Tonal distribution and glare assessment in cinematographic film scanners

Film scanners and imaging systems play a key role in preserving and restoring historically significant materials. In cinematography, the digitization of analog film is shaped by factors such as light source, sensor sensitivity, optical components, and proprietary in-camera processing. This paper focuses on a core feature of film scanners: tonal distribution, with special attention to lens glare (flare). We digitized a 35mm negative film test using various scanners from different labs and compared the gray-level outputs with spectrophotometric transmittance measurements to evaluate tone distribution and detect glare. Our results show marked differences in tone reproduction between scanners, driven by both hardware and in-camera processing. We also demonstrate that glare is a constant factor that limits the dynamic range and affects the fidelity of digital reproductions.