Depth of field verifying device

Claim 1

DIAPHRAGM MEANS FOR A SINGLE LENS REFLEX CAMERA, COMPRISING A PLURALITY OF DIAPHRAGM LEAVES, WHICH FORM AN APERATURE OF VARIABLE DIAMETER, EACH LEAF BEING PROVIDED WITH A FIRST PIN AND A SECOND PIN, A FIRST DIAPHRAGM OPERATING DISC MOUNTED COAXIALLY OF SAID SINGLE LENS PROVIDED WITH PLURALITY OF APERTURES EACH TO RECEIVE SAID FIRST PIN OF ONE OF SAID LEAVES, A SECOND DIAPHRAGM OPERATING DISC MOUNTED COAXIALLY OF SAID SINGLE LENS PROVIDED WITH A PLURALITY OF SLOTS EACH TO RECEIVE THE SAID SECOND PIN OF ON OF SAID LEAVES, SAID SLOTS BEING OF GENERALLY V FORM, ONE ARM OF THE V BEING ARCUATE CONCENTRIC WITH SAID APERTURE, THE OTHER ARM OF THE V BEING GENERALLY STRAIGHT AND PARALLEL TO A TANGENT TO SAID APERTURE, ONE OF SAID DISCS BEING ADAPTED TO ROTATE IN ONE DIRECTION THROUGH A FIXED ANGLE TO OPEN THE DIAPHRAGM FOR VIEW FINDING, AND MOVABLE THROUGH THE SAME FIXED ANGLE IN THE OPPOSITE DIRECTION TO CLOSE THE DIAPHRAGM AS REQUIRED FOR PICTURE TAKING, THE OTHER SAID DISC BEING ADJUSTABLY ROTATABLE TO DETERMINE THE DIAPHRAGM OPENING SIZE WHEN SAID ONE OF SAID DISCS IS IN THE POSITION FOR PICTURE TAKING, SAID SECOND PINS OF EACH SAID LEAF LYING IN THE ARCUATE PORTION OF ITA CORRESPONDING V-SHAPED SLOT WHEN ONE OF SAID DISCS IS ROTATED TO OPEN THE DIAPHRAGM FOR VIEW FINDING AND LYING IN THE OTHER ARM OF SAID V-SHAPED SLOT WHEN ROTATED TO THE POSITION FOR PICTURE TAKING, THE POSITION IN SAID GENERALLY STRAIGHT PORTION OF SAID V-SHAPED SLOT OF SAID SECOND PIN BEING DERERMINED BY THE ADJUSTMENT OF THE OTHER OF SAID DISCS TO DETERMINE THE DIAPHRAGM OPENING SIZE FOR PICTURE TAKING.