Aerial camera

Claim 1

AN AERIAL STRIP CAMERA FOR PRODUCING A STEREOSCOPIC PICTURE OF A SCENE, SAID CAMERA MOUNTED IN A VEHICLE FOR TRANSPORTING SAID CAMERA OVER SAID SCENE IN A PREDETERMINED DIRECTION, SAID CAMERA COMPRISING: A SINGLE, WIDE ANGLE OF VIEW, LONG FOCAL LENGTH CAMERA OBJECTIVE LENS SYSTEM, SAID LENS SYSTEM DEFINING A FOCAL PLANE AND A CAMERA AXIS OF SYMMETRY PASSING THROUGH THE PROJECTION CENTER OF SAID LENS SYSTEM SUBSTANTIALLY PERPENDICULAR TO SAID FOCAL PLANE IN THE PLANE OF SAID PREDETERMINED DIRECTION; A SOURCE OF FILM HAVING A BASE; A FIRST EMULSION LAYER DISPOSED ON SAID BASE SENSITIVE TO SUBSTANTIALLY ONLY A FIRST COMPLEMENTARY COLOR, AND A SECOND EMULSION LAYER DISPOSED ON SAID FIRST EMULSION LAYER SENSITIVE TO SUBSTANTIALLY ONLY A SECOND COMPLEMENTARY COLOR, SAID SOURCE INCLUDING MEANS FOR DISPOSING SAID FILM TO RECEIVE LIGHT PROJECTED BY SAID LENS SYSTEM; A FIRST AND A SECOND ELONGATED APERTURE SLIT EACH DISPOSED SUBSTANTIALLY IN SAID FOCAL PLANE, SAID SLITS HAVING PARALLEL, ELONGATED AXES TRANSVERSE TO SAID PREDETERMINED DIRECTION AND SYMMETRICAL ABOUT SAID CAMERA AXIS SUCH THAT SAID FIRST SLIT IS AFT OF SAID CAMERA AXIS TO DEFINE A FORWARD LOOKING PROJECTION AXIS THROUGH SAID PROJECTION CENTER AND SAID SECOND SLIT IS FORWARD OF SAID CAMERA AXIS TO DEFINE A REARWARD LOOKING PROJECTION AXIS THROUGH SAID PROJECTION CENTER; MEANS FOR TRANSPORTING SAID FILM AT A PREDETERMINED VELOCITY PAST SAID FIRST SLIT TO EXPOSE AN INCREMENTAL AREA OF ONE OF SAID LAYERS TO A PORTION OF SAID SCENE ALONG SAID FORWARD LOOKING PROJECTION AXIS AND FOR TRANSPORTING SAID INCREMENTAL AREA PAST SAID SECOND SLIT TO EXPOSE, AT A TIME INTERVAL PROPORTIONAL TO SAID PREDETERMINED VELOCITY, AN INCREMENTAL AREA OF THE OTHER OF SAID LAYERS THAT IS ALIGNED WITH SAID INCREMENTAL AREA OF SAID FIRST LAYER TO SAID PORTION OF SAID SCENE ALONG SAID REARWARD LOOKING PROJECTION AXIS, TO PRODUCE TWO SUPERPOSED, ALIGNED IMAGES OF SAID SCENE, WHICH WHEN LATER PROCESSED AND VIEWED, YIELDS A STEREOSCOPIC PICTURE OF SAID SCENE; MEANS FOR MEASURING THE TOTAL LUMINOUS FLUX PASSING THROUGH AT LEAST ONE OF SAID SLITS; MEANS COMPARING SAID LUMINOUS FLUX WITH A PREDETERMINED VALUE TO PROVIDE AN INDICATION PROPORTIONAL TO THE DIFFERENCE BETWEEN SAID PREDETERMINED VALUE AND SAID TOTAL LUMINOUS FLUX; AND MEANS RESPONSIVE TO SAID INDICATION TO VARY THE WIDTH OF SAID FIRST SLIT AND SAID SECOND SLIT TO MAINTAIN THE TOTAL EXPOSURE SUBSTANTIALLY CONSTANT.