Alternatively, that 'god-light' look might encourage the viewer to look for religious messages laid over the pre-Christian story.)