A way of denoting emulsion position in 16mm film. Film can be wound emulsion in, or emulsion out. This can be important when exposing the camera film, but also later when indicating which way up the image is formed and on what side the perforations are located on a ‘single perf’ film.

To identify A-type on a bench the following formula is used: head to the right, perforations towards you, if the base (or the ‘cell side’) is upward, then it is A-type.

Please note that this formula does not work for double perforation 16mm.