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) used in photography to synchronize the shutter to the flash.
Principia Cathedra the principals of the chair, from Latin cathedra, as a seat of authority and that which a cathedral's purpose is to indicate the location of such chair.
