The designation 'Alzaga Caravaggio' was coined as a tribute to Martin de Alzaga whose efforts, starting in 1967, led to the widespread recognition of this picture, now in Detroit, as the lost original of a work previously known through copies. The Conversion belonged to Ottavio Costa, who also owned The Ecstasy of St. Francis (Plate 6) and it seems to have been given by him c. 1606/07 to to his friend and business associate Giovanni Enriquez de Herrera, better known to posterity for his patronage of Annibale Carracci. In this picture Caravaggio followed the convention of identifying the Magdalen with Mary of Bethany, and gave a new implication to the traditional theme of the two sisters by portraying their relationship dramatically and, more especially, in terms of light and shade. Instead of the usual symbolic contrast between Martha, as indicative of the active life, and Mary, of the contemplative, he has chosen to depict the precise moment of the Magdalen's conversion when, rejecting her former life of sensuality and vanity, symbolized by the mirror, she succumbs, no doubt partially in response to her sister's words, to the meaning of Christian love and is both literally and metaphorically illuminated. The Conversion is one of the earliest instances of Caravaggio employing strong contrasts of light and shade, (chiaroscuro) to give a visual dimension to spiritual experience. The psychological drama is further enhanced by depicting Martha's mouth dropping open in wonder at her sister's sudden conversion, in a manner which recalls the right-hand figure in The Cardsharpers. The picture is also notable for Caravaggio's apparent use, in certain passages, of an unusual 'wet-on-wet' application of tempera on oil.