📷 Film Camera Exposure: Focal-Plane Shutter Slit, Reciprocity and Flash Sync (2D)

Front view of a film frame crossed by a two-curtain focal-plane shutter. Set shutter time, aperture, film speed, scene brightness, curtain travel time and subject speed, and watch the slit sweep, the exposure error in stops and the skew of a moving subject. Reciprocity, uniform row exposure, flash sync and metering are computed, with four in-page numerical checks. An exposure companion to the 3D film camera.