PC-socket, greatly magnified
General specifications
Hot pluggable	Yes
Audio signal	None
Video signal	None
Pins	2

A Prontor-Compur connection (also known as a PC connector, PC terminal, or PC socket) is a standard 3.5 mm (1/8") electrical connector (as defined in ISO 519^[1]) used in photography to synchronize the shutter to the flash.^[2]

Etymology[edit]

"Prontor" has its origins in the Italian word "pronto", meaning ready (and was a leaf shutter made by Alfred Gauthier [de]).^[3] "Compur" is derived from the word "compound" (the "Compound [de]" was a long-lived series of leaf shutters made by Friedrich Deckel).

History[edit]

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. Gauthier [de] (which made the Prontor-S and Prontor SV models, amongst others) and Deckel (the Synchro-Compur model, successor to the Compound model).

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, owing to the fact that the Zeiss organisation held a significant shareholding in both of these companies prior to the introduction of the shared connector.^[4] By the 1950s, Gauthier were manufacturing up to 10,000 Prontor shutters daily.

The Gauthier company's essence lives on as Prontor GmbH [de], which is a wholly owned subsidiary of VTC Industrieholding GmbH [de].^[5] The Deckel company went bankrupt in 1994.^{[citation needed]}

References[edit]