This is an old revision of this page, as edited by CharlesHBennett(talk | contribs) at 19:19, 4 October 2011(expanded explanation of function of notches (e.g. recognizing emulsion side in the dark) and added link to extensive Louisville Library list of notch codes, including discontinued types.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.Revision as of 19:19, 4 October 2011 by CharlesHBennett(talk | contribs)(expanded explanation of function of notches (e.g. recognizing emulsion side in the dark) and added link to extensive Louisville Library list of notch codes, including discontinued types.)
A notch code is a set of notches or recesses cut into the edge of a piece of sheet film to provide a tactile way to identify the film brand, type, and processing chemistry (e.g. black and white, color negative, or color reversal) in the dark. It enables photographers to identify the emulsion side of the film when loading sheet film holders, and helps processing lab technicians avoid placing sheets in the wrong processor. After processing the notches serve as a permanent visual record of the same information. When the film is oriented vertically (portrait format), the notches are in the top edge near the upper right corner when the emulsion is faces the viewer.
An extensive listing of sheet film notch codes, mainly Kodak, including many discontinued types, can be found at the end of the University of Louisville Ekstrom Library's Acetate Negative Survey [1].