Patent ID: 6301442
Filing Date: 2001-10-09
Classification: G03B

Abstract:
An optical instrument for photographing an object, comprising an electronic flash unit for applying flash light to said object, a taking lens for directing object light from said object to an exposure station to form a color image, wherein recording medium photographically, electrically or magnetically records said color image photographed in said exposure station;said optical instrument satisfying a condition of:0.ltoreq..DELTA.E.ltoreq.0.08where .DELTA.E is a light source color difference amount between said flash unit and a white fluorescent lamp of F6 type, and obtained from a condition of:.DELTA.E= [(X.sub.1 -X.sub.2).sup.2 +(Y.sub.1 -Y.sub.2).sup.2 ]where X.sub.1, Y.sub.1, X.sub.2 and Y.sub.2 are obtained from conditions of:X.sub.1 =[(RF-R0)-(GF-G0)]-[(BF-B0)-(GF-G0)]/2Y.sub.1 =[(BF-B0)-(GF-G0)].times.sin (.pi./3)X.sub.2 =[(RS-R0)-(GS-G0)]-[(BS-B0)-(GS-G0)]/2Y.sub.2 =[(BS-B0)-(GS-G0)].times.sin (.pi./3)where RF, GF and BF are Status-M converted density of red, green and blue colors of a gray reference reflector plate having a reflectance factor of 18%, said Status-M converted density being obtained by illuminating said gray reflector plate with said white fluorescent lamp of said F6 type, and by photographing an image of said gray reflector plate in said exposure station;RS, GS and BS are Status-M converted density of said red, green and blue colors of said gray reflector plate, said Status-M converted density being obtained by illuminating said gray reflector plate with said flash unit, and by photographing an image of said gray reflector plate in said exposure station;R0, G0 and B0 are Status-M converted density of said red, green and blue colors of said gray reflector plate, said Status-M converted density being obtained by illuminating said gray reflector plate with a standard light source C, and by photographing an image of said gray reflector plate in said exposure station.