the edge of the filmstrip this reduces damage and excessive wear to the filmstrip the photographic filmstrip 14 includes a magnetic recording material that is deposited on the film or is formed with the film emulsion or substrate in the preferred embodiment the filmstrip has a magnetic recording material that is deposited in a thin transparent layer over the entire surface of the filmstrip and is referred to as the magnetics on film mof layer 30 fig2 as the filmstrip is advanced through the camera a sequence of frames 24 are exposed the frames define a top edge 26 of the filmstrip and define a bottom edge 28 of the filmstrip when the frames are oriented for correct viewing the data tracks 22 extend along the bottom edge 28 of the filmstrip and are written into the mof layer as the frames 24 are exposed in a data recording camera more particularly the combined magnetic optical read head 20 includes multiple magnetic read heads 32 34 36 and includes an optical detector 38 the optical detector has a field of view 39 that encompasses the portion of the predetermined optical pattern 16 that extends beyond the edge of the filmstrip 14 and also encompasses a portion of the filmstrip including the bottom edge 28 as noted above the head assembly 18 will be properly positioned as the filmstrip is run through the printer 10 if the portion of the optical detector field of view filled with the optical pattern remains constant in comparison to.