Abstract: Low-Cost LiDAR Lens Autofocus System for Cinema Cameras

—Nolan Juneau (Mentor: Richard A. Messner)

In the motion picture industry, one of a cinematographer’s jobs is to move the plane of focus of the camera’s lens to line up with a subject so that it is sharp and “in focus.” This job is usually fulfilled manually by an assistant cameraperson (or “focus puller”), but sometimes, manual focus pulling is impractical. This is especially true for extremely technical shots on high-end shoots or for lower-budget shoots that cannot afford extra crew members. In recent years, systems have been created to pull focus automatically (known as “autofocus”), but many of the technologies that exist for cinema equipment are either limited in functionality or prohibitively expensive for independent filmmakers. With the proliferation of inexpensive LiDAR (Light Detection And Ranging) distance mapping technology, however, a similar autofocus system can now be constructed at a fraction of the price. With funding from a 2024 Summer Undergraduate Research Fellowship, I designed and constructed an all-in-one LiDAR autofocus system that achieves fast, automatic focusing up to a range of 9m (~30ft) in a system that can be easily adapted to any cinema camera, and with a total material cost of only $71.69 per unit.