JPS52-141223A1977Assignee: Mamiya Koki Co., Ltd.Inventors: Yusuke NanjoMAMIYA-SEKOR SFC 150mm f/4 SOFT FOCUS— 5 ELEMENTS / 3 GROUPS, f = 150.026 mm (MODELED)
JP1981-119109 A1981Assignee: Mamiya Koki Co., Ltd.Inventors: Yusuke NanjoMAMIYA-SEKOR ZOOM E 28-50mm f/3.5-4.5— 9 ELEMENTS / 8 GROUPS, 28-47.55 mm DESIGN / 28-50 mm MARKETED