Which documentary form utilizes an unobtrusive camera to reduce filmmaker bias?

The observational documentary form is designed to minimize the filmmaker's influence on the subject matter, allowing viewers to witness events as they naturally unfold. This approach relies on an unobtrusive camera style, emphasizing a "fly on the wall" perspective where the filmmaker remains invisible to the subjects being documented. By employing this technique, observational documentaries aim to present a more authentic representation of reality, giving audiences the impression that they are experiencing events in real-time without any manipulation or commentary from the filmmaker. This contrasts with other forms such as expository, narrative, or performative documentaries, which may involve a more directorial presence, commentary, or dramatization.

The expository form often contains a narrator’s voice guiding the audience, while narrative documentaries tell a specific story with a clear structure and characters. Performative documentaries focus on the filmmaker's personal engagement with the subject, leading to a subjective representation. Each of these styles incorporates a level of bias or interpretation that the observational form intentionally aims to avoid.