Give a clip the look of a wet plate from the 1850s to the 1880s. Three things separate the plate from a plain black and white conversion, and the effect does each on every frame: the blue-biased response of the emulsion, highlights that stop at silver on a dark plate, and the surface of a hand-poured plate.
One plate, many frames
A real plate held one exposure. Here the plate is fixed and the picture moves: the pour edges, the drying marks and the specks stay in the same place for the whole clip, and only the image changes. Motion is the thing that breaks the illusion most, since plates needed seconds of exposure, so slow, steady shots read best.
Blue sensitivity, contrast and tone
Blue sensitivity blends from a standard luminance at 0 to the collodion response at 100, where skies blow out and red goes dark. Contrast sets the gain around the dark pivot of the plate; highlights stop at a cream silver with a gentle sheen. Tone moves the plate from cool blue-grey silver to warm brown.
Pour edges, drying marks and falloff
Pour edges sets how far the bare plate reaches in from the corners, with a milky thinning and a bright rim before the metal. Drying marks adds mottling, streaks and specks. Edge falloff softens the focus and darkens the plate away from the centre, as period lenses did.
Cost
About a quarter of a second per 720p frame on a laptop core. Set the export size before exporting a long clip at 4K.