The Letterphot was a basic headline typesetter assembled on the column and base of a photo enlarger. A head containing light sources, the font disc and a lens was attached to the column above the base. Characters were projected one at a time down onto a luminescent surface to assemble an image of the entire line. A strip of lithographic film was then placed on the luminescent surface. Each character was projected a second time and aligned with the luminescent image using light that wouldn't expose the film. Finally, the character was projected to expose the film. The film was then developed in a tray that was part of the base (Lechêne 2025;  Schmitt 1976, 70;  Goldbach 2025). (The descriptions I've found of the process are vague, so corrections or additions are welcome.)