[2] "Prontor" has its origins in the Italian word "pronto", meaning ready (and was a leaf shutter made by Alfred Gauthier [de]).

The term is derived from brands of widely marketed photographic leaf shutters manufactured from the early 1950s by two distinct, but now defunct German companies.

Both companies' brands, Prontor (from 1953) and Compur (from 1951), shared a common 1/8"-inch coaxial connector for shutter–flash synchronization.

This convergence of design is not as coincidental as it might first appear, as the Zeiss organisation held a significant shareholding in both of these companies prior to the introduction of the shared connector.

The Gauthier company's essence lives on as Prontor GmbH [de], which is a wholly owned subsidiary of VTC Industrieholding GmbH [de].