Complex sentence: An ironworker with a strong resemblance to Dreyfus was hired for the role in order to increase the film's realism; according to the film historian Jay Leyda, the effect was so convincing that European audiences believed they were watching actual documentary film of the events.
Split into simpler sentences: An ironworker with a strong resemblance to Dreyfus was hired for the role in order to increase the film's realism. According to the film historian Jay Leyda, the film's emphasis on realism was so convincing that European audiences believed they were watching actual documentary film of the events.