Portrait of Martin Luther with an appearance true to his time

Portrait of Martin Luther with an appearance true to his time. He is dressed in a heavy black cloak and a period hat, 16th-century characteristics. His hair is short and his face features a well-trimmed beard. Luther should have an expression of firmness and introspection, reflecting his influence as a reformer. The background can be an office environment or a study room of the time, with books and historical documents around him. The lighting should highlight his face and clothing, capturing the seriousness and importance of his historical figure."