Another correction .... the predominant Kodak process all along was never panchromatic, and involved prior separations either from color
transparencies, or direct in-camera black and white separations. The Pan Matrix product was a different approach directly from color negatives,
was far less common, and apparently, Ctein is the last practitioner of it due to the extinction of the special film itself. Ortho or blue sensitive matrix films are still being made and used, but not by Kodak, and not for general distribution at this time.