The name of Thierry Odeyn is indissolubly linked to the documentary but in a multiple way. A graduate of INSAS where he has now been a professor for twenty-five years, he founded and developed the Réalité Line there with the collaboration of Michel Khleifi and Éric Pauwels. This educational function, which he extended by teaching at IHECS and ERG, has become central and primary. Also creative because he “invented” a requirement for the gaze, a long thoughtful approach to reality that has already trained several generations of young filmmakers in whom he has instilled the desire to bear witness to the world. He also leads training workshops in cinematographic language in various popular education settings.