Photographic exposure measuring device

Claim 1

IN COMBINATION WITH A CAMERA HAVING A PREDETERMINED PHOTOGRAPHIC FIELD OF VIEW, AN EXPOSURE CONTROL SYSTEM COMPRISING MEANS MOVABLE FOR ADJUSTING EXPOSURE OF PHOTOSENTIVE MATERIAL IN SAID CAMERA; MANS RESPONSIVE TO AN ELECTRIC SIGNAL FOR POSITIONING SAID MOVABLE MEANS AS A FUNCTION OF A PREDETERMINED CHARACTERISTIC OF SAID SIGNAL; AT LEAST TWO PHOTORESPONSIVE MEANS ELECTRICALLY DIRECTLY CONNECTED IN ELECTRICALLY OPPOSED RELATION WITH SAID POSITIONING MEANS FOR JOINTLY REGULATING SAID MEANS FOR POSITIONING SAID MOVABLE MEANS AS A FUNCTION OF THE DIFFERENCE IN LUMINOUS FLUX FALLING RESPECTIVELY ON SAID PHOTORESPONSIVE MEANS, A FIRST ONE OF SAID PHOTORESPONSIVE MEANS BEING SUPPORTED BY SAID CAMERA IN A POSITION FOR ACCEPTING LIGHT FROM A FIRST SELECTED ZONE OF A SCENE LYING WITHIN SAID PHOTOGRAPHIC FIELD AND WHICH IS TO BE PHOTOGRAPHED, AND A SECOND ONE OF SAID PHOTORESPONSIVE MEANS BEING SUPPORTED BY SAID CAMERA INA POSITION FOR ACCEPTING LIGHT FROM A SECOND SELECTED ZONE OF SAID SCENE, BOTH OF SAID ZONES CONCURRENTLY LYING SUBSTANTIALLY COMPLETELY WITHIN SAID PHOTOGRAPHIC FIELD, AND EACH OF SAID PHOTORESPONSIVE MEANS BEING SHIELDED FROM LIGHT FROM OUTSIDE ITS RESPECTIVE ZONE.